User talk:D.Lazard/Archive 3

Redirect of set notation
I have two concerns. First, on its merits I would have strongly argued against even merging it into set-builder notation, let alone eliminating the article and all of its contents.


 * I trust you will grant that "triviality" is in the eye of the beholder. The article covers not only notations, but also the thinking behind those notations. That is all useful material for those trying to understand how mathematical notation works and is developed, and it is addressed nowhere else on Wikipedia.


 * Nor was the page some backwater. According to its pageviews analysis, in 2019 it had over 100,000 views. That's over 9,000 views per month, and works out to roughly one view every 5 minutes, 24×7.


 * And although there had been a previous merge proposal, it had been closed out earlier today by user:Klbrain with the explanation that there had been "no case made for merge" and that there was also "no support over more than a year."

I would be pleased to lay out why I believe the contents is far from trivial as well as why the article on set-builder notation would be an inappropriate place for it, if there were actually a discussion of the pros and cons of a proposal to merge.

And that gets to my second concern—the way you did this. You effectively established a discussion period of eight whole minutes. And then you did not merge, you simply replaced with a redirect. And all of this even though Klbrain had pointed out only ninety minutes earlier that there had been no support for a merge at any point during a window that was more than a year long.

By the way, I could have just reverted your redirect. But rather than act unilaterally, and assume that your reasons for suggesting the merge were themselves "trivialities," I chose to discuss the matter with you, to understand your reasoning in the hopes that we could come to some agreement. I hope that's possible—PaulTanenbaum (talk) 12:55, 16 January 2020 (UTC)
 * The article (before my edit) is not sourced, and is not written in an encyclopedic tone, but looks like an essay (see WP:NOTESSAY). Except for some basic facts that belong either to Set (mathematics) or to Set builder notation, it contains only WP:Original research. So, by basic Wikipedia policies, this content does not belong to WP.
 * Some parts of the article are clerly presented as WP:OR, such as the end of the article after "An example where this cardinality-based convention appears not to have been used yet is X!"
 * The article contains factual errors such that the assertion that the empty set is a set of numbers
 * The part of the article that is not WP:OR is a redundant content fork of Set (mathematics) amd/or Set builder notation.
 * The article is misleading as not making any distinction between the facts of set theory that are independent from any notation, and the notations that may or may not be used for denoting them. For example the formula $$\{a,b,a\} = \{a,b\}= \{b,a\}$$ is not a property of the notation, but the notational transcription of a property of sets.
 * This makes many issues for a single article, and I am quite sure that, if you open a discussion on it at WP:WPM, there will be a consensurs in favour of my edit. D.Lazard (talk) 15:51, 16 January 2020 (UTC)


 * OK, I'm glad to know your thoughts, and I find them worthy of discussion. Indeed, some of your points I find quite fair. For instance, the article could do with some sourcing, but that's easily added. On the other hand for instance, how can you presume to indict it as WP:original research? Perhaps your acquaintance with the research literature—not to mention textbooks—is not so encyclopedic as you imagine? And anyway, wouldn't it be up to you to open that discussion? And to allow more than 8 minutes for it to take place?
 * On a side point, maybe you're right and there will be a consensus in favor of some edits—or even of your action (which I emphasize wasn't an "edit" but a deletion). But I do wonder how you can be so confident in your prediction given Klbrain's findings.—PaulTanenbaum (talk) 17:42, 16 January 2020 (UTC)

Clarification in article "Orthogonal group"
Hello! You have made several revisions to the article Orthogonal group, and I'm specifically wondering about this revision from 2 November 2019:

I think that the word "spacial" here is supposed to be "special". Can you confirm that this is what you meant? (The reason this came up is that I'm trying to fix instances where the word "spatial"-- having to do with space-- is misspelled as "spacial". I don't think this one fits that pattern, though). - Jkgree (talk) 19:26, 23 January 2020 (UTC)
 * This is clearly a typo, and I have fixed it. Thanks for pointing it. D.Lazard (talk) 20:38, 23 January 2020 (UTC)

A suggestion
I really like your definition of mathematics as "a science of abstract objects." How about editing the current lead section of the article to include this definition too? Ambuj Shukla (talk) 08:00, 30 January 2020 (UTC)
 * I have edited the first paragraph in this way. IMO, the remainder of the lead needs to be completely rewritten, but I have not a clear idea of what should be changed, and how formulate things. In any case, we must first wait to know whether there is a consensus to accept my edit.D.Lazard (talk) 09:08, 30 January 2020 (UTC)

Reversion of Krull dimension
Dear D. Lazard,

I disagree with your reversion of Krull dimension for the following reasons:
 * the original article suffered from a non homogeneous use of different symbols for the same object (e.g. I and I for a generic ideal),
 * and mixed use of Latex/non-Latex symbols in the same line (e.g. the first 6 lines of the Krull dimension, or Spec($$R$$));
 * at least one mistake in the use of punctuation was corrected (commas and dots must be placed after a parenthesis, not before);
 * I introduced the symbol used to refer to the Krull dimension of a ring, which was previously employed in the last section of the article without any previous mention;
 * I added some links to other pages which might be helpful for the reader (e.g. Zariski topology, finitely generated as an algebra instead of finitely generated as algebra, and so on);
 * I added a note to clarify why the height of a prime ideal is equal to the Krull dimension of the localised ring to that ideal and also a reference to its proof;
 * I slightly modified the closing sections by renaming Notes as References (which is more appropriate) and adding again the section Notes to contain remarks and clarifications.

For all these reasons, not only did my edit improve the readability of the article by using the same symbols consistently all over it, but also added new pertinent information (as required by MOS:FORMULA).

Please, reconsider your reversion and have a nice weekend. --Ale.rossi91 (talk) 21:15, 1 February 2020 (UTC)
 * Thank you for your effort for improving Wikipedia. You must not forget that Wikipeida is a collective work. It follows that it is important that other editors can check easily your edit, this is one of the reasons for avoiding large-scale formatting change, like yours. Another reason, is that, when such a change introduces errors (this is quite common), there are difficult to detect. There was long discussions between editors about the choice between html and latex. Both have advantages and drawbacks. The consensus is that latex is always preferred for displayed formulas and complicate inline formulas. However, for simple inline formulas, latex has drawbacks, mainly because of frequent (this depend on the browser and the zoom factor) horizontal misalignment, and different fontsize.
 * Therefore, for simple inline formulas, html is usually preferred. However, it is preferred with the use of the template math, but many articles such that this one have been written before the systematic use of this template. I recomment to use it, as it is easy to use it by slecting the formula and clicing on the corresponding button. So, when encontering Rr, transforming it in $Rr$ transforms the rendering from Rr to $Rr$, which is not very different fron the latex $$Rr.$$ (however, in the case of an equal sign in the formula you must add 1= just before the formula, such as $R = S$) for $R = S$).
 * I hope having convinced you. D.Lazard (talk) 21:57, 1 February 2020 (UTC)
 * Actually, you did not. Anyway, I shall list the small edits I intend to make (purged of the restyling, which seems to be your main concern) on Talk:Krull_dimension. I hope you will tell me which ones you agree on and if you believe it is better to make only one edit or many small edits so as to avoid the appearance of unintended mistakes. Here: Talk:Krull_dimension --Ale.rossi91 (talk) 23:09, 1 February 2020 (UTC)

Disambiguation link notification for March 22
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Hyperbolastic functions
I have declined the draft based on your comments. The author can resubmit it after providing more information on the practical application of these differential equations. Thank you for reviewing. I have forgotten all of the higher mathematics that I learned in college fifty years ago. I still remember first-year calculus, but I studied it in high school. Robert McClenon (talk) 19:23, 24 March 2020 (UTC)

Trig functions
Sorry your edit got caught up in my revert; I really had no opinion about it, but the other editor's been making a lot of bad changes, and it wouldn't let me just revert his. I'd put it back, but I wasn't totally sure if the subsequent revert changed any of the need for what you had intended. –Deacon Vorbis (carbon &bull; videos) 13:49, 31 March 2020 (UTC)


 * No problem: I had no clear opinion on the insertion on subsection hedings, and I have fixed them instead to revert them. But, finally, the revert is a better option. The move of one figure for avoiding conflict with the table is easy to redo. D.Lazard (talk) 13:57, 31 March 2020 (UTC)

Juan Branco
Hello, I'm trying to work on Juan Branco's page. Please wait for edits to be done before reverting and intervene on discussion page if disagreements arise. — Preceding unsigned comment added by Elahadji (talk • contribs) 11:39, 29 March 2020 (UTC)


 * Please refrain from starting an edit-war on an article that currently finds consensus. Re-reading your changes raises suspicion that you are not acting in good faith. If you have individual suggestions, you can mention them on the articles' talk-page and we will discuss them. XInolanIX (talk) 14:16, 29 March 2020 (UTC)
 * I have done so, and I don't consider this article to reach any consensual status nor to be by any means close to the expected objectivity. Please refrain from savagely reverting legitimate changes that neutralize a page and do not include any hagiographic, false or non-encyclopedic. I have suspicions that you do not act in good faith, as the article in its previous form was not. And being three persons agreeing on the matter does not change it at all. I have opened the discussion and wait for your contribution. Elahadji (talk) —Preceding undated comment added 17:19, 29 March 2020 (UTC)
 * Wikipedia rules are clear: "A bold change during an edit war should be an adaptive edit to discourage further warring and not to escalate it; it should never be another revert. Engaging in similar behavior by reverting a contribution during an edit war could be seen as disruptive and may garner sanctions. Never continue an edit war as an uninvolved party." XInolanIX and D.Lazard, refrain from savage reverts agaisnt constructive changes. Elahadji (talk) 17:39, 29 March 2020 (UTC) — Preceding unsigned comment added by Elahadji (talk • contribs)

FYI: He's trying to have me banned now. — Preceding unsigned comment added by XInolanIX (talk • contribs) 13:06, 1 April 2020 (UTC)

Please sign
You seem to have forgotten to sign here. I can add an unsigned template but far better for you to sign it. TIA Andrewa (talk) 04:10, 2 May 2020 (UTC)
 * Done. Thanks. D.Lazard (talk) 07:47, 2 May 2020 (UTC)

Common meanings vs. common nouns
The "common" in "common noun" is not the same meaning as "common" as in "common meaning". MOS:DABCOMMON allows for putting common meanings at the top. It has nothing to do with putting common nouns before proper nouns. If there's a topic that's not a primary topic but should be given special consideration, that needs to be discussed on the dab talk page. -- JHunterJ (talk) 13:36, 3 May 2020 (UTC)
 * MOS:DABCOMMON says explicitely: "In cases where a small number of main topics are significantly more likely to be the reader's target, several of the most common meanings may be placed at the top, with other meanings below". Here none of the proper names is a common meaning of the word "unknown", and each of the two common-noun meanings that are listed is much closer to refer to a primary topic than any proper name. D.Lazard (talk) 13:57, 3 May 2020 (UTC)
 * That is a possible consensus of the discussion that could occur. On the face of it, the mathematical unknown may be more familiar to you as a mathematician than to the average Wikipedia user. But regardless, it's important to understand that MOS:DABCOMMON has nothing to do with common noun vs. proper noun. Those are different English meanings of the word "common". -- JHunterJ (talk) 14:02, 3 May 2020 (UTC)

Natural numbers edit
I made the edit because of the upper case letter that seemed out of place in the text. Thanks for the remark saying that a pipe is not necessary. So I could have done with replacing the upper case letter with a lower case letter.Redav (talk) 18:11, 15 May 2020 (UTC)

TeX form of (x-a)^n
D.Lazard: The TeX spacing around + and - is meant to separate terms in an expression, such as in a Taylor series. However, x-a should be thought of as a single quantity, an increment $$\Delta x$$, not as a difference of terms $$x - a$$. It reads much clearer as $$(x{-}a)^n$$ than $$(x - a)^n$$.

As for the spaces around equal signs, \ = \, perhaps it does not read as nicely; however, the conceptual separation between the two sides of an equation is greater than that between terms on each side, so the space should also perhaps be greater. Magyar25 (talk) 20:12, 18 May 2020 (UTC)


 * In a Taylor series, $$x-a$$ is not a single quantity, as a Taylor series is a function of the variable $x$. For \ = \, if you think that the spaces around "=" are not sufficient, as this is not specific to this article, you must ask the question at WT:WPM for knowing whether there is a consensus about this. If there is a consensus, an error ticket must be open for fixing this at the latex implementation level. Doing this by hand on some articles has three bad side effects: 1/ It makes the source of formulas more difficult to read. 2/ It introduces inconsistencies between the articles you have edited and the other articles. 3/ A future change in latex implementation could have unpredictable effects that would be almost impossible to fix, if many articles are concerned.
 * In any case, do not do in the same edit a format change and a content change, as, if an other editor disagrees on one of your change, a partial revert may be time consuming. For the same reason, do not change several sections in the same edit, as this may make difficult to locate your edits for evaluating them. D.Lazard (talk) 07:25, 19 May 2020 (UTC)
 * I take your point about separating changes into reversible compartments. This particular change, {+} vs +, seems pretty harmless for Tex rendering: if {} were ignored, the formula would still display fine; though yes, it is cluttered in the source.
 * True, it's not a consensus point of view: I am trying to convince people to TeX this way, to better display their thinking to readers. Spacing is irrelevant to the logical content, but it can show heuristics, like phrasing in music. In $$f(a) + f'(a)(x - a) + \tfrac{f''(a)}{2}(x-a)^2$$, the terms in parentheses should not be the same distance apart as the main terms, because they form a unit conceptually, which is why we often replace x-a by a single variable h. The same with $$(k+1)!$$ vs $$(k{+}1)!$$, because k+1 is conceptually "the successor of k", not the sum of equally significant quantities k and 1.
 * I agree that the \ = \ change is pretty broad, and I would not want to force it on everyone, but let a consensus emerge from trying it out. You say: "you must ask the question at WT:WPM for knowing whether there is a consensus about this,... an error ticket must be open for fixing this..." Isn't this going too far toward an editorial committee, a gatekeeper of comme il faut? Isn't the spirit of Wikipedia to let everyone present their content to everyone, and let the majority decide? Magyar25 (talk) 16:49, 19 May 2020 (UTC)
 * Manual spacing around relations like the equal sign should almost be used.  Putting braces around operators similarly shouldn't.  –Deacon Vorbis (carbon &bull; videos) 17:00, 19 May 2020 (UTC)
 * I agree that the \ = \ change is pretty broad, and I would not want to force it on everyone, but let a consensus emerge from trying it out. You say: "you must ask the question at WT:WPM for knowing whether there is a consensus about this,... an error ticket must be open for fixing this..." Isn't this going too far toward an editorial committee, a gatekeeper of comme il faut? Isn't the spirit of Wikipedia to let everyone present their content to everyone, and let the majority decide? Magyar25 (talk) 16:49, 19 May 2020 (UTC)
 * Manual spacing around relations like the equal sign should almost be used.  Putting braces around operators similarly shouldn't.  –Deacon Vorbis (carbon &bull; videos) 17:00, 19 May 2020 (UTC)

Thank you
Thanks for being so civil with me at Talk:Turing_completeness. Jar354 (talk) 23:17, 19 May 2020 (UTC)

Length of a module
Hi D. Lazard, I see you added a tag in the pole order section claiming the Weierstrass factorization theorem should not be cited in this section. I don't think this is true, check out these notes https://faculty.etsu.edu/gardnerr/5510/notes/VII-5.pdf and these notes https://faculty.math.illinois.edu/~r-ash/CV/CV6.pdf. You can definitely extract out the order of poles and zeros using the factorization theorem. Wundzer (talk) 19:53, 26 May 2020 (UTC)
 * Apparently, you don't understant the point of my tag. However, as this is a discussion about the content of a specific article, it does not belong my talk page, but to Talk:Length of a module, where I'll give soon a detailed explanation of my tag. D.Lazard (talk) 08:23, 27 May 2020 (UTC)

root of unity. unexplained change of notation.
The section of the article uses the variable k for two different proposes. It even refers to the first introduced usage after introducing the second. For this reason I thought it'd be less confusing if a different letter m was used. I'm on mobile and wasn't sure how to explain the reason for the change to the article. StephenJohns00 (talk) 15:29, 11 June 2020 (UTC)
 * OK, you are right. I have restored your version. D.Lazard (talk) 16:40, 11 June 2020 (UTC)

Language
On your user page, you refer to a contributor as a crank. Is there a need for that? Kind regards, --Svennik (talk) 13:18, 16 June 2020 (UTC)

WRONG FORMULA
D.Lazard, You undid an edit I did on Summation page in the general formula
 * $$\sum_{i=0}^n i^p = \frac{(n+1)^{p+1}}{p+1} + \sum_{k=1}^p\frac{B_k}{p-k+1}{p\choose k}(n+1)^{p-k+1}$$

But this formula you insist on keeping is so wrong and I'm going to prove it.

Look at the original Faulhaber's formula which is:
 * $$ \sum_{k=1}^s k^{p}

= \frac{s^{p+1}}{p+1}+\frac{1}{2}s^p+\sum_{k=2}^p \frac{B_{k}}{k!}\dfrac{p!}{(p-k+1)!}s^{p-k+1}$$

PROOF:

\frac{s^{p+1}}{p+1}+\frac{1}{2}s^p+\sum_{k=2}^p \frac{B_{k}}{k!}\dfrac{p!}{(p-k+1)!}s^{p-k+1} =\frac{s^{p+1}}{p+1}+\sum_{k=1}^p \frac{B_{k}}{k!}\frac{p! \cdot s^{p-k+1}}{(p-k+1)!} =\frac{s^{p+1}}{p+1}+\sum_{k=1}^p \frac{B_{k}}{k!}\frac{p! \cdot s^{p-k+1}}{(p-k+1)\cdot(p-k)!} $$



=\frac{s^{p+1}}{p+1}+\sum_{k=1}^p \frac{p! }{(p-k)!\cdot k!}\frac{ B_{k}\cdot s^{p-k+1}}{(p-k+1)} =\frac{s^{p+1}}{p+1}+\sum_{k=1}^p {p\choose k}\frac{ B_{k}\cdot s^{p-k+1}}{p-k+1} =\frac{s^{p+1}}{p+1} + \sum_{k=1}^p\frac{B_k}{p-k+1}{p\choose k}s^{p-k+1} $$

We therefore have

\frac{s^{p+1}}{p+1} + \sum_{k=1}^p\frac{B_k}{p-k+1}{p\choose k}s^{p-k+1} = \sum_{k=1}^s k^{p} $$

Replacing "s" with "n+1" (s=n+1), it is:



\frac{(n+1)^{p+1}}{p+1} + \sum_{k=1}^p\frac{B_k}{p-k+1}{p\choose k}(n+1)^{p-k+1} = \sum_{k=1}^{n+1} k^{p} $$



\frac{(n+1)^{p+1}}{p+1} + \sum_{k=1}^p\frac{B_k}{p-k+1}{p\choose k}(n+1)^{p-k+1} \neq \sum_{i=0}^n i^p $$

Note: Please, if you don't know anything about mathematics, let the people who do know do the math.

Atte:Juandres106 (talk • contribs) 08:39, 18 June 2020 (UTC)


 * Your formula was this: $$\sum_{k=1}^n k^p = \frac{n^{p + 1}}{p + 1} + \sum_{k=1}^{p} \frac{n^{- k + p + 1} B_{k} {\binom{p}{k}}}{- k + p + 1}$$. It should actually be this: $$\sum_{k=1}^n k^p = \frac{n^{p + 1}}{p + 1} + \sum_{k=1}^{p+1} \frac{n^{- k + p + 1} B_{k} {\binom{p}{k}}}{- k + p + 1}$$. I checked in Sympy. --Svennik (talk) 12:39, 18 June 2020 (UTC)
 * Juandres106 I checked the original formula numerically. It actually works, unlike your substitute. --Svennik (talk) 12:46, 18 June 2020 (UTC)
 * 's formula cannot be correct as involving a division by zero in the term $$k=p+1.$$ 's formula is doubtful as it seems to have failed a Sympy verification. However both formulas are prettier than the older one (it is not mine), as producing a polynomial in $n$ rather than in $n + 1$. Nevertheless, as none formula is supported by a published source (see WP:Reliable sources), I'll restore the older stable formula, tagged with citation needed. Please, do not change the formula without providing a reliable source. D.Lazard (talk) 13:38, 18 June 2020 (UTC)
 * The correct version of his formula is actually $$\sum_{k=1}^{n} k^p = \frac{(n+1)^{p + 1}}{p + 1} + \sum_{k=1}^{p} \frac{(n+1)^{- k + p + 1} B_{k} {\binom{p}{k}}}{- k + p + 1}$$. Meaning that his $$n$$ is off by one, not his $$p$$. --Svennik (talk) 14:03, 18 June 2020 (UTC)
 * I made some further edits to the formula. --Svennik (talk) 14:08, 18 June 2020 (UTC)

Svennik what are you talking about? Why should the upper index be p+1? Did you see the proof I did? You're so confused. Juandres106 (talk) 13:50, 18 June 2020 (UTC)
 * Juandres106 I don't care about your "proof". --Svennik (talk) 14:04, 18 June 2020 (UTC)
 * This page is not suited for discussing a specific article. If you continue this discussion, please do it on the talk page of the article. I'll immediately delete any post here that belongs to Talk:Summation. D.Lazard (talk) 14:06, 18 June 2020 (UTC)

Please check this edit I made
Not sure on one of these changes and need your expertise. Thanks. --LilHelpa (talk) 18:36, 10 July 2020 (UTC)
 * Thanks for fixing my typos. "Rig" was not a typo. I have added a link. Also, one of my sentences was nonsensical, and not fixed by your edits. I have fixed it, although I am not sure that this is exactly what I wanted to say. D.Lazard (talk) 20:05, 10 July 2020 (UTC)
 * Sorry about the Rig. Thanks for your work here. I usually say that first. --LilHelpa (talk) 23:08, 10 July 2020 (UTC)

Linear differential equations
Since you contributed very significantly to the article Linear differential equation in the past few years, I invite you to answer the question that I have just asked on its talk page.

Thank you/Merci. J.P. Martin-Flatin (talk) 11:31, 13 July 2020 (UTC)

Differential calculus article edit revert
Hello. I saw that you reverted my edit to the differential calculus article because it 'does not improve the article'. Could you please clarify what you mean by this? TentativeTypist (talk) 15:22, 22 July 2020 (UTC)
 * Your edit was done in the lead. The purprose of a lead is not for providing technical details. It for presenting the basic ideas and the context. The basic idea of calculus is not that continuous functions have antiderivative. It is that, in the whole, differentiation and integration are inverse processes. The fundamental theorem of calculus is the technical result that establishes this relationship. Therefore the previous formulation is much better for the lead.
 * Similarly the fact that differentiation provides the best linear approximation of a function is fundamental in all sciences. Therefore this belongs to the lead.
 * Also, the replacement of "physics" by "mechanics" is formally correct; "physics" was also correct, as mecanics is a subarea of physics. "Physics" must be prefered to "mechanics", because the latter suggests wrongly that this is specific to mechanics, while there are similar uses in all physics.
 * If you disagree, please, stop the discussion here, and open another one in the talk page of the article, in order that other editors may give their opinion (see WP:BRD). D.Lazard (talk) 16:44, 22 July 2020 (UTC)

Quaternion notation
I've re-done the prior mods that you reverted, without the objected-to mixed bold and italic for quaternions. You were right to complain; I should have removed that when I failed to figure out how to combine bold and italic in TeX.


 * The present edit of the article uses standard vector notation: All scalars are non-bold italics (so all quaternion components, angles, scalar parts, and norms); all quaternions (other than scalars) are bold. The same as standard (non-arrow) vector notation, even though this is not $ℝ³$.


 * I distinguished the complex unit, $i$ from the quaternion unit-vector i where it's used.


 * I did not put in scalar unit vectors as 1, but left it there where it was already present. (At the top of the article it's 1, at the bottom it's 1.)


 * The other changes involve encapsulating the unicode BBB characters ℝ, ℂ, and ℍ inside $·$ (hence $ℝ$, $ℂ$, and $ℍ$) to cure rendering problems when embedded in regular text. My browser presents the first set of letters as small-caps-sized.

That last change might also possibly reduce some problems for browsers with older fonts; no guarantees, but using the mathematics-rendering font might relieve some problems for readers, if they've already managed to accomodate the wikipedia's math rendering. Astro-Tom-ical (talk) 08:22, 30 July 2020 (UTC)
 * Boldface is commonly used for vectors, but it is not a standard in mathematics. In any case, as non-bold is acceptable for quaternions, MOS:VAR clearly states that this must not be changed without a consensus on the talk page.
 * $ℝ³$ is forbidden by MOS:SUPERSCRIPT.
 * I would agree to encapsulate unicode blackboard bold into math, but it is an error to do this when this appears in a formula that is already inside math.
 * There are many other changes in your edit. Few are useful. Many are non useful and fall under MOS:VAR (such that changing the name of a variable or replacing * by $$) . Some are simply wong, such as having a template math around a part of a formula, or capitalizing after a colon. D.Lazard (talk) 09:54, 30 July 2020 (UTC)

5 August: vandalism and edit-warring
Please could you stop edit-warring and vandalism. As far as I can tell, you have not actually contributed very much content to wikipedia, except for gnoming. You have made minimal attempts to diccuss sources on "Differential geometry of surfaces". Without consensus you have revert warred, and edit-warred in a WP:BATTLEGROUND attitude to prevent any reasonable editing occuring. That is normally called WP:NOTHERE and could result in a block. Since I need the material on 2 variable calculus, it will stay in the article. If you continue edit-warring, it is likely that you will be blocked. Similarly If you continue making belittling comments liable to create discord amongst those trying to create content. If need be, you might be reported at WP:ANI. Mathsci (talk) 11:35, 5 August 2020 (UTC)
 * My revert is based on a clear WP:CONSENSUS (in Wikipedia, a consensus does not requires unanimity) on the talk page, were four established editors of mathematics agree that this section must be removed, and justify their opinion with clear arguments that are expressed in various way. On the other hand you are alone for desiring to keep the section, and the given reasons are irrelevant, mostly based on your project for the article. I must recall that per WP:OWN, you do not own this article, and thus your intensions are irrelevant.
 * So it is you who engaged this edit war. As it is again a consensus, this is WP:disruptive editing and could lead to a block. D.Lazard (talk) 12:44, 5 August 2020 (UTC)

5 August
There is currently a discussion at Administrators' noticeboard/Incidents regarding an issue with which you may have been involved. Thank you.--Mathsci (talk) 15:28, 5 August 2020 (UTC)

Reversion of edit in Nth root
Hi – you undid my edit to Nth root, with the edit comment "undefined lexicographical order". Why is the lexicographical order undefined? If it wasn't clear that this refers to the lexicographical order on $$\mathbb C$$ viewed as $$\mathbb R^2$$, we could make that explicit. Joriki (talk) 20:35, 16 August 2020 (UTC)
 * Yes one can define a lexicographical order on the complex numbers, but this should be done in Complex number, if there are reliable sources that define it. Otherwise this would be WP:Original research. In this article it is useless, and possibly confusing for some readers, to indroduce the technical concept of lexicographical order, when the preceding definition is more elementary and perfectly clear. IMO, using a sophisticated terminology for describing a simple thing like that is a kind of pedantryD.Lazard (talk) 20:49, 16 August 2020 (UTC)

August 2020
This is just to inform you that, contrary to your impressions, there has been no copy-vio. The passages were all carefully prepared as paraphrase-summaries. They were not copy-pasted contrary to your allegations You have not made the slightest attempt to check the paraphrase-summaries with the original. This morning on your user talk page, with Gumshoe2, you planned to find way of reverting any edits to symmetry of second derivatives. That has been documented with diffs on User talk:Salix alba. I am requesting that a former arbitrator helps me deal with the difficulties you have created. You have not been acting in good faith. Mathsci (talk) 20:13, 19 August 2020 (UTC)

Notice of noticeboard discussion
There is currently a discussion at Administrators' noticeboard regarding an issue with which you may have been involved. Thank you.. At the moment I'd like this to focus more on a possible process to follow rather than the actual dispute. --Salix alba (talk): 16:05, 22 August 2020 (UTC)

On some properties listed in the Resultant article
Section moved to Talk:Resultant. D.Lazard (talk) 08:24, 26 August 2020 (UTC)

Script to show shortdescs of all pages in a category
Hi. I know you have been adding short descriptions to math article, as have I, and I want to call your attention to Wikipedia_talk:WikiProject_Short_descriptions. I requested this script and SD0001 was kind enough to write it. In addition to aiding in editing short descriptions, I think it may have value in making math categories much more useful, allowing readers to quickly see what theorems named after people are about. Best,--agr (talk) 21:50, 27 August 2020 (UTC)

Symmetry of second derivatives
I really appreciated your contributions at the Differential Geometry of Surfaces page and on the ANI thread, I'd have felt a little less sane without them. I recently came across the page Symmetry of second derivatives, which mathsci has also edited quite a bit recently. I think it's pretty clear that the page was better before their edits (aside from the history section, although it seems to be, to some extent, plagiarized from its source - although I don't know the wiki standards for this). The main proof is essentially repeated twice, the second time in a slightly different language, and there is a seemingly inappropriate detour into the proof of Fubini's theorem. I absolutely do not want to get into more edit conversations with mathsci, and I don't want to clutter WikiProject:Math with what might look like personal bickering. Is there any way to flag this page in some way as needing certain specific edits? I'm finding it sort of difficult to understand all the wikipedia procedures Gumshoe2 (talk) 06:20, 19 August 2020 (UTC)
 * For your problem with Symmetry of second derivatives, the main guideline is WP:BRD, specially WP:BRDREVERT. That is, you boldly revert (or partially revert) to an older version, and explain in the talk page of the article the reasons of this revert, and why the reversion makes the article better. In this case, it is certainly better to explain the revert on the talk page before proceeding, because, if Mathsci start discussing in his usual way, this will allow to not answer to his out-of-subject comments. If he tries to restore the reverted version without a consensus on the talk page, and starts edit warring, then you can hope the help from other watchers of the talk page. I have put this page on my watch list. So, in case of an edit war, WP:3RR will be easier to invoke.
 * History section: I do not see plagiarism here. However, the older version is much better. In fact, the newer version contains the older version as a first paragraph. Its second paragraph consists essentially in a pedagogical advice that is misplaced here, and seems original research. The remainder of the newer version is a repetition with more details of the first paragraph. It contains sentences that do not belong here, such as the mention in the text of Cantor's historical work (it could be in the references, if used in the text) and the mention without attribution of a 'stage of "primitive" investigations'. It could be useful to expand the first paragraph by merging in it some of the content of the end of the newer section, but this seems of a relatively minor importance, and can be differed until the intended reversion will be stabilized. D.Lazard (talk) 09:47, 19 August 2020 (UTC)
 * Thanks for your help. My comment on plagiarism is based, for instance, on the following comparison:
 * "Six years after Lindelöf, Schwarz published the first satisfactory proof, thus starting the next stage of investigations. Mathematicians tried to relax some of the assumptions of Schwarz. After an unsuccessful attempt by Thomae in 1875, the Italian mathematician Dini made an improved on Schwarz by introducing the more general "Dini-Schwarz conditions". Following another fruitless effort by Harnack in 1881, Jordan in 1882 was able to make headway. Assuming less than Dini, he published in 1883 the proof that can now be found in most text books. Along with this popular account, there are other versions by Laurent (1885), Peano (1889 and 1893), J. Edwards (1892), P. Haag (1893), J. K. Whittemore (1898), Vivanti (1899), and Pierpont (1905). Some of these expositions were perfect, some not, but essentially apart from changing some points of view in a minor way, Jordan's proof was adopted."


 * vs.
 * "Six years later H. A. Schwarz [14] gave the first satisfactory proof, this inaugurating the second period of investigation. A valid proof having been given, his successors bent their efforts towards formulating proofs based on less restrictive hypotheses than those of Schwarz. After an abortive attempt by J. Thomae [15] in 1875, the Italian mathematician U. Dini [16] gave in 1877 the set of conditions familiarly known as the Dini-Schwarz conditions. Following an unsuccessful effort by A. Harnack [17] in 1881, C. Jordan [18] in 1882 made the next advance. Postulating a set of conditions somewhat less restrictive than those of Dini, he put forward the proof found in the majority of texts published since that year. Subsequent to this popular proof appeared others by H. Laurent [19] in 1885, G. Peano [20] [21] [*] in 1889 and 1893, J. Edwards [22] in 1892, P. Haag [23] in 1893, J. K. Whittemore [24] in 1898, G. Vivanti [25] in 1899, and J. Pierpont [26] in 1905. Of these, some were perfect, some imperfect, but none were essentially new: most of them differed from previously published proofs only in minor points of analysis."


 * The pedagogical advice you mention also appears: e.g.
 * "Most advanced calculus texts contain sufficient conditions and proof for the equality of second mixed partial derivatives. Hence this is something that should interest those involved in teaching and learning that part of analysis."


 * vs.
 * "Since a set of sufficient conditions and proof for the same are generally given in most advanced calculus texts, the student of analysis is usually familiar with at least one proof. Accordingly, a brief account of the mathematical history associated with this bit of analysis should not be without interest to the serious student or teacher."


 * It seems that his additions to the section transplant the entire source material in this way. I believe this would be quite bad in a student essay; as far as I can see, Plagiarism doesn't explain standards for this kind of extensive copy-paste-modify. Gumshoe2 (talk) 16:05, 19 August 2020 (UTC)
 * This falls under the policy WP:COPYVIO, which states "Even inserting text copied with some changes can be a copyright violation if there is substantial linguistic similarity in creative language or sentence structure". So, I'll immediately remove these paragraphs of the history section. I'll leave to you the decision of reverting the other Mathsci's additions. D.Lazard (talk) 16:41, 19 August 2020 (UTC)
 * I see, that makes sense. Thanks again Gumshoe2 (talk) 16:43, 19 August 2020 (UTC)

FYI, I was the one who originally added the history section here: https://en.wikipedia.org/w/index.php?title=Symmetry_of_second_derivatives&oldid=776130344. I had tried to summarize the most relevant parts of the referenced article at that time, and I see that over the years people have gradually added more paraphrasing/copying from the article itself. Anyway, not a problem. PatrickR2 (talk) 06:32, 29 August 2020 (UTC)

Quantic - "Unsourced terminology"
Click on the Wiktionary link!— Pingkudimmi 14:38, 5 September 2020 (UTC)
 * Wiktionary is not a source, but sources are provided there. So, I have added the term in Homogeneous polynomial and restored the link to this article. Please, do not add an item to a disambiguation page, when the term does not appear in the linked article. D.Lazard (talk) 15:04, 5 September 2020 (UTC)


 * Thanks, that seems about right.— Pingkudimmi 21:56, 5 September 2020 (UTC)

"Each problem has a singular complexity"
Are you certain about that? Joefromrandb (talk) 17:17, 21 September 2020 (UTC)

Oh shit. Now I understand. I wasn't reading carefully enough. Thanks for catching that. Joefromrandb (talk) 17:22, 21 September 2020 (UTC)

On Improving The Wikipedia Monomial Page
Howdy! I noticed you reverted my edit to the wiki page on Monomial, and as I'm fairly new to this I'll defer to you on wording there. I would like to see the opening paragraph improved, however, as its currently very hard for beginners to understand, and a large proportion of people looking up "monomial" on wikipedia are coming from an elementary mathematical background (most viewers are probably grade-schoolers trying to figure out what their textbook is talking about, at least from my personal experience). As such, it seems imperative that its opening description be relatively easy to understand. the opening sentence defines a monomial as being "a polynomial with only one term," but that sentence is rather useless for those not already familiar with the subject, as the definition of "term" isn't mentioned or linked to. Neither is "term" defined clearly in the Polynomial page, and its definition can only be found on wikipedia under Term (logic), and quite far down the page at that. In my opinion, it seems worth giving a short informal description at the beginning of the page, for non-experts in the topic. Additionally, the two definitions given after the opening sentence are quite convoluted, and took me a few minutes to understand what it was saying, despite knowing all the terms involved.

If you'd be able to help at all in cleaning up this page, I'd really appreciate it.

Thanks,

Yitz (talk) 21:19, 24 September 2020 (UTC)
 * , I have linked "term" to an elementary definition. By the way I have also linked this definition in the hatnote of Term (logic). Thus it is now easier to find it. I have also added an example just after the first sentence.
 * For improving the article further, I suggest to cut the first definition after the newly added example, to reduce the second definition to its first sentence, and to move the removed sentences into the section "Comparison of the two definition", which should be restructured and renamed "Detailed definitions". I'll not do this myself. Maybe you can do it.
 * Otherwise, I do not see how improving the lead. D.Lazard (talk) 09:24, 25 September 2020 (UTC)
 * Otherwise, I do not see how improving the lead. D.Lazard (talk) 09:24, 25 September 2020 (UTC)
 * Otherwise, I do not see how improving the lead. D.Lazard (talk) 09:24, 25 September 2020 (UTC)

Projective coordinates
It never ceases to amaze me the meddling of editors who lack domain knowledge for the most trivial shit on Wikipedia... Why would you waste other people's time with https://en.wikipedia.org/w/index.php?title=Homogeneous_coordinates&oldid=prev&diff=981301091? Is this really the sword you want to fall on?

Projective coordinates are a critical component for constant-time implementations of elliptic curve cryptography. Using projective coordinates, the identity element is nicely handled by z=0. That property means branches based on identity elements can be removed. Nearly every major C/C++ crypto library uses projective coordinates for add, double and Montgomery mulipliers to ensure constant-time-ness. The libraries include Botan, Crypto++, OpenSSL and GnuPG. See, for example, Complete addition formulas for prime order elliptic curves.

I'm not going to fix your mistake. You should revert your edit. Or, leave it broke. I don't give a shit. The article can stay incomplete, and you can own it.

Jeffrey Walton (talk) 21:59, 2 October 2020 (UTC)

Re: "Edit warring"
Regarding this change, I believe you are confusing me with another unregistered user. It seems I made my edit at an unfortunate time. Please re-read my edit, as I don't think it contains anything objectionable, and undo your undo if you agree. I haven't changed anything myself to avoid further misunderstanding. Thanks. --213.149.61.95 (talk) 12:14, 14 October 2020 (UTC)
 * Sorry, I have self-reverted my erroneous revert. About your edit, if Wikipedia would be a forum, your edit would not contain anything objectionable. But Wikipedia is not a forum, and edits of Wikipedia must comply with Wikipedia policies and guidelines, which is definitely not the case of your edit. D.Lazard (talk) 12:39, 14 October 2020 (UTC)
 * Sorry, I'm not sure I understand. Are you saying my edit doesn't comply with Wikipedia's policies and guidelines? And if my edit is harmful, why did you reinstate it? I wouldn't mind having my changes reverted if they were bad, of course, but I don't see what was wrong with my edit. I just fixed the messy formatting. --213.149.61.95 (talk) 13:05, 14 October 2020 (UTC)

Missing cite in Affine space
You added a short reference to "Hartshorne" but no such source is listed in bibliography. Can you please add? Also, suggest installing a script to highlight such errors in the future. All you need to do is copy and paste importScript('User:Svick/HarvErrors.js'); // Backlink: User:Svick/HarvErrors.js to your common.js page. Thanks, Renata (talk) 03:09, 19 October 2020 (UTC)
 * ✅ D.Lazard (talk) 09:29, 19 October 2020 (UTC)

Model theory
Um, I want to avoid a violent argument, so I am not sure how to phrase this. Have you actually read Wilifred Hodges book called "Model Theory"? Or maybe some other book on the topic? I have, and also a few others on proof theory. Now, this does not make me an expert, but it does make me question your recent edits to the intro to the article on model theory. What, exactly, makes you say that "its not about model theory"? Hodges himself says stuff about universal algebra in the preface or in chapter one or something like that. And yes, I've also read part-way into Paul Cohen's book on universal algebra, so it does not seem as off topic as you claim. I've also read more than a few books on algebraic geometry, so I also don't see anything wrong with the statement that "model theory = algebraic geometry - fields", which strikes me as a rather clever observation. So, again .. are you sure you want to make those edits? What is it in there that is so objectionable, or that cannot be found in this-or-such chapter of a book on model theory? (oh, and BTW, it would be best to have this conversation at Talk:Model theory rather than having it here; I just don't know how else to ping you. ) 67.198.37.16 (talk) 05:06, 23 October 2020 (UTC)


 * BTW, It's also interdisciplinary. If you look at satisfiability modulo theories aka SMT, the "theories" are exactly those things of model theory. SMT solvers are commonly used for computer chip fabrication and computer chip verification, and if you dig into engineering texts on quality control, they will typically have an intro chapter that recapitulates model theory in more-or-less exactly the same way that Hodges describes it in his books. I kid you not; you can do some google searches for SMT solvers and silicon verification testing, and you will find these texts. Yes, I found it mind-blowing when I stumbled over it in the early 2000's, but the trade rags actually claim that it was a bit of a break-through that upset the fortunes of more than a few companies in the verification industry. 67.198.37.16 (talk) 05:25, 23 October 2020 (UTC)


 * And you also erased the stuff about semantic and syntactic duality; but this appears in the chapter-one of books on proof theory, where they seem to have this obligatory sentence that says "if model theory is the sacred, then proof theory is the profane." The guys who write those books seem to like to say that, and, from what I can tell its partly about pecking order in math departments, and its partly about the syntactic vs semnatic duality in all the various theorems. 67.198.37.16 (talk) 05:41, 23 October 2020 (UTC)


 * Errr, well, OK, I actually looked at the article more carefully, and it does seem to be ... ugly and in need of ... a (major!) rewrite ... I assume that there are other articles that explain basic terminology like "what is a model" and "what is a theory" and "what is a language", "what is an interpretation", etc. But I have not looked. 67.198.37.16 (talk) 05:48, 23 October 2020 (UTC)
 * This discussion should be placed in the talk page of the article. Neverthess, it seems that you misinterpreted my comment in the tag. I never wrote "its not about model theory". I wrote "its not specifically about model theory". This means that a large part of the content is about theories that have been developped independently of model theory, that they are probably related to model theory, but the way they are presented do not explain their relations with model theory. D.Lazard (talk) 09:42, 23 October 2020 (UTC)

Tuple(s)
A tuple is an ordered list, tuples are ordered lists not specifically >permutations without repetitions<. >permutations without repetitions< refers to the cardinality of the different ways of ordering the elements of a set so it is an scalar number, not a set. Also there is not >permutation with out repetitions< as you will need at least 2 DIFFERENT members to count.Permutation Orendona (talk) 10:36, 31 October 2020 (UTC)  — Preceding unsigned comment added by Orendona (talk • contribs) 10:33, 31 October 2020 (UTC)
 * This seems to be about the article Permutation. So, this is misplaced here, and should be posted on Talk:Permutation.
 * By the way this seems to be about a section that I never edited before your post. I cannot understand why you post here.
 * Also, I see that you started WP:edit warring by reimplementing an edit that was reverted by another user. So I have reverted you again, because your formulation is non-sensical. D.Lazard (talk) 12:28, 31 October 2020 (UTC)

Non sensical is what it is stated. Tuples are ordered lists. Permutations without repetitions is a scalar number. Orendona (talk)

Bernoulli numbers in series representation of hyperbolic functions
Hi, ! Could you, please, elaborate on the comment you gave in your revert (Special:Diff/986534862) in Hyperbolic functions?

As far as I can see in the Bernoulli number article, there actually are two definitions – but they differ in the sign of the $$B_1$$ term, and the modification by (Special:Diff/986524749) involves $$B_0$$ which is $$1$$ in both definitions. So the choice of a specific definition should not affect the result of summation.

What did I miss, then? What is the actual importance of leaving the first term outside the $$\Sigma$$ sum? --CiaPan (talk) 09:49, 4 November 2020 (UTC) PS. I pinged User:Parcy Taxel, whose edit you reverted, so please reply here to keep the thread in one place. CiaPan (talk)
 * Ok, I reverted too fastly. I have undone my revert. By the way, I have copy-edited the section, for fixing some poor formulation and errors (two of the series are not Taylor series, but Laurent series), it is not because the series has only terms of even degrees that the function is even, but it is the contrary; the inequalities after the series require to be explained; etc.). D.Lazard (talk) 11:01, 4 November 2020 (UTC)


 * Thank you for your prompt reply. Happy editing! CiaPan (talk) 11:09, 4 November 2020 (UTC)

I’m a tad rusty at math, except a couple specialties
Hi could you check my edit at quadratic form. I changed it to saying a quad form is definite if it is only zero when all variables are zero, because I can’t see how it could never be zero as in previous version. Thanks. Rich (talk) 19:00, 5 November 2020 (UTC)
 * Such a post should be placed on the talk page of the edited article. Posting here had the consequences that another editor reverted you without knowing of your post, and I had to provide a long edit summary for explaning the reason of my revert. This edit summary may also be viewed as a reply to your above post. D.Lazard (talk) 20:49, 5 November 2020 (UTC)

Partial fields
I saw your re-edit and I imagine that you have not red the references. I usually do a reasonable amount of research before editing and expecially before removing, and in the case of removal I move it to the talk to open a fair discussion. Partial fields are well established. The article or the blog may not be the best reference to them but if you have a prob with the references you can fix them yourself reading something about it https://www.sciencedirect.com/science/article/pii/S019688589690010X , second what is the definition of misplaced ? and relegated to matroids ? is just an extra type of division ring so what ? Can you kindly fix it back ? — Preceding unsigned comment added by Flyredeagle (talk • contribs) 16:38, 8 November 2020 (UTC)
 * Please, sign your posts in talk pages with 4 tildes ( ~ ).
 * There are two problem with your edits: Is it relevant for the article Field? Is it relevant for Wikipedia.
 * Relevance to Field: A partial field is not a field. Moreover it is unlikely that a reader interested in fields is also interested in partial fields. So, there is no reason to discuss partial fields in Field. At most, an item in section "See also" could be useful (if an article of this name would exist), for people confused by the name similarity. On the other hand, as partial fields seem to have been introduced for the study of matroids, mentioning partial fields in Matroid representation would make sense if the theory of partial fields would be sufficiently notable for Wikipedia. This is what I had in mind when saying that your edit was misplaced.
 * Relevance to Wikipedia. Every information that is added to Wikipedia must be notable (see WP:Notability). In case of mathematical concepts this means that some WP:secondary sources discuss the concept. By "secondary sources", Wikipedia means reliably published sources whose authors are independent from the authors of the concept. You have not provided such a secondary source. So, until that one will be provided (if some exist, which is unclear), partial fields have not their place in Wikipedia. D.Lazard (talk) 17:23, 8 November 2020 (UTC)

I agree that a battle to defend partial fields is a lost battle, because I did not found independent tertiary sources, and I am no expert there, but I still don't understand the process of censorship:

This is a primary source for the definition of partial fields: https://www.sciencedirect.com/science/article/pii/S019688589690010X

This is a secondary source: https://arxiv.org/abs/1106.3088

which actually if you read well it states: Adv. in Appl. Math. 50 (2013), no. 1, 228-242 and if you search it, it goes to: https://www.sciencedirect.com/science/article/pii/S0196885812000863

Now secondary sources must not be independent according to the policy above, to me they look independent given is two publications with a distance of 20 years one group in NL and one group in New Zealand.

Pure Math
I know it was a revenge and let's bury it, but we risk that we justify everything with this way of using policies.

This includes the non reliable sources on youtube (namely you censored a field medal and a nobel prize). You censored also quite a bunch of Mathematicians on the criticism of Bourbaki page. Plus you censored a set of reliable sources on the same topics also.

Can we stop this way of censoring things ? Especially can we stop the approach "Don't touch my page(s) ?

I think a lot of wikipedia censors go in this mode quickly assigning the wrong labels to genuine contributions. I believe instead that there should pro-active cross editing to reuse the contributions of other people.

I understood you have quite an academic background, and maybe in the blink of an eye you have an opinion, but I think that too much oppressive censorship, and too much overcontrol on what is allowed in a page or not, is discouraging genuine work and contributions from other people.

Finally a criticism section is unilateral isn't it ? Flyredeagle (talk) 19:24, 8 November 2020 (UTC)
 * There is no censorship in my reverts. Wikipedia is not a blog where everybody write what he want. It is a collaborative encyclopedy. See WP:The five pillars of Wikipedia and WP:What Wikipedia is not for a better understanding of what this mean. It is clear that it is frequent that editors disagree on some points in the article. The standard process for resolving this sort of dispute is well described in WP:BRD. You will see there that reverting is not censorship.
 * About pure mathematics, you may also find useful to read carefully the lead of the article, and think how "criticism" may apply to a such a concept. In your edit, it is even unclear whether you apply "critiscism" to the practice of mathematicians who qualify themselve as pure mathematicians or to the usefulness of pure mathematics, or even to the usefulness of mathematics in general. Maybe you apply that to some way of teaching mathematics. In any case, your presentation is definitively confusing and misleading. D.Lazard (talk) 21:39, 8 November 2020 (UTC)

Unicode block article names
Hello there. I noticed you moved "Mathematical Operators" to "Mathematical Operators (Unicode)". The other Unicode block articles are named either "Block Name" or "Block Name (Unicode block)". For example, Aegean Numbers (Unicode block). I recommend you rename "Mathematical Operators (Unicode)" to "Mathematical Operators (Unicode block)". This will keep the naming pattern intact and reduce confusion between the article about the Unicode block Mathematical Operators and the more general article listing Mathematical operators and symbols in Unicode. Thank you. DRMcCreedy (talk) 16:48, 15 November 2020 (UTC)
 * OK, I'll try to do this. D.Lazard (talk) 16:51, 15 November 2020 (UTC)

May not equal (meaning)
Where is the ambiguity that you claimed.?

(a) T (may not) equal f

(It may be that the following statement is not true (false): T=f)

(b) T may (not equal) f

(It may be that the following statement is true: T≠f)

What is the difference.? LMSchmitt 11:59, 23 November 2020 (UTC)
 * This can also be read "it may not be that the following statement is true: T=f", which is completely different. D.Lazard (talk) 13:41, 23 November 2020 (UTC)
 * OK. Thank you very much. I looked at it many times, and didn't get it.

Procédures en diffamation
Bonjour, pour information, et après vous avoir prévenu ainsi que l'utilisateur que vous savez de la nature diffamatoire des informations que vous tentiez de faire publier, je prépare des poursuites pénales à votre encontre, via une plainte avec constitution de partie civile auprès du doyen des juges d'instruction. Wikimedia a été mis au courant, afin d'éviter toute mal interprétation et respecter les règles de l'encyclopédie. Ces procédures permettent l'identification des tenants des comptes concernés.

Bien cordialement,

Juan Branco — Preceding unsigned comment added by 2A01:CB04:B16:B300:35FB:2FAC:387D:ED62 (talk) 18:45, 24 November 2020 (UTC)

Hi
Hey why are you reverting my edit when it is legit :-( on https://en.m.wikipedia.org/wiki/Equation#:~:text=In%20mathematics%2C%20an%20equation%20is,the%20equals%20sign%20%22%3D%22.&text=The%20expressions%20on%20the%20two,hand%20side%22%20of%20the%20equation. Prakharblue123 (talk) 16:58, 27 November 2020 (UTC)

I was with anonymous account Prakharblue123 (talk) 17:00, 27 November 2020 (UTC)

Augustin-Louis Cauchy
Hello D. Lazard, I deleted the evidence on Augustin-Louis Cauchy because of the message here, as well as all the other evidence that I have made over the past few days. I'm sorry. greeting --Nixnubix (talk) 15:47, 13 December 2020 (UTC)
 * ADDENDUM: Maybe you should also have a look here. --Nixnubix (talk) 15:51, 13 December 2020 (UTC)

Enumeration reducibility
Greetings,

I have recently created a new article, Enumeration reducibility. You commented on my proposition on the talk page for WP:WPM and asked for a draft, so here it is.

I request a proofread and any tips you may have as an experienced editor. Thanks. paraorthomodular (talk) 03:50, 17 December 2020 (UTC)

Enwiki policy
In Revert by user:D.Lazard on 2020-12-19 you give the impression that you are kind of validator who looks after recent edits whether to accept them or not. (I did not know of such an institution in enwiki. Would you pls show me some written material about this matter? We have it in dewiki, and ours looks much more institutionalized, it is e.g. visible at the edits themselves.) If there is such an institution in enwiki, I certainly so not want to make your task more difficult than necessary. –Nomen4Omen (talk) 18:55, 20 December 2020 (UTC)
 * Wikipedia is a collective work. So every user is a kind of validator of other's edits. Watchlists are here for allowing users to know the modifications of the articles that they are interested in. Edit summaries are aimed to allow users to know the nature of the changes appearing in their watchlist without spending too much time for that. When two editors disagree on an edit, WP:BRD explains in details the standard way for resolving the dispute and avoiding WP:edit warring. In this specific case, if your second edit would have an edit summary like "better use of colors" there would be no problem. Without an edit summary, your edit looked like the start of an edit war (revert of a revert). It is only because the change of the byte length of the article was not the same that I understood that it was not the case. See also WP:FIES. D.Lazard (talk) 10:41, 21 December 2020 (UTC)


 * OK, what I understand: it is not institutionally that you revert. This is an important insight.
 * My second edit had a "see talk", and this tried to pull your attention to "the color changes". In my opinion this is not worse than your "better use of colors". (In my opinion, this does not match well with your remark "You do not explain here and in you edit summaries why you think that your edits improve the articles.")
 * In my opinion the previous colors were misleading and the new colors are a real improvement — be it an extremely small one — and not only a "cosmetic change".
 * Finally: I am NOT totally "unhappy with the time spent because of your lack of explanations".
 * –Nomen4Omen (talk) 15:20, 21 December 2020 (UTC)

Jan 2021
Hello. I read your edit summary asking who agrees with me, it was the editor who initially reverted me. Should've made that more clear. GOLDIEM J (talk) 11:21, 15 January 2021 (UTC)
 * , A single editor does not make a consensus. Nevertheless your edit is wrong for the following reasons. The article is about a science, and when talking of this science the name is rarely abbreviated. For example you will never see a sentence such as "Maths have many applications in other sciences". The abbreviation is common only when talking of teaching, which is not the subject of the article. Moreover, the common abbreviation is "maths" in some English speaking countries and "math" in other. As English Wikipedia is read in many countries, it must not presenting regional uses as common uses. So, although you are in good faith, further discussion on the talk page is needed to find a formulation that can be accepted by the community. D.Lazard (talk) 11:37, 15 January 2021 (UTC)

Splitting Lemma and Injective/Projective Modules
I don't know why you reverted my edit by saying "definitely wrong". In the article about splitting lemma, it helps the reader to know that (1) is equivalent to saying that A is an injective module and (2) is equivalent to saying that C is a projective module. One may say that it's not their definition per se, but it's definitely not "definitely wrong", thanks for reading. Sunilrampuria (talk) 10:07, 18 January 2021 (UTC)
 * , there is not any injective module or projective module in this article. Apparently you are confusing these concepts with those of injective functions and surjective functions, and you have not understood that in this article, arrows are not necessarily functions, and that the terms of monomorphism and epimorphism must be used instead. So, your above assertion is definitively wrong. D.Lazard (talk) 10:41, 18 January 2021 (UTC)

Definition of the limit of a function
Hi: You raised this topic on WT:WPM, noting the existence of both a punctured and unpunctured definition; and saying "whichever definition is kept, Wikipedia readers must be warned that both definitions are commonly used". I was thinking that it would make sense to add something to MOS:MATHS for the awareness of editors who read it in future. Since you originated the conversation, I just wanted to check (for politeness, rather than permission) that I wouldn't be stepping on your toes in any way if I did (which I'm planning to do fairly soon) &mdash; or if you had a different way forward in mind. Thanks, NeilOnWiki (talk) 14:05, 21 January 2021 (UTC)
 * , thanks for contacting me. You are not "stepping on my toes in any way". If I did not participate further on the discussion, it is essentially because I have not a clear opinion on the matter: there are clearly different regional traditions. Personally, I prefer the unpunctured definition probably because of my French education. Also, I think that the punctured version is less confusing, and thus better at elementary level (functions of one real variable), while the unpunctured version should be prefered at higher level (functions defined on a topological space). But this is only my opinion, and I have not enough arguments supporting it for arguing against any consensus. So, be free to go ahead. D.Lazard (talk) 14:55, 21 January 2021 (UTC)
 * Thanks. For what it's worth, my unrestrained opinion would be that the punctured version has no outstanding virtues mathematically and seems like editorial masochism, as it has several potential pitfalls intuitively; but that evidently wouldn't reflect the consensus expressed in English Wikipedia. Having had the discussion, my main aim is for it not to go to waste. I was a maths undergraduate at a British university decades ago and can only (though unreliably) remember the unpunctured version, so like you was quite surprised by its punctured alternative. NeilOnWiki (talk) 16:31, 21 January 2021 (UTC)

Algebraic equation edit
Hey I cant understand meaning of the sentence you added on the page algebraic equation can you please simplify or explain me meaning I would be great :-) Prankher31 (talk) 03:16, 23 January 2021 (UTC)
 * I did not add recently anything to Algebraic equation. I have just reverted an edit that makes the phrasing worse. Nevertheless, I have edited the sentence for clarifying it. D.Lazard (talk) 09:09, 23 January 2021 (UTC)

Can you please explain that sentence please!? Prankher31 (talk) 12:36, 23 January 2021 (UTC)

So is algebraic equation a super set in which polynomial equation is sub set? Prankher31 (talk) 15:35, 23 January 2021 (UTC)
 * No, for some authors "algebraic equation" and "polynomial equation" are synonymous, while, for others, "polynomial equation" is a more general concept than "algebraic equation". In other words, for these authors, an algebraic equation is a polynomial equation, but the converse is not always true. Nobody considers the set of all algebraic equations or the set of all polynomial equations. D.Lazard (talk) 15:53, 23 January 2021 (UTC)

I have edited the page algebraic equation one more time just see is it correct? Prankher31 (talk) 01:53, 24 January 2021 (UTC)

Page equation
Hey in sub topic algebraic equation of page equation there it was written that algebraic equation is either P=0 or P=Q which is not true because algebraic equation is of form P=0 and is also confirmed by user Jochen Bughardt Prankher31 (talk) 01:56, 24 January 2021 (UTC)

Difference between algebraic equation and polynomial equation
X^(1/3) + Y^(1/3) = 0 It is which type of equation algebraic or polynomial equation? Prankher31 (talk) 02:08, 24 January 2021 (UTC)

I was wrong don't worry to reply me :-) Prankher31 (talk) 02:33, 24 January 2021 (UTC)

Regarding deletion of line
Why is use of writing last sentence which you edited when it is clearly written above that polynomial equation refers to multi variate. Have you written for those people who consider polynomial and algebraic equation synonyms. SORRY TO DISTURB Prankher31 (talk) 09:48, 24 January 2021 (UTC)
 * This is not the place for discussing the content of a specific article. This must be done on the talk page of this article. This allows other editors to give their opinion in case of a disagreement between two editors. In any case, when you have concerns with some formulation in some article you must be much more specific, in order that everybody can understand the problem (here, I ignore to what "deletion of a line" refers, and to which article you refer, as I have recently reverted your edits of two different articles).
 * By the way, it seems that you are editing and discussing articles on subjects that you have just learnt in Wikipedia. This is not the way to proceed. If some formulation seems confusing, and you are not sure of the right way of fixing it, set the problem on the talk page for allowing more competent editors to fix it. If you do not understand some mathematical content, or you disagree with it, look on textbooks on the subject for learning it or checking whether Wikipedia formulation agrees with the common usage. In any case, Wikipedia is not a textbook, and is not a place for being taught. D.Lazard (talk) 10:24, 24 January 2021 (UTC)

First no body replies in talk page and second that line is creating confusion with other line at top of it Prankher31 (talk) 13:33, 24 January 2021 (UTC)

Please just last thing I want to ask
(Say just say Yes or No am I correct or not) Some people consider polynomial equation means it involves multivariate and algebraic equation means univariate. And some people consider polynomial and algebraic equation as same. I KNOW THIS IS NOT THE PLACE TO DISCUSS THESE THINGS BUT PLEASE Prankher31 (talk) 10:30, 25 January 2021 (UTC)
 * The answer is in the article, and detailed in section "Terminology". If you are not able to understand the English phrasing, I cannot be of any help to you. D.Lazard (talk) 10:55, 25 January 2021 (UTC)

(I just want to keep it short I have already irritated you) See in article you talked about most authors who consider polynomial equation as multivariate and algebraic equation as univariate but later you again said the following line "In the case of several variables (multivariate case), the term polynomial equation is usually preferred to algebraic equation." So confusion for me is this Prankher31 (talk) 13:42, 25 January 2021 (UTC)

Again let "you" in message be "author" Prankher31 (talk) 13:43, 25 January 2021 (UTC)

I understood thanks :-) Prankher31 (talk) 13:50, 25 January 2021 (UTC)

Change of basis
About the article change of basis: it's not true that a real symmetric matrix can be changed by an orthogonal change-of-basis matrix to have only 0, 1, and −1 on the diagonal. You can diagonalize it by such a matrix (and that fact is called the (real) spectral theorem), but that's all. Note that for an orthogonal matrix P, PTBP is the same thing as P-1BP. So the diagonal entries of the resulting diagonal matrix are exactly the eigenvalues of the original matrix (hence not just 0,1,-1). Could you correct the article on this point? BTotaro (talk) 00:37, 3 February 2021 (UTC)
 * I agree that my formulation was wrong, and I realized this just after my revert. But I was too tired for fixing it immediately. On the other hand, although the paragraph you added was correct it was too WP:TECHNICAL for a user who does not master already the theory of spectral theorems. I'll soon try to fix the section. D.Lazard (talk) 09:45, 3 February 2021 (UTC)

Please Don't Fail your Humanity
Try it with physical objects. Please it's visual fact.

I don't mean to say reality based mathematics does not work, it most certainly does.

However literary mathematical abstraction does not.

2+2=4 =8 (in Real reality based mathematics)

Please kindly kindly spare me some time and replace my edit. ❤️ BATTLEMAGE55 (talk) 17:49, 3 February 2021 (UTC)

February 2021
Apologies for reverting your redirect, sir or madam. Hockeycatcat (talk) 10:57, 12 February 2021 (UTC)

You have cancelled my modification from US English to British English.
https://en.wikipedia.org/w/index.php?title=Sign_relation&oldid=prev&diff=994367075

Hello. You have cancelled my modification from US English to British English. Could you provide the regulation of Wikipedia which support your action : choosing US English instead of the Original One, the British One? please.

Regards --Khwartz (talk) 19:25, 18 February 2021 (UTC)
 * , see MOS:RETAIN, WP:ENGVAR and MOS:VAR. You will see that my revert is supported by a decision of the WP:Arbitration committee. D.Lazard (talk) 20:34, 18 February 2021 (UTC)

maybe you'd know (what can we say about square matrix with strictly positive diagonal elements?)
yo DL,

i asked dr eppstein, who said it wasn't his specialty, and anita5192 has yet to respond.

since you edit a ton of math pages, maybe you'd know?

if i have such a matrix whose diagonal values are strictly positive, then can i say anything about the resulting eigenvalues also being strictly positive?

i don't think this is as-easy as i'd want it to be.

i am thinking the optimal decomposition (numerically precise) may yield eigenvectors whose eigenvalues are negative, and that imposing a strictly-positive constraint on the eigenvalues would yield a suboptimal solution? 198.53.159.44 (talk) 18:54, 22 February 2021 (UTC) sorry, i hate pinging but i figured i may as well ask you now that it's posted. anita was stumped. it's probably not as simple as it appears.
 * For the record, the matrix $$\begin{bmatrix}1&2\\2&1\end{bmatrix}$$ has a negative eigenvalue. D.Lazard (talk) 16:47, 9 March 2021 (UTC)

Reconsidering removal of analytic property of even and odd functions
Hello, M. D. Lazard, I want you to reconsider your removal of an analytic property of even and odd function. I would enjoy you reconsider this incredible formula, as you can see in the reference I give (it is a video), this result can be proven. I invite you to test this result in any graphing program and see with your own eyes that it holds true for the described functions. This formula may not hold true for strange and complicated mathematical objects, but it certainly holds true for normal analytic functions (polynomials, trigonometric functions, etc...). I hope I could reach you, and that you would understand this formula, and learn something new. :)

PS: By the way, this can property can also be seen on the List Of Integrals wiki: Lists of integrals — Preceding unsigned comment added by Jonathcraft (talk • contribs) 16:38, 19 March 2021 (UTC)
 * , I have moved the new thread to the bottom, as it is the rule for Wikipedia talk pages. Also, such a discussion on a specific article must normally be opened in the talk page of the article.
 * Sorry for my wrong edit summary. The formula is indeed correct. But there are hundreds of similar formulas. So criteria are needed for such an inclusion. Wikipedia rules for that are
 * The edit content must be supported by reliable sources; see WP:Reliable sources for a definition. YouTube and Wikipedia are not considered as reliable sources.
 * The edit content must be notable (see WP:Notability). Here, there are plenty of textbooks on the subject of the article and on integrals. So, notability requires that this formula appears explicitly in several commonly used textbooks.
 * So, your addition does not satisfy the main criteria for being included in WP. For the same reason, I have also removed the formula from  Lists of integrals. D.Lazard (talk) 17:38, 19 March 2021 (UTC)
 * So, your addition does not satisfy the main criteria for being included in WP. For the same reason, I have also removed the formula from  Lists of integrals. D.Lazard (talk) 17:38, 19 March 2021 (UTC)

Propose to add section to Euler's formula.
To whom it may concern,

This is Zhigen Zhao, Associate Professor of Department of Statistical Science at Temple University. Recently, me and my collaborators, both are tenured associate professor in Statistics from UNC Chapel Hill and Colorado State University has developed a new method based on the extension of Euler's formula to the probability theory via the binary random variable. This extension itself is of great importance. It bridges between the mathematics and computer science and has high impact on the modern research in data science, deep learning and artificial intelligence.

After we make the paper public available on arXiv, on March 19, 2021, the newspaper "Science Net", the primary media for the Chinese Academy of Science, the Chinese Academy of Engineering, China Association of Science and Technology, and the National Science Foundation of China, published a news report to highlight this extension of Euler's formula and its importance in applications.

I hope that this can justify the editing of the wiki page. We strongly believe that adding this information to wiki page could help the general public to expand the knowledge of this classic formula, understand its importance and connection to the modern research and application. If you need any additional information, please let us know. Your effort is greatly appreciated.

For your convenience, here are the links to the newsreport and the paper.

Link to the media coverage: http://news.sciencenet.cn/sbhtmlnews/2021/3/361383.shtm

Paper link: https://arxiv.org/abs/2103.00674

Here is our proposed section.

Applications in Statistics
In 2021, Euler's formula has been extended to random variables.

For any binary random variable A with possible outcomes of -1 or 1, then $$ e^{iAx} = \cos x+iA\sin x$$.

This result extends Euler's formula by equating two random variables, i.e., even with added randomness through an arbitrary binary variable, the Euler's formula remains to hold. Moreover, it reduces the exponentiation of a random variable to its one-degree polynomial. Combined with the development of the binary expansion testing framework in, Theorem 1 leads to the approximation to the characteristic function of any copula distribution and robust and powerful tests to distinguish non-uniform patterns in data from uniform randomness.

— Preceding unsigned comment added by SunAde81 (talk • contribs) 14:18, 20 March 2021 (UTC)
 * , two things before answering. Firstly, every post in a talk page must be signed with four tildes ( ~ ). Secondly, discussions on a specific article must be done on the talk page of this article, here Talk:Euler's formula, in order that other editors involved in the article can participate to the discussion.
 * Your request cannot be accepted because of the fundamental Wikipedia policy that excludes original research (WP:OR, more specifically WP:SECONDARY). In particular for being accepted, your request must include reliably published independent sources that allow evaluating the importance and the notability of your results (see WP:Notability). As your results are recent, we must wait on the publication of such secondary sources. Moreover even if such sources would exist, this does not imply necessarily that the result is important enough for being mentioned in Wikipedia.
 * Finally, if this result will be eventually included in Wikipedia, this would certainly not be in Euler's formula, as the readers of this articles are not supposed to know anything in statistic, and thus such a section would not be useful for them. D.Lazard (talk) 14:16, 20 March 2021 (UTC)
 * Finally, if this result will be eventually included in Wikipedia, this would certainly not be in Euler's formula, as the readers of this articles are not supposed to know anything in statistic, and thus such a section would not be useful for them. D.Lazard (talk) 14:16, 20 March 2021 (UTC)
 * Finally, if this result will be eventually included in Wikipedia, this would certainly not be in Euler's formula, as the readers of this articles are not supposed to know anything in statistic, and thus such a section would not be useful for them. D.Lazard (talk) 14:16, 20 March 2021 (UTC)

Thank you for advice, also consultation
I'm thinking of changing $R^{2n}$ to $$\R^{2N}$$ (Real coordinate space) or $$\R^{2N}$$ (cf.Real coordinate space) in order to unify it to blackboard bold. Your advice has helped(ing) me a lot.--SilverMatsu (talk) 04:19, 15 April 2021 (UTC)
 * I guess that you are talking of Several complex variables#The $Cn$ space. (Normally, formulas must be avoided in headings; one reason is that, for having a correct link to this section, I had to add an anchor in the aricle and to pipe the link here.)
 * IMO, the exponent must be 2n and the uppercase N as an exponent of $$C$$ is a typo. I'll do several bold changes in the paragraph, because this will be easier than explaining them here. Feel free to change them if you disagree with them. D.Lazard (talk) 08:38, 15 April 2021 (UTC)
 * Thank you for improving the article. I prefer the new section name. I got a natural link from the lead sentence. Also, there is a symbol about smoothness in the article, so your advice helped me and correctly. Blackboard bold is preferred. I used \mathcal for smoothness (Instead of \mathscr. This was sometimes seen in several complex variable textbooks) because it seemed like I was using boldface and blackboard bold confusingly. thanks!--SilverMatsu (talk) 14:03, 15 April 2021 (UTC)
 * I'm sorry, I forgot the link again. See, for example, Several complex variables. Also for \mathscr, see p.7 of Complex Analytic and Differential Geometry. I was taught this textbook in wikiproject:Mathematics. I don't think I've seen this notation in wikipedia's smoothness, but I think it's maybe okay. thanks!--SilverMatsu (talk) 14:45, 15 April 2021 (UTC)

Axioms of TS
"X belongs to τ" already means  "the empty set and X itself belong to τ", if I'm correct. What do you think about that ? If I'm correct, shouldn't simpler be better? Thanks. 光と物質のふしぎな理論 (talk) 20:53, 21 April 2021 (UTC)
 * , "X belongs to τ" means "$X ∈ τ$", and "the empty set and X itself belong to τ" means "$X ∈ τ and ∅ ∈ τ$", and this is not implied by "$X ∈ τ$". Apparently, you confuse "belongs to" (∈) and "is contained in" (⊂). D.Lazard (talk) 07:44, 22 April 2021 (UTC)

No, I'm not. I'm only saying if we assume "$X ∈ τ$" then we can conclude "$∅ ∈ τ$" from the TS's property. 光と物質のふしぎな理論 (talk) 08:08, 22 April 2021 (UTC)
 * Apparently, you are saying that if $$\tau=\{ X\},$$ then $\emptyset \in \tau$. This is definitively wrong. $$\{\emptyset, X\}$$ is a topology (the trivial topology), but $$\{ X\}$$ is not a topology.
 * It is true that, with the convention that the empty union is the empty set, the condition on unions of elements of $$\tau$$ implies $$\emptyset \in \tau.$$ But this cannot be used here, as readers of this article are not supposed to know the convention, and even if they know it, they are not supposed to understand immediately that the convention implies $$\emptyset \in \tau.$$ In summary, the previous version is correct and less technical (see WP:TECHNICAL). So, it is definitely better than your version. D.Lazard (talk) 08:41, 22 April 2021 (UTC)

You're now saying my version has no error. Above all, mine is more simple. Won't this benefit the reader? 光と物質のふしぎな理論 (talk) 11:36, 22 April 2021 (UTC)
 * Your version is certainly shorter, but is more difficult to understand and incomplete (for being complete it must be recalled that the empty union is the empty set). With this complement, your version would be not shorter and not simpler. Mathematical correctness is far to be sufficient for a correct writing. D.Lazard (talk) 11:57, 22 April 2021 (UTC)

The problem of current version is that it could make readers believe there is a set with "$X ∈ τ$" that satisfies all the axioms of TS except  "$∅ ∈ τ$". For this reason, it is clear my version is easier and correct. 光と物質のふしぎな理論 (talk) 00:33, 23 April 2021 (UTC)

Natural number
Thanks! I see: every section has its own disclaimer saying the very same! ―Nomen4Omen (talk) 15:06, 1 May 2021 (UTC)
 * , yes, but a disclaimer beginning by "In the next sections" is confusing if it does not apply to the section that follows immediately. D.Lazard (talk) 16:03, 1 May 2021 (UTC)

Vector notation: ISO example
Hi, D.Lazard. When you reverted a change to Vector notation today, what was your objection to using $a$ over $v$ in the ISO example? Adelphious (talk) 16:39, 6 May 2021 (UTC)
 * , the use of "v" for denoting a vector is must more common than "a". So there is no reason for changing it. Moreover, as you have not changed it everywhere, your version is confusing. Finally MOS:VAR says that any change like yours is forbidden if it is challenged and no strong reason is given for the change. D.Lazard (talk) 16:51, 6 May 2021 (UTC)
 * The strength of the reason motivated the change, and my entry here. What exactly about the reason did you object to? Adelphious (talk) 16:53, 6 May 2021 (UTC)
 * Your edit summary is a personal preference, not a reason ("a" has also the drawback to be an English word, and is use in an English sentence is often confusing. In any case, if you disagree, you must open a discussion on the talk page of the article, and we will see if there is a WP:consensus in favor of your edit. D.Lazard (talk) 17:05, 6 May 2021 (UTC)
 * I accept your invitation. Respectfully, I also dispute your characterization of my reason as personal preference. We'll continue there. Adelphious (talk) 17:17, 6 May 2021 (UTC)

Commentary
Leave your unwanted commentary on my talk-page, not on my personal page which contains notes for me. Kaptain-k-theory (talk) 16:07, 10 May 2021 (UTC)

"unexplained link removal"
It is links like that that got the article tagged as needing its wikilinks pruned. Please check out the Manual of Style, and ask a question sometimes if you don't understand something. Overall the quality of the writing is very poor and you are showing signs of trying to WP:OWN the thing. If you are currently revising the article I will refrain from editing it for a bit, but please give some thought to editorial conventions and overall readability. Elinruby (talk) 16:32, 12 May 2021 (UTC)

Completing the square
Hi DL,

I would like to make an edit to the Completing the square article, but I see on the talk page for the article that there was some edit warring back in January (because someone didn't source their edit, saying something along the lines of "it doesn't need a source; you can prove it easily yourself", which is of course silly). Anyway, since it looks like I might need the approval of another editor or two to make the edit, I thought I'd write to you first.

The edit I would like to make is to add a Generalizations section. In there I would like to put:


 * Completing the square for matrices (which I would move out of the Overview section): namely the formulas


 * $$x^{\mathrm{T}}Ax + x^{\mathrm{T}}b + c = (x - h)^{\mathrm{T}}A(x - h) + k \quad\text{where}\quad h = -\frac{1}{2}A^{-1}b \quad\text{and}\quad k = c - \frac{1}{4}b^{\mathrm{T}}A^{-1}b$$ for symmetric matrices, and the same with


 * $$h = -(A+A^{\mathrm{T}})^{-1}b \quad\text{and}\quad k = c - h^{\mathrm{T}}A h = c - b^{\mathrm{T}} (A+A^{\mathrm{T}})^{-1} A (A+A^{\mathrm{T}})^{-1}b$$ for general matrices.


 * The generalization that was added without a source in January, which I would phrase as follows, leaving the statement over a general field not of characteristic 2 until the end in order to make it more accessible:


 * Given a polynomial of degree $$2n$$ where $$n$$ is a positive integer, there exist polynomials $$h$$ of degree $$n$$ and $$f$$ of degree $$< n$$ such that $$p = h^2+f.$$


 * This generalises to polynomials over any field $$K$$ of characteristic not equal to 2: given a polynomial $$p$$ of degree $$2n$$ in the polynomial ring $$K[x]$$, there exist polynomials $$h \in K[x]$$ of degree $$n$$ and $$f \in K[x]$$ of degree $$< n$$ such that $$p=h^2+f$$. This can be proved by induction on $$n$$.


 * (I would source this of course)


 * The principal axis theorem, which (as stated in the introduction of that article) is a generalization of completing the square. I would probably explain more exactly why it is a generalization of completing the square.

Do you think this would be a good edit? Thanks, Joel Brennan (talk) 12:01, 13 May 2021 (UTC)
 * IMO, for expanding this article, one must focus to applications and generalizations that are widely used. For this reason, I think that the second item is dubious, because I do not know any classical application of it.
 * I agree to move the matrix case outside the "Overview" section. It must be made correct by stating that the matrix must be invertible. However, it seems much less important than other applications/generalizations that are presently lacking.
 * IMO, the assertion "the principal axis theorem is a generalization of completing the square" is original research, but there are related results that are direct applications of completing the square, and are currently lacking.
 * Among the important applications, there are the following ones:
 * Every quadratic form (homogeneous polynomial of degree two) over a ring in which 2 is a unit can be written as a linear combination of squares by completing the square iteratively (and using the identity $$xy=\frac 14 ((x+y)^2-(x-y)^2)).$$ Sylvester's law of inertia asserts that, over the reals, the numbers of coefficients that are zero, positive or negative do not depend on the way for obtaining them. In matrix terms, this is expressed by saying that a square matrix is congruent with a diagonal matrix, and that the sequence of the signs of the diagonal entries depends (up to its order) only of the input matrix. The principal axis theorem is the fact that the linear forms that are squared can be chosen as pairwise orthogonal (the proof does not use completion of squares).
 * Every multivariate polynomial of degree two may be written as a linear combination of squares of linear polynomials plus a term that is either zero, a constant, or a linear homogeneous polynomial. The numbers and the signs of the coefficients, and the nature of the non-quadratic term are the basis of the classification of the conic sections, quadric surfaces, and more generally, quadric hypersurfaces.
 * A generalization of the completion of the square is the polynomial transformation that transform a polynomial of degree $n$ into a depressed polynomial (that is a polynomial without a term of degree $n − 1$) This is a standard way for simplifying cubic and quartic equationss before solving them; see Depressed cubic and Depressed quartic.
 * IMO, these three items deserve to be mentioned in the article, and are more encyclopedic than what you suggest. D.Lazard (talk) 16:08, 13 May 2021 (UTC)


 * Thanks for your input; I will implement these into the edit also (of course I won't make the Generalizations section huge, but it is important to not exclude any useful generalizations). Depressing a polynomial is a great example of a generalization of completing the square, which I failed to think of when I wrote my original list above. As for the second item in my list above, one of the reasons I think it should be included is because its simplicity makes it mathematical beautiful (or at least "algebraically beautiful", if you think the former is an overstatement); when a mathematician sees it for the first time, I imagine they think "Of course! Why didn't I think of that!", as I did this morning when I saw it. Moreover, it would complement depressing a polynomial quite nicely, as they are both operations that simplify a polynomial (Depressing a polynomial makes one of the terms vanish, while the other result expresses a polynomial of degree 2n only with terms of degree ≤ n (and an application of the squaring function)).


 * Having only seen the result this morning, I of course also do not know of any applications, but I am sure they must exist; nice algebra tricks such as this one find uses all over the place – for example, something I just thought up is that the trick can be used to solve a very restrictive class of quartic equations; when we use the trick to write $$ax^4 + bx^3 + cx^2 + dx + e$$ as $$(ux^2 + vx + w)^2 + rx + s$$, if $$r$$ happens to be zero, then we can solve the quartic equation by $$ux^2 + vx + w = \pm\sqrt{-s}$$ (and then solve the two resulting quadratics by any method we like; perhaps by completing square, in the taste of our discussion :p). Of course I wouldn't include this in the edit; it is just something I quickly thought up to demonstrate that the result is useful. Joel Brennan (talk) 19:03, 13 May 2021 (UTC)

Abel–Ruffini theorem
Thank you for cleaning up the Proof section. However, you used the pronoun "this" in two places. I don't think it is clear which theorem you are referring to with each "this." Could you please replace each of the pronouns with the name of the theorem to which it refers? Thanks! — Anita5192 (talk) 15:19, 25 May 2021 (UTC)
 * I have fixed two possibly ambiguous uses of "this". But I do not know whether they are those that you are talking of. In any case, I do not own the article and you can fix the issues yourself. If you are wrong, this is not a problem, as I watch the article, and it is easier to fix a misinterpretation than to find what may possibly be misinterpreted. D.Lazard (talk) 15:53, 25 May 2021 (UTC)


 * Thank you! I changed the two instances I was referring to. You can correct them if they are wrong.—Anita5192 (talk) 17:31, 25 May 2021 (UTC)

Backslash
Hi, if you have time, would you have a look at Backslash, please? I'm reluctant to delete something that may be valid just because it has a long outstanding cn request. Is it at least credible? --John Maynard Friedman (talk) 18:23, 26 May 2021 (UTC)

Revert of an edit in the 'Talk' part of Cross-product
Bonjour

J’ai jeté un coup d’œil à votre page perso et je dois dire que je suis assez impressionné. D’après cette page, vous êtes mathématicien (ce qui est aussi mon cas, bien que mon niveau soit probablement très inférieur au votre). C’est dire si votre avis m’intéresse.

En supprimant mon message, non seulement vous me refusez votre avis mais vous m’interdisez d’avoir l’avis de qui que ce soit ! Vous trouverez peut-être le mot un peu fort mais cela s’apparente à de la censure.

S’il est légitime de supprimer une modification dans le corps même d’un article, je ne savais pas que (mis à part les trolls, les insultes personnelles, etc.) on pouvait le faire dans la partie discussion. Dans cette partie je pensais que l’on pouvait s’exprimer librement (à propos du sujet bien sûr), argumenter, avoir tord ou raison, bref discuter.

Dans un esprit de dialogue « wikipédien », je vous demande donc de bien vouloir rétablir mon message car je ne tiens pas du tout à me livrer à une guerre d’édition. Vous aurez tout loisir d’exprimer votre point de vue, de manière concise ou plus détaillée pour m’expliquer pourquoi et combien c’est nul. Mais cela permettra aussi à d’autres personnes de s’exprimer.

Maintenant que j’ai réagi sur la forme, je voudrais réagir sur le fond


 * vous parlez de « considérations philosophiques ». Il ne vous quand même pas échappé que ces « Trois lois » font directement référence à celles d’Asimov ! C’était juste une manière d’engager le dialogue sur le sujet très controversé de « pseudo-vecteur » dont le produit vectoriel en est l’archétype.
 * vous dites que « cela ne cherche pas à améliorer l’article ». Mais dans l’article, on peut lire que « lorsque l’on inverse le système de coordonnées la définition du  produit vectoriel doit être changé en son opposé ».

Using the cross product requires the handedness of the coordinate system to be taken into account (as explicit in the definition above). If a left-handed coordinate system is used, the direction of the vector n is given by the left-hand rule and points in the opposite direction. This, however, creates a problem, because transforming from one arbitrary reference system to another (e.g., a mirror image transformation from a right-handed to a left-handed coordinate system) should not change the direction of n. The problem is clarified by realizing that the cross product of two vectors is not a (true) vector, but rather a psudovector.

Alors, quand je dis que, en mathématiques, le produit vectoriel de deux vecteurs est un vecteur et qu’il doit en être de même en physique (même si on le qualifie d’axial ou de pseudo), c’est hors sujet ? Cela ne mérite pas que l’on en parle ? Inutile de dire qu’il n’est pas nécessaire d’adapter la définition du produit vectoriel à chaque changement de base ?

Cordialement--KharanteDeux (talk) 14:41, 30 May 2021 (UTC)
 * The guidelines for talk pages begins with Your post consists only of personal considerations, without any reference to any reliable source. Moreover, your post can be summarized by saying that mathematicians an physicists view differently vectors and pseudovectors. This is a fact that Wikipedia cannot change. It is not the role of Wikipedia to decide how people must view any concept. So your considerations are of no help for improving Wikipedia.
 * I will not restore you post. However, if you write a new post that is signed and that focus on the improvements that you propose (nothing is suggested in your first post), I'll not revert you again. D.Lazard (talk) 17:37, 30 May 2021 (UTC)


 * Effectivement, l’usage de la page ‘Discussion’ est plus restrictive que je ne le pensais. Je ne sais pas encore comment je vais faire mais il est exclu que je réédite mon message tel quel. Juste un point que je voudrais préciser. Vous dites

mathematicians an physicists view differently vectors and pseudovectors. This is a fact that Wikipedia cannot change. It is not the role of Wikipedia to decide how people must view any concept.


 * Que les mathématiciens et les physiciens aient des points de vues différents, c’est bien naturel et si j’ai laissé croire le contraire c’est que je me suis mal exprimé. Ce que j’ai tenté de dire c’est que si on veut utiliser l’outil mathématique, il faut le respecter. En ce qui nous concerne, le produit vectoriel utilisé en physique est soit mathématique soit non mathématique (y aurait-il une troisième voie ?) Je vois mal en quoi le produit vectoriel mathématique serait insuffisant pour traiter les problèmes de la physique classique mais si c’est le cas Wikipédia devrait le préciser et donner une source justifiant cette décision.--KharanteDeux (talk) 16:47, 31 May 2021 (UTC)

Mathematical proofs and copyright
I've been editing Wikipedia for 7 years (and this section appears to have existed intact for over a year, by the way) and this is the most ridiculous thing I've ever seen. A reproduction of a mathematical proof is forbidden?! What? Then any mathematical proof or definition, once it's found, can never be presented again, because it occurs in the original article, and so reproducing it again would be violating the copyright? Is this the logic?! — Preceding unsigned comment added by Strecosaurus (talk • contribs) 11:48, 9 June 2021 (UTC)
 * Mathematical theories, including mathematical proofs, are not copyrightable. In order not to be considered original research, it is mandatory to cite the source, but you certainly know this, unlike D.Lazard who prefers his own considerations to what the sources say. --Turbojet (talk) 16:16, 23 June 2021 (UTC) (VRTS advisor)
 * Non-lawyer here, but I'm pretty sure of this: The idea of a given proof is not copyrightable, but the exposition is.  It's similar to how algorithms are not copyrightable (though they may sometimes be patentable), but programs implementing the algorithms can be copyrighted. --Trovatore (talk) 15:43, 25 June 2021 (UTC)
 * Programs, yes, are protected, but mathematical formulas and algorithms are not. The explanatory texts in the demonstrations are protected if they cross the threshold of originality, but not simple connecting words, as "being given", "where", "therefore", "if and only if", "it follows", etc. So, a proof can be published on Wikipedia if the detailed explanations are omitted or reformulated. See also Category:Articles containing proofs. --Turbojet (talk) 05:59, 27 June 2021 (UTC)

I not sure why we are talking in this place. I don't think D. Lazard was involved in the first post. See Wikipedia talk:WikiProject Mathematics/Archive/2021/Jun.--SilverMatsu (talk) 01:22, 30 June 2021 (UTC)

thank you !
Thank you for the fix and explanation. I think I should have written that in edit summary. However, the post doesn't seem to be reflected in the current diff, so I'll post here, because I think the article talk page should discuss the newest diffs. But I just would like to thank you for your diffs and explanations.--SilverMatsu (talk) 01:22, 30 June 2021 (UTC)

Laws of indices
I have reverted this edit. It makes no sense to name a horse Laws of Indices UNLESS that is supposed to allude to the topic of laws of indices that is treated in secondary-school mathematics courses and used daily by everyone. I have redirected it, not to Exponentiation, but to Exponentiation, which deals explicitly with laws of indices. I was taught to call them "laws of exponents", but in this context this is a synonymous word that is conventional in some places. I put a disambiguating hatnote at the top of the Exponentiation article. Michael Hardy (talk) 20:05, 31 July 2021 (UTC)

Exponentiation
I am reassessing exponentiation against the good article criteria. Since you have heavily edited the page this calendar year, I am inviting you to leave comments there, if you desire. Even if we can't save it, hopefully we can make it better in the nearly decade and a half since it was promoted. Thanks, Urve (talk) 09:37, 5 August 2021 (UTC)

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Goldbug Numbers
Curious why the Pillai conjecture info for Goldbach page was removed. The OEIS page is very well documented. Does wikipedia need additional info? Goldbugs are not the important topic here, the link between Pillai and Goldbach is, how could this fact possibly be sourced without mentioning Goldbugs? Also, Goldbug numbers have been discovered at least 3 independent times, not sure if that matters.

If you are saying that the claim that Pillai and Golbach are linked needs a direct source, its mentioned in the OEIS, but maybe it needs to be more clear in OEIS?

If you are saying that the claim needs to be from another academic paper, are you up for writing one with me? ;^) — Preceding unsigned comment added by AgileScribe (talk • contribs) 14:42, 16 September 2021 (UTC)


 * Please, sign your posts in talk pages with four tildes ( ~ ).
 * It is a basic policy of Wikipedia that every content must be reliably sourced, and that original research is forbidden. A mathematical content is considered as original research if it has not be published in a peer-referred journal, or it has not been discussed in reliable WP:secondary sources. OEIS may be a source for results of computations, but is not a reliable source for a mathematical content. Here, the first paragaph is sourced by OEIS, but the OEIS page contains references to the original Pillai's article, and to a regularly published secondary source. So, I have not removed the paragraph. On the other hand, the OEIS page to which was linked the second paragraph does not contain any other source than unpublished texts by Craig J. Beisel, the author of OEIS page. So no reliable sources and no secondary sources are available, and the paragraph is thus definitively not suitable for Wikipedia. D.Lazard (talk) 12:59, 16 September 2021 (UTC)


 * Thank you. Yes, this makes good sense. I thought OEIS qualified as peer-referred since it has editors. Sloane and team certainly don't just let anything through! It's unfortunate that this result will have to remain relatively unknown, I think it might be a thread leading to something interesting. I have attempted to add more clarity on this point to the OEIS site and I suppose in time if it is important it will eventually make its way to wikipedia. Unfortunately, I am not in academics so writing a paper on the result myself is not likely going to happen. Just trying to publicize the result in any way I can in case it gives someone like you with more experience some insight into the problem. If you have suggestions on where this original research should be published and how, I would be most interested in your advice. AgileScribe (talk) 13:10, 16 September 2021 (UTC)


 * It would also seem that the last bullet point in that section on twin primes suffers from the single OEIS author problem as well? The only source is a unpublished note by Dubner himself. If this is not the case, could you explain how the two entries are sourced differently? AgileScribe (talk) 13:14, 16 September 2021 (UTC)
 * This last bullet refers to OEIS only for computation results, which is fine. The same bullet refers also to a Dubner's paper. I do not know whether this paper has been published. In any case, it explains well the origin of these conjectures, and how they are natural generalizations og Goldberg conjecture. So removing this item would need a specific discussion. D.Lazard (talk) 13:54, 16 September 2021 (UTC)

Dear Dr. Lazard,

Thank you so much for getting back to me regarding editing policies of Wikipedia and our work on the quintic. I understand now what needs to be done, which is very helpful as we are primarily Finance practitioners. The motivation of our work was to provide an accurate closed form formula in radicals to the quintic, that works globally. Unlike traditional numerical methods such as Newton, which are primarily local, our method is specific to the quintic and uses distinct mathematical properties that always lead to an accurate approximation from the first iteration (|formula- root | < 4.32× 10−3 and |formula/root -1| < 2.51×10−2). In other words, everybody knows that the quintic cannot be solved in radicals. However, the intriguing finding here is the existence of a common-sense accurate closed formula.

Our only goal is to share this finding for the pure love of mathematics. Would you please be kind to suggest math journals that you deem a good potential fit? We will of course take into account your valuable feedback.

Thank you so much for all your help and I very much appreciate all your contributions to Wikipedia! Kind Regards,Abdelmissa (talk) 22:47, 7 October 2021 (UTC)

Kronecker
Hi! Would you give your opinion to the last subject in "Factorization of polynomials" talk page that I posted? Tsukitakemochi (talk) 16:59, 1 November 2021 (UTC)

Stop edit warring
Please don't edit war. Please reach a consensus before reverting. You may be banned 🚫 from editing forever. Nishānt Omm (talk) 12:54, 7 November 2021 (UTC)
 * WP:NOTTHERE D.Lazard (talk) 13:40, 7 November 2021 (UTC)

November 2021
Welcome to Wikipedia. Editors are expected to treat each other with respect and civility. On this encyclopedia project, editors assume good faith while interacting with other editors. Here is Wikipedia's welcome page, and it is hoped that you will assume the good faith of other editors and continue to help us improve Wikipedia! Thank you very much! HistoryofIran (talk) 21:00, 7 November 2021 (UTC)

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Riemann surfaces
Would you care discussing your recent revert at Talk:Riemann_surface? Sylvain Ribault (talk) 22:54, 17 November 2021 (UTC)

Lead for Order (group theory)
Hi Lazard! I saw that you reverted my edit of the lead for Order (group theory). Let me explain the rationale of my edit and hopefully we can come to a consensus. As I see it, the current lead has some minor problems I tried to address in my edit; here they are:


 * The paragraph on Lagrange's theorem is only true/well-defined when G is a finite group
 * The phrase "if the group is seen multiplicatively" is confusing for people not already familiar with groups and does not link anywhere; likewise, the "product of **m** copies of **a**" ought to mention that it is under the group's operation (again for people not already familiar with groups)
 * o(x) is also sometimes used to denote order (e.g. in Roman's 'Fundamentals of Group Theory')
 * The lead should more explicitly (and more immediately) address that "order" in Group Theory refers to two related but distinct concepts
 * Why not put notation in the first paragraph? (as in Absolute Value, Logarithm, Exponentiation, etc.)

Which of these issues in your view merit an edit? Winthrop23 (talk) 16:28, 18 November 2021 (UTC)
 * This should had been placed in the article talk page. I you want a further discussion, place it there.
 * Last item: MOS:MATH
 * Last but one item: Removing brackets does not make a distinct concept. However, I have modified the order of the sentences for making this clearer, and also for a less pedantic phrasing (unneeded use of "cardinality" and "multiplicatively", for example).
 * Two first items: I have edited the lead for fixing these points.
 * Notation: I agree that $$\mathrm o(x)$$ and $$\mathcal o(x)$$ seem more common than $$\operatorname{ord}(x).$$ A discussion is needed in the article talk page for deciding whether one adds these notations and whether one removes $$\operatorname{ord}(x).$$
 * D.Lazard (talk) 17:27, 18 November 2021 (UTC)

Thanks
For your correction to this. Yes, I was rather lazy with the boundary condition.

And, yes, I just could not resist being a bit mischievious with that.

Regards Aoziwe (talk) 12:57, 27 November 2021 (UTC)


 * PS I am not sure if the "2 and 3"ing is OR. Lower middle school math would be more than sufficient to follow?  Cheers.  Aoziwe (talk) 13:04, 27 November 2021 (UTC)

Can you explain that?
Why have you reverted my edit in Algebraic indentities? Nishānt Omm (talk) 03:53, 28 November 2021 (UTC)
 * This is eplained in the edit summary: MOS:VAR is the reason of my revert. More precisely, you did two edits.
 * The first one consists of changing spaces in the source of LaTeX formulas. The does not change the rendering but it is a WP:disruptive edit, as it requires time of other editors for verifying that no error has been introduced.
 * The second edit consists of changing the name of the basis of exponentiation from $b$ to $x$. Again, both choices are correct and MOS:VAR applies. The reason that you give for the change is wrong: $x$ is standard, but not mandatory, for variables of functions. For other variable uses, other letters are common. In particular, for bases of logarithms and exponentiation, $b$ is very commonly used, and has the advantage of helping to remember that negative values are excluded. D.Lazard (talk) 09:53, 28 November 2021 (UTC)

Meaning reverted
According to what does it have to be the common definition? Uni3993 (talk) 10:29, 6 December 2021 (UTC)
 * This revert has be done according the guideline MOS:OL, which says . Moreover WP:COMMONSENSE applies also: readers who do not understand the first sentence of Definition, will certainly not be helped by a link to a technical article on semantics. D.Lazard (talk) 10:52, 6 December 2021 (UTC)

Tip for verifying content
Hi. If I am not mistaken, you seemed to indicate here that it takes a lot of work to verify some of my edits. If so then here's a tip for quickly verifying the correctness of edits in which no information was added, removed, or changed. I'll use the article Total order as an example.
 * 1) Have the article open and then in a new tab, go the article's revision history and view the version of the article before any edits were made (e.g. this edit from 19:20, 21 November 2021).
 * 2) In both pages, scroll down/up as necessary so that the first sentence of the article (i.e. "In mathematics, a total or linear order is a partial order in") is at the very top of your screen/view area. The goal is to make it so that the location (on your screen) of the sentence "In mathematics, a total or linear order is a partial order in" does not change when you switch tabs.
 * 3) It should now be easy to quickly verify that the information content of the pages are identical because the location of vast majority of the text on your screen will not change much when you switch between tabs. Scroll down by the same amount on each page and then repeat the verification.

By doing this, it typically takes me less than a minute to verify my changes. You can also have the old version of the page open in another window instead of another tab. Best wishes. Mgkrupa 22:11, 12 December 2021 (UTC)
 * If you do, says, 100 changes in a single edit, it may occur that 50 do not change the rendering, 30 fall under MOS:VAR, 10 are improvements, 10 are disimprovements, and the last 10 require to be edited since both the old version and new one are confusing. This makes the verification and the correction of your edits very time consuming. So, please, do not change several sections in a single edit, and do not do make changes of very different nature in the same edit. Said otherwise, make edits that can be described with an edit summary of less of 80 characters. Thanks. D.Lazard (talk) 22:59, 12 December 2021 (UTC)

Summation in Newton's identities article
Hi D.Lazard, I would still like to change the summation symbol for $$e_2$$ on the Newton's identities article. I think it would be a bit easier to read if it were like the one on the French Wikipedia: https://fr.wikipedia.org/wiki/Identit%C3%A9s_de_Newton

If you agree, I'll make the change.

Best regards, Kier07 (talk) 15:02, 23 December 2021 (UTC)
 * , I would agree with the change, if you add also the line with dots.
 * However, this is the wrong way to proceed, since the place of such a discussion is the talk page of the article. See WP:BRD for details on procedures for discussing a revert. D.Lazard (talk) 10:12, 24 December 2021 (UTC)
 * OK, done (and apologies: I will read up on the relevant procedures). Kier07 (talk) 22:38, 24 December 2021 (UTC)

Talk:E (mathematical constant)
Thank you for policing this article. I have added a Template:uw-vandalism2 to User talk:165.234.101.234. Then that user added another bad edit. I think it deserves a Template:uw-vandalism3. Best wishes OrewaTel (talk) 21:49, 12 January 2022 (UTC)

January 2022
You are edit-warring at the moment. Instead of discussing matters in a careful way, you reverted without due reflection, posting an edit summary WP:CIR: correct mathematical meaning is required. Your edits unfortunately indicate WP:CIR: see below. I am asking User:Johnuniq to help you understand the mistakes you have made and to explain why these types of edit do not improve wikipedia.

Recently, on Wikipedia talk:WikiProject Mathematics, you made comments on culture/differential & integral calculus. In the same edit you wrote, "The strong relation between these two subjects makes artificial to distinguish them." That phrase makes no grammatical sense.

In the same way, the edit where you "corrected" field of complex numbers to your preferred field of the complex numbers cannot be justified. As I've written, the French phrase "corps des nombres complexes" is translated into English as "field of complex numbers". To see that, the correct thing is to use WP:RS and WP:V. Bourbaki's General Topology, Chapter IV is devoted to real numbers, with section 4 entitled "The field of real numbers". For the original French version, Topologie Générale, section IV.4 is entitled, "Le corps des nombres réels". The same applies to Dieudonné's Foundations of Modern Analysis/Fondements de l'Analyse Moderne (because they're the same author). Mathsci (talk) 01:50, 4 January 2022 (UTC)
 * This talk page is not for discussing edits on a specific article. The place of such a discussion is the talk page of the edited article. So, I'll not discuss here your edit that I reverted and the edit war that you started by reverting my revert.
 * About WP:CIR: I have put the link in my edit summary only because you have used it previously in your edit summary. Otherwise, I would never use such a threat of incompetence, at least per WP:AGF. By the way, it is interesting that you threat as incompetent a wikipedian that did more tham 25,000 edits whose less than 1% have been directly reverted. D.Lazard (talk) 10:05, 4 January 2022 (UTC)
 * Please see Wikipedia talk:WikiProject Mathematics. There has been edit-warring by you, hence the information template. Thanks, Mathsci (talk) 11:08, 4 January 2022 (UTC)

15 Jan 2022, Lem -- I hope this reaches D. Lazard. [You will leave it or delete it as you desire -- if you see it.] I'm about to give up (again) on Widi-pedia. The quibbles were enough for me, but gratuitous edits mean you have to sit guard over all you write forever. This is no place for mathematicians to have a quiet discussion. Years ago, I was on Rev. Magnus Wenninger's SIG related to his interest in domes, symmetry, etc. I was tolerated by some famous mathematicians. I even questioned John Conway's introduction of the term pro-canonical; as it violated one of his own principles. In that case he was trying to generalize a term he had already introduced. "canonical"; which was like calling a rectangle a 'pro-square'. &       In any case, the Pythagorean Triplets conflict is no big deal, but I would like to write about it somewhere. My Talk section for the 'Axonometric Projections' topic still has my citation of a DOI for the '89 article with the recent correction (by me). That's the only source they will get. Is it true that one's talk section is supposed to be free from unwanted edits? Then why write in the actual 'Article' section? &        I also want to do some more work on Axonometric Projections in four dimensions. (I had a note from Prof. Ziegler last winter, but don't want to disturb him again; at least not with chatter.)  This, sum of N squares generalizes into higher dimensions. The Pythag. Trips. in my view is just the 2-D version. The 1- version is trivial. Thanks for you time. Lemchastain (talk) 19:03, 15 January 2022 (UTC)

Thx
Thanks for this correction. Who had brought that up??? - DVdm (talk) 17:59, 23 January 2022 (UTC)

Quartic Formula
If you can't read the image...... then YOU can't read the image. I can read it just fine.

There's literally no downside in leaving it there for the people who can read it as opposed to accomodating for every ridiculous case where a person can't read the image.

As for your last part, it's not original research. The formula has been known for hundreds of years. — Preceding unsigned comment added by SineofTan (talk • contribs) 23:48, 5 February 2022 (UTC)

Chinese remainder theorem
Hello D.Lazard!

Please tell me, does the term "positive" in your understanding mean n=1,2,3,... or n=0,1,2,3,... ?

In my understanding, "positive" is n=1,2,3, ... (that is, not including "0"), and "not negative" is n=0,1,2,3,... (that is, including "0").

With best wishes Alpha-Gamma (talk) 09:57, 16 February 2022 (UTC)
 * My edit summary was an error. We agree with the definitions. However, both versions of the article are formally correct, as zero is clearly not a solution to the problem. So, as this is in the lead, where things must be as less technical as possible, it is better to use "positive" which is less jargon than non-negative. Howover, as Sun-tzu did not used negative integers, I'll use natural number instead of integer. D.Lazard (talk) 10:50, 16 February 2022 (UTC)

In re Jacobian matrix and determinant
This is regarding the reversion of my edit in the Jacobian matrix and determinant article - could you please elaborate on where I went wrong? I do realise that per Real number, $R$ also may be used to indicate the set of real numbers, but have observed that $$\mathbb{R}$$ is more widely used, hence leading to the change. Furthermore, while there is no need to change the mapping arrow from the previous one to "$$\mapsto$$", I do think that the latter is more appropriate and unambiguous. I also am unable to understand why the return symbol exists between 'i.e.,' and the mathematical formula, when it works perfectly finely if that symbol is replaced by a space. Viv73 (talk) 10:10, 17 February 2022 (UTC)
 * MOS:FORMULA says Your edit is a tentative for such a large-scale formatting change. However there is another reason of my revert: A formula must either be formatted in html with a template math or in LaTeX with a markup $$...$$ . But mixing the two styles in the same formula is forbidden, as well as using several templates math or a markups $$...$$ in a single formula. This is what you did for most formulas that you have edited. D.Lazard (talk) 10:31, 17 February 2022 (UTC)
 * Also, your use of \mapsto is definitely wrong. See Function (mathematics). D.Lazard (talk) 10:45, 17 February 2022 (UTC)
 * Oh! Ta! Viv73 (talk) 15:14, 17 February 2022 (UTC)

Long-term pattern of unwarranted, inappropriate, and aggressive resistance to change in the article cubic equation
I have submitted the following to the Arbitration Committee, regarding a need to deal with your bad behavior: Excessively reverting other editors changes to the cubic equation article.

"User D.Lazard has exhibited a persistent pattern of aggressively suppressing even minor changes that do improve the accuracy or readability of the Cubic equation article.

I'm not sure what measures to take to remediate the situation, but it appears that D.Lazard is not able to appropriately tolerate other editors' changes to this imperfect article, and is treating it like private property. This message is my request to you for instruction and help about what to do about a contrarian editor.

The article is fairly important for the history of mathematics: The solution to the cubic equation was the first solution to a polynomial equation since the solution to the quadratic equation, which was known in late classical times through geometric construction. This began a sequence of efforts to solve higher-order (quartic equations, quintic equations) general polynomials which ultimately were proven impossible (the quartic equation -- fourth order -- was the last solution possible using basic algebra). Mathematical understanding greatly expanded around these efforts, beginning with the cubic, which showed a clear, practical use for imaginary numbers and complex numbers. Although the rest of the mathematical progress is difficult to follow, the motivation for complex numbers is generally understandable for anyone with a good high-school education in algebra. Hence many mathematicians have a dedicated interest in ensuring this article on the cubic is well done.

The intrusive interruption of even incremental refinements to the article by user D.Lazard is a community-contrary obstacle to improvement."

No article on the Wikipedia is your property, and you are not a guardian or gatekeeper of other editors' changes. Your behavior is not acceptable, and must change for the better. Astro-Tom-ical (talk) 03:12, 18 February 2022 (UTC)

Link to Lemma in Gauss's lemma
Hi, can you explain why there is no need to link the word lemma in Gauss's lemma (polynomials)? I think a lay reader may find helpful to be redirected to the meaning. --Vilnius (talk) 13:17, 18 February 2022 (UTC)
 * The main reason of my revert is MOS:BOLDLINK:. Moreover, it may be confusing to split the bolded phrase into isolated words. Linking to Lemma is not really useful, since the fact that a lemma is a statement is explained in the first sentence. In any case, the fact that could be interesting for a reader, it the reason for which this particular theorem is called a lemma. As far as I know, this is not explained in the link you provided, nor in any Wikipedia article. So, this is not a good idea to link to an article that does not answers to the main interesting question: it is wasting reader's time. D.Lazard (talk) 15:39, 18 February 2022 (UTC)

Comparison of number bases
I have included a link to the main article, radix. This is why I removed the template! Username142857 (talk) 11:56, 19 February 2022 (UTC)
 * Including a link does not solve the problem of WP:REDUNDANTFORK nor that the draft is intended as an WP:Original synthesis. I'll revert your revert. In any case, removing editors comment is not the right way to have, in the future, your draft accepted as an article. D.Lazard (talk) 12:28, 19 February 2022 (UTC)
 * Then what are 'Main article' links for anyways? Username142857 (talk) 12:52, 19 February 2022 (UTC)
 * The template says: 'This article duplicates the scope of other articles, specifically Radix. Please discuss this issue on the talk page and edit it to conform with Wikipedia's Manual of Style.' Well, you could argue that Radix duplicates the scope of Mathematics. So I really don't know what you're going on about. Username142857 (talk) 13:44, 19 February 2022 (UTC):
 * Apparently, you are unable to understand WP:DUPLICATEFORK. undefined is for a section that summarizes another article, not for an article that duplicates another article. D.Lazard (talk) 14:24, 19 February 2022 (UTC)
 * That page doesn't exist! Username142857 (talk) 14:42, 19 February 2022 (UTC)
 * Sorry, WP:REDUNDANTFORK. D.Lazard (talk) 16:34, 19 February 2022 (UTC)
 * Can this article be merged with Radix? Also, again, according to that logic, Radix itself should be deleted because it duplicates the scope of Mathematics. Username142857 (talk) 01:27, 20 February 2022 (UTC)

linear map
ok, but it was not vandalism from my point of view, not my intention. Ffffrr (talk) 14:25, 27 February 2022 (UTC)
 * I never considered your edit as vandalism. It is because I assumed your good faith that I have provided links and explanations in my edit summary. Otherwise, I would not have spent time for that. D.Lazard (talk) 14:36, 27 February 2022 (UTC)
 * On the page of the rollback edit one of the tags was marked vandalism, I guess that's something automatic from the program then. Ffffrr (talk) 14:39, 27 February 2022 (UTC)

Ok
Hello. I specified the source you requested. But I am a new user on wikipedia. I would be glad if you help. AntaresH2O (talk) 11:03, 10 March 2022 (UTC)
 * For being acceptable in Wikipedia, a result must not be original research (see WP:OR for a description of what is considered here as original research). In mathematics, this means that a result must be published in a peer-reviewed journal. Moreover, this condition is not sufficient: the result must also have been dicussed in some reliable secondary sources (see WP:Secondary sources). This is required for establishing the notability of the result (see WP:Notability), since non-notable results do not deserve to be mentioned in an encyclopedia.
 * So, the content that you want to add to Omega constant cannot be accepted because the foundational Wikipedia policies. I'll revert it again. D.Lazard (talk) 12:23, 10 March 2022 (UTC)

You say that I should publish my work in the journal. Well, I am quite an amateur when it comes to broadcasting. I'll be back again after a certain time. Thanks for pointing out my mistakes. AntaresH2O (talk) 12:37, 10 March 2022 (UTC)


 * You did not any mistake, except that Wikipedia is not the place to publish your personal work (or anybody's original work). You may learn more on Wikipedia purpose, and what is accepted or not, by reading WP:What Wikipedia is not. D.Lazard (talk) 13:11, 10 March 2022 (UTC)

Group theory
Your removal of the new section was premature. The mathematical point that I was making concerns the existence of infinite groups in the 3-dimensions of the physical world. These groups have useful applications even to very simple systems like the 3-atom molecules that were illustrated. Please remember that interest in the subject matter of this article will not be confined to specialist mathematicians. Petergans (talk) 21:48, 16 March 2022 (UTC)


 * There are many infinite groups that can be understood by almost everybody. Among the simplest examples are the integers, the translations, the plane rotations with a fixed center, and the rigid motions. Your examples are cryptic, except maybe for experts in chemistry. Your section is also unsourced. So, as it is, your section is not convenient for Wikipedia. Moreover, even rewritten completely, it is definively misplaced as a subsection of "Finite groups". Rewritten as a section "Applications in chimestry", and correctly sourced, its inclusion could be discussed. However, as infinite groups are used in almost all sciences, I do not see any reason for such an emphasis on chimestry. D.Lazard (talk) 23:20, 16 March 2022 (UTC)


 * The section Group (mathematics) discusses infinite (discrete) groups in terms of combinatorial group theory and geometric group theory; applications in physics and chemistry are also mentioned. In particular there is a "see also" link at the beginning of the section labelled "Molecular symmetry", which discusses symmetries in the context of chemistry, that has been talking about. That link is probably the best place where content can be added, using the appropriate technical language. (Symmetries are also exploited in material sciences, now regarded as part of nanotechnology.) I had not noticed Petergans' background in chemistry at the University of Leeds; many apologies. Mathsci (talk) 01:15, 17 March 2022 (UTC)
 * Thank you. There is an extended treatment of group theory and applications in my book "Vibrating Molecules" (1971). Regarding citations: This is "common knowledge" in chemistry. For example, Chapter 12, "Molecular symmetry" in Physical Chemistry by Atkins & De Paula (pp 404-429 in the 8th edition, 2006) and half a dozen books cited at the end of that chapter. That's why this aspect needs to be mentioned on the main page concerning Group Theory. Also, it is logical that a section on infinite groups should follow the section on finite groups.Petergans (talk) 09:45, 17 March 2022 (UTC)
 * Well there's a already a two-sentence paragraph on chemistry, with three images & molecules. By comparison, infinite discrete symmetry groups also get short shrift (homotopy-theoretic mathematical genealogy?), cf Klein & Fricke, Coxeter, Magnus and Tits, with the well-known (2,3,7) reflection group relations $(gh)^{2}$=1, $(hk)^{3}$=1, $(kg)^{7}$=1 for image 4. Mathsci (talk)
 * I propose that this discussion move to talk:group (mathematics), so we don't keep pinging poor D. --Trovatore (talk) 16:01, 17 March 2022 (UTC)

Cona Methods
- Root finding (real/complex) - Dynamic Non-Linear System (generalized extension) - Finding Root of a Matrix A, or A^(1/n) (generalized extension)

The beautiful simplicity of the arithmetic structure (excluding derivatives) and the results will speak for itself. It will also be quite simple to verify that this is not a known or derivative method once you see and use the equation/method.

We are well aware of the Newton Liebniz controversies of the past and have well documented "discovery dates and methods" recorded at the US Copyright Office to insure proper attribution for our work.

Because we work in industry, not academia, the usual publication paths are not congruent. We believe the truth borne by the discovery, should not be withheld from the public domain. This would be disservice to science and truth. —Cona Methods (talk) 20:40, 14 April 2022 (UTC)
 * Apparently, you have not understood well what is the purpose of Wikipedia (see WP:WIKIPEDIA) and WP:What Wikipedia is not. If you read these two links, you will probably understand the reasons of my revert. Nevertheless, here are some more specific details.
 * Apparently, you have not understood well what is the purpose of Wikipedia (see WP:WIKIPEDIA) and WP:What Wikipedia is not. If you read these two links, you will probably understand the reasons of my revert. Nevertheless, here are some more specific details.
 * You assert that Cona method is new. So, it is original research. Wikipedia is not a place for publishing original research, as explained in WP:OR
 * You assert that Cona method has a beautiful simplicity. It is possible that this is true, but this is only your opinion, and you do not provide any way to verify it. In any case it it not the job of other editors to review your opinion. It is the role of reliable secondary sources. Without them, Wikipedia policy is to not talk about a result.
 * You have clearly a conflict interest here (see WP:COI). So if Cona method would pass the other criteria for inclusion in Wikipedia, it is not to you to add this inclusion.
 * So, Wikipedia is definitively not a place for publishing your own word. D.Lazard (talk) 22:09, 14 April 2022 (UTC)

Your last edits are vandalism, as they make my last post unreadable for other users. So, I have reverted them for restoring my post. On may talk page, as well as on other WP talk pages, you must follow the guidelines MOS:TALK, if you want to have an answer. Nevertheless, it is clear that the only goal of your edits is to promote your own work. This is definitively not allowed in Wikipedia. So, in the future, I'll answer to your posts only if it is clear that their goal is not to promote your work and your opinions. WP:Wikipedia is not a blog. D.Lazard (talk) 15:15, 15 April 2022 (UTC)




 * To be clear, it is only "new" in relation to the old 1700 mathematics of Newton. It was first published in 2019 under US Copyright confidentially. It was shared in confidence with members of the Applied Mathematics Dept at the University of Arizona. It represents a fundamental truth in mathematics and should be treated such in the public domain.
 * A this stage (prior to the github public equation/method release), verification for the skilled mathematician should be manifestly evident in the Root signatures computed (i.e. the fractal k update paths taken by the method) at the public domain: https://www.conamethods.com/
 * Mathematics represents concrete fundamental truths that can never be of opinion - including this discovery. The paper that was submitted to the copyright office is updated with new facts and will be shared via github https://github.com/f9analytics along with the underlying code that uses these methods.
 * The conflict of interest you assert works both ways, one who blocks mathematical truth, or one who chooses to share it in the public domain. What conflicts can ever arise from fundamental mathematics? A conflict between the zero and the 1?
 * Mathematics is not a word but a fact, so this assertion is misplaced.

Cona Methods (talk) 18:23, 15 April 2022 (UTC)

Barycentric Coordinates
Could you give me some information on why you removed my contribution for explicit conversions from Cartesian to Barycentric coordinates for tetrahedral? I thought as the 2-D versions are there, it would be useful to have them for tetrahedral — Preceding unsigned comment added by Ejricketts (talk • contribs) 22:29, 7 May 2022 (UTC)
 * The previous version of is far to be perfect, but your version is much worse, as it adds many issues. Here are some:
 * In a section that is devoted to describe barycentric coordinates on tetrahedra you start by supposing that these coordinates are known for doing other things
 * There is "tetrahedron" in the section heading, and the tetraedron appears only near to the end of your text
 * Some notations (for example $r$) are undefined, and some (for example $ri$ are used before being defined.
 * Your text contains large formulas that are almost unreadable, and this is not convenient for an encyclopedia.
 * Reading these formulas further, it appears that they are simply the instantiation of Cramer's rule and the definition of the determinant. This has nothing to do here. Moreover, this is only one of several methods for inverting a matrix, and you have not to impose your preferred method to the reader.
 * There are also style issues, but the above is definitively sufficient for a revert. D.Lazard (talk) 08:34, 8 May 2022 (UTC)
 * Thank you, I largely agree with the comments here. I hope you don't mind me asking as I only would like to better my writing.
 * I do think it is useful to have these formulas added, but they are quite long and not particularly readable. Ejricketts (talk) 09:10, 8 May 2022 (UTC)
 * Please, sign your posts in talk pages with four tildes ( ~ ).
 * Wikipedia is not a text book. So, for formulas (and other contents) that do not belong to the core of an article, it is better to use wikilinks, as I have done in the section for matrix inverse. D.Lazard (talk) 10:23, 8 May 2022 (UTC)

Re mathematics
You're apparently unfamiliar with WP:BRD and instead choose to characterize it as edit warring. Of course, your three reversions in the past two hours can't be similarly construed as edit warring, right? Be forewarned: if I initiate third reversion of your edits, which I'm all but prepared to do, you cannot again revert anything on the @Mathematics page for another 24 hours without being ipso facto in violation of 3RR. Instead, please use the @Mathematics talk page to explain why you disapprove of the changes to which User:Mgnbar and I agreed on a 2:1 consensus against you. Capiche? --Kent Dominic·(talk) 20:14, 22 May 2022 (UTC)

FYI
It is incorrect to write as a short summary a double group is a mathematical group.

As indicated in Double group, Talk:Double group and Articles for deletion/Double group, the topic "double group" refers to " character tables of finite subgroups of SU(2) ". This is 19th-century material which goes back to Klein in 1875 (the word binären) and Frobenius in 1899 (same word). As was apparent in the AfD, you did not appear to have slightest inkling about "double groups", although it was explained in that discussion. They apply to mathematics, theoretical physics (string theory), physics, material sciences (quasicrystals), and physical chemistry, etc, so not just physical sciences. Pierre Ramond has given a very good account of part of that theory in "Group Theory: A Physicist's Survey" (2010). From the AfD, your edits showed no knowledge of this area; nor has that appeared to change since the AfD. Some knowledge of projective representations, Schur multipliers, spin, character tables is required, i.e. engaging with WP:RSs. Three references are given in the lead (Griffith, Jacobs and Ramond): they all give reasonable accounts of double-valued representations, a.k.a. double groups. References to experts like Kostant, T. Springer, Steinberg, Macdonald, etc, give mathematical treatments that can be found in any treatments of Lie algebraic representation theory (e.g. Humpreys). The double group formulation first appeared in a quantum mechanics framework around 1930, by Bethe, Wigner, Weyl, von Neumann et al, with spin representations occurring as double-valued representations (or "ray representations"). If you are not familiar with this area, please check on WP:RSs; otherwise, it's unwise to edit in that area, if you don't know about it.

Repeatedly in the short description you have have suggested a double group is a mathematical group. That is unhelpful and misleading, and is alas incorrect. "double" is used to qualify "icosahedral group", so that the "double icosahedral group" is the "binary icosahedral group". The double-valued or spin representations of the icosahedral groups are just the ordinary representations of the binary group. Given that this topic is outside your expertise (as shown by the AfD), why are you attempting to edit in this area making misleading comments about binary groups? Mathsci (talk) 18:46, 26 May 2022 (UTC)


 * The short description is not aimed for specialists of the subject. I agree that I am not a specialist of group theory. However, if a professional mathematician with a good background in group theory cannot understand the lead of this article, this means that the lead does not follow the guidelines of the manual of style, and must be rewritten. In particular, if a double group is not a group (as suggested by your post) this must be clarified in the article.
 * Apparently, you have not understood the purpose of a short description (please, read and understand WP:Short description). Its only purpose it to tell readers whether the article is what they are searching for. As "group" has many non-mathematical meanings, it is essential that the short description says that the article is about mathematics. Because a large part of the article is about applications to physical sciences (this includes chemistry), this must be in the short description. Otherwise, some possibly interested people may miss this article. On the other hand, as "group" is already in the article, it is not useful to repeat it in the short description. This strongly limit the possibilities for a short description that respects the soft limit of 40 characters. As you do not like "mathematical group", I'll modify my previous tentative into . This is sufficient to allow readers to decide whether they want to read the article. D.Lazard (talk) 20:22, 26 May 2022 (UTC)


 * Of course the first statement above is correct. I am a retired University lecturer in chemistry with a long-term interest in the applications of group theory. I first created this article to fill a small niche gap, based on a chapter in Cotton's book "Chemical applications of group theory". There has been a long-standing issue with this user reverting my edits. He also reverted the title of the article a month after I had changed it from the original in order to avoid confusion with purely mathematical matters. The situation with multiple reversions is intolerable but it appears that there is nothing I can do about it. Perhaps together we might be able to do something to stop this mayhem? Petergans (talk) 08:41, 27 May 2022 (UTC)

Advice

 * if you believe that vanadalism is occurring please use WP:AVI where can report vandals. At the moment you are making disruptive edits making comments about material that appears to be outside your expertise.

That started with you being an OP for Articles for deletion/Double group, where you declared the topic of "double group" made no sense.

On the other hand, I was an invited speaker at an International Congress of Mathematicians, where I spoke amongst other things on projectuve representations; and before that, I won a prize of the London Mathematical Society for my work related to representations of the subgroups of SU(2).

So far on Talk:Double group, there is no record of any discussions by you. As explained in the mathematical footnote, which you have stubbornly refused to read, a double group Γ' is a group extension of a finite group Γ by {±1}, the cyclic of group of order 2. Thus a linear representation of Γ' is a projective representation with factor system or Schur multiplier in {±1}; equivalently it is a mapping of Γ into the general linear group which is a homomorphism up to a sign. As an algebraist you should know this; for example, it's in André Weil's Basic Number Theory and many other mathematical books.

At the moment you have previously stated that, as the OP at the AfD, "double group" made no sense (contrary to mathscinet) and have not engaged in discussion on talk:Double group. The material is straightforward. Mathsci (talk) 20:18, 7 June 2022 (UTC)
 * I'm sorry that you to have to read this abusive stuff. Has not the time come to ban a user who repeatedly ignores warnings and WP standards? N.b. your last warning has been deleted from talk:Double group by that user. Petergans (talk) 15:09, 12 June 2022 (UTC)
 * I am also preparing a notice to WP:ANI. Maybe, you may be interested in Administrators' noticeboard/IncidentArchive1045. D.Lazard (talk) 17:25, 12 June 2022 (UTC)

Spam?
Why did you decide my edit was spam? I added a published jouranl article about the topic in hand, that was accepted for publication in the American mathematical monthley, one of the world leading journals about expository mathematics. 195.113.30.150 (talk) 10:55, 20 June 2022 (UTC)
 * This citation is a spam since you inserted it for promoting its author; see WP:REFSPAM. Even if this would not be the case, it would not be acceptable as a source, because of WP:Reliable sources. Indeed, for being reliable, a mathematical article must have been published in a peer-refered publication, which is not the case of ArXiV. Even if this article would be regularly published, this does not means that it can be accepted in Wikipedia; for being accepted, it should be clarified which information, if any, is contained in it and is not in the other sources.
 * So, even if you did not added this reference in a promoting purpose, there were may reasons for reverting your edit.
 * Also, take care that edit warring may lead to block you for editing; see WP:3RR. D.Lazard (talk) 13:26, 20 June 2022 (UTC)
 * Did you bother to check? as written in the arxiv page, the paper is accepted for publication in the American mathematical monthly, the most popular mathematical journal in the world. It seems that you think you know better than the editors of the monthly. 195.113.30.150 (talk) 13:52, 20 June 2022 (UTC)

Revert of discussion of sum identity to 2x2 matrices
Hi D. Lazard,

I added a subsection to the sum subsection of the determinant article, on a specific identity relating to determinant of the sum of matrices for 2x2 matrices which you recently reverted.

I think it made a better fit there than under the 2x2 matrices section, particularly as there are few nice properties of sums of determinants so the identity highlights this special case and gives an application useful in theoretical physics.

It was probably bad style on my part to give it the same name as the section on 2x2 matrices.

I was wondering if I might add it back in, perhaps with some suggestions from you?

Thanks, Zephyr Zephyr the west wind (talk) 16:46, 25 June 2022 (UTC)


 * I am not against the addition of this formula. However this needs a clearer heading, a source, a reference for the proof (or a short proof). Moreover, the explanations that follow the formula are very obscure and must be clarified. Go on. D.Lazard (talk) 19:17, 25 June 2022 (UTC)
 * Perhaps a heading like 'Determinant of sum identity for 2x2 matrices'? I'm not sure of any sources, but I can certainly provide a short proof. In the absence of sources I'll leave out the comments afterwards, although I could provide an example using the Pauli matrices. Zephyr the west wind (talk) 22:23, 25 June 2022 (UTC)

User: ‎IpseCustos
There are strong indications that this user is the same one as user:mathsci, who was recently banned. I shall be grateful if you would look into this matter. Petergans (talk) 07:22, 26 June 2022 (UTC)
 * entries from this user first appeared in https://en.wikipedia.org/wiki/User_talk:Petergans just after mathsci was banned. (Section double group again)
 * the content of those messages continues where mathsci left off before being banned
 * some recent posts by this user on my talk page are unintelligible. For example, I've never heard mention of "spin(3)" before and can't imagine what it is.
 * the tag recently added to double group "See also" by this user does not make sense.
 * I do not believe that IpseCustos could be a sockpuppet of Mathsci. The fact that they began to edit just after the ban may easily be explained by the fact that, before the ban, it was impossible to discuss reasonably about the content of the article. Also, while Mathsci never discussed the point, IpseCustos really discusses the article content. I cannot imagine that Mathsci could be able to change so dramatically his behavior. Said otherwise, I disagreed almost always with Mathsci's posts and I often agree with IpseCustos concerns, and when I disagree, a compromise is generally clearly possible.
 * If you do not know of spin(3), then follow the link. Reading this article convinced me that the lead of double group should contain something like . D.Lazard (talk) 09:20, 26 June 2022 (UTC)
 * I believe the term is used only for those subgroups of Spin(3) that contain the involution element. Equivalently, a double group is a subgroup of Spin(3) of even order. IpseCustos (talk) 18:13, 26 June 2022 (UTC)

Field
I'll be back tommorow, try to be constructive, as there already ate errors on the page you could fix. Thanks! 49.185.41.241 (talk) 14:33, 29 June 2022 (UTC)
 * If there are errors in the article you had better to fix them yourself, or tp point them in the talk page of the article instead of introducing new errors. One of the reasons of the policy  MOS:VAR is that large scale change as you did are error prone for a weak improvement. Also, even without errors, your changes are controversial, since there is no consensus on Wkipedia for preferring blackboard bold to usual bold. See MOS:BBB. D.Lazard (talk) 15:18, 29 June 2022 (UTC)

Symmetric matrix
I struggled a long time with the article quadratic form, before I finally understood why the matrix is symmetric. I thought I would make it easier for other readers by adding an example of how the matrix is constructed. Would you mind looking at what I did?

In any case, thank you for your many contributions to Wikipedia. Comfr (talk) 04:09, 2 July 2022 (UTC)


 * I'll look on your edits. In any case, quadratic form is in my watchlist. D.Lazard (talk) 07:55, 2 July 2022 (UTC)
 * You wrote something I can understand. I like the way you write.  Thanks again for your many contributions to wikipedia.  Comfr (talk) 18:09, 2 July 2022 (UTC)

Glossary of Areas of Mathematics
Great to see you are active on glossary of areas if mathematics, but would you mind including inline references to your adjustments? Especially after you've tagged it as not having references. It's fine to disagree on an entry, but to edit a referenced entry to what you feel is better, and leave the old inline reference there is confusing. If you check the reference on the term "analysis", it clearly doesn't say what you've edited the entry to say. If you want to dispute references thats fine of course, but do it properly please. Brad7777 (talk) 21:52, 3 July 2022 (UTC)

That should be glossary of areas of mathematics Brad7777 (talk) 21:53, 3 July 2022 (UTC)
 * It is not what I feel better. It is what says the first sentence of the linked article (with two sources). For coherence, and for not confuse readers, this list must not contradicts the linked article. In any case, you source clearly does not support your definition of analysis. I'll restore my formulation with a better source, whose title suffices to support most of my wording. D.Lazard (talk) 08:03, 4 July 2022 (UTC)
 * Thanks for putting the care into this project, and providing a source Brad7777 (talk) 08:35, 4 July 2022 (UTC)
 * FWIW The source I provided does actually say limits of sequences are the foundational concept of mathematical analysis, on page 29. Please bother to look, and not lie. Brad7777 (talk) 08:37, 4 July 2022 (UTC)

That's in Courant, Richard (1961). "Differential and Integral Calculus Volume I", Blackie & Son, Ltd., Glasgow. (You are better than liar, so don't lower yourself to one) Brad7777 (talk) 08:42, 4 July 2022 (UTC)

Comprehension
D.Lazard, you've stated your English level is intermediate, and's it's clear that certain parts of this website, your English is not good enough for. You've completely miscomprehended the meaning of "Modern Analysis: a modern approach to advanced calculus." An approach in this context refers to a methodology, not a basis of  meronym-holonym relationships. Please source your adjustments. That's not difficult to comprehend. Brad7777 (talk) 11:19, 4 July 2022 (UTC)

Complex Exponentiation.
David,

I see that you undid my edit, adding a 3rd example to the intricacies of complex exponentiation.

Why did you do so.

I've posted a tech note on this topic at http://kirkmcd.princeton.edu/examples/1tox.pdf

--Kirk McDonald Kirktmcdonald (talk) 15:16, 20 July 2022 (UTC)


 * Kevin (this is as close to your first name as is David to mine),
 * One of the main policies of Wikipedia is WP:OR, which asserts that original research is forbidden in the articles. So, I have removed your post as it is clearly your own original research. D.Lazard (talk) 16:27, 20 July 2022 (UTC)
 * Daniel (sorry for previously typing David),
 * The topic "Can 1^x = 2?" is the subject of a YouTube video,
 * https://www.youtube.com/watch?v=9wJ9YBwHXGI
 * and apparently is being discussed in many math classes around the world, with generally confusing explanations being given.
 * My post (deleted by you) was not so much "original research", as an attempt to show that material already on the Exponentiation Wiki page has good, direct application to this apparently confusing problem.
 * It is a shame if the policies of the Wiki prevent it from helping "students" on such issues.
 * If I were to add a link to the above YouTube video, would my post then satisfy the WP:OR policy?
 * --Kirk Kirktmcdonald (talk) 20:33, 20 July 2022 (UTC)
 * Daniel,
 * Many Wiki pages use YouTube, and other social media as sources. This is the way of the 21st century.  Your rigid rules, that exclude social media, are making Wikipedia irrelevant to contemporary thought.
 * No wonder that Wikipedia is apparently failing financially, and may soon disappear. Kirktmcdonald (talk) 06:15, 22 July 2022 (UTC)
 * No wonder that Wikipedia is apparently failing financially, and may soon disappear. Kirktmcdonald (talk) 06:15, 22 July 2022 (UTC)

Regarding the revert in Pi article
I agree that my edits didn't make justice to the concept of Pi is constant. Could you write about the property? I think that it's one of the most important concepts about Pi. Northeast heritage (talk) 09:03, 26 July 2022 (UTC)


 * The fact that any two circles are similar is relevant for the articles on circles and on similarity, not
 * for the article on Pi. D.Lazard (talk) 11:50, 26 July 2022 (UTC)
 * I believe that proof of the fact that Pi is constant is important in Pi article. Anyway thanks for reply. Northeast heritage (talk) 11:53, 26 July 2022 (UTC)

Inconsistent fonts
Hi User:D.Lazard. It puzzles me why you prefer to confuse the hapless reader by insisting on inconsistent fonts in the article on Tensor products. As I see it, throughout Wikipedia the LaTeX markup form $$·$$ is to be preferred. I think clarity and ease of reading for the reader outweigh ease of writing for the editor.Chjoaygame (talk) 23:08, 25 September 2022 (UTC)


 * It is true that the latex markup is generally preferred for formulas that are not very simple, but, for isolated variables, math or mvar are often preferred because of a better vertical alignment (strongly improved over the time) and less computer charge of Wikipedia servers. However the manual of style MOS:FORMULA is clear, both versions are acceptable, and one must not change from one style to the other without strong reasons. This is the first reason of my revert.
 * Another reason of my revert was that the change of style may have unexpected side effects. In particular, when one hovers above an article link, the first paragraph of the article is displayed in a popup window, in which formulas are not correctly displayed. I remembered that html was correctly displayed, but latex was not displayed at all. My memory is wrong or things have changed: presently, formulas using the math template are not displayed at all, and, for latex formulas, this is the latex source that is displayed. So, when possible, formulas must be avoided in first paragraphs.
 * This, and the bad font of the html $v$, make that I will do nothing if you revert my revert. D.Lazard (talk) 09:08, 26 September 2022 (UTC)


 * Thank you for your reply. I am not on a crusade to 'fix the fonts', so I will let sleeping dogs lie.


 * Yes, lately there have arisen various annoying disorders of font displays. I have an impression that there have been some subsequent ameliorations of these.


 * Yes, in general one should not put formulas in the lead.Chjoaygame (talk) 12:08, 26 September 2022 (UTC)

some questions on the Orthogonal Group page talk group
Hi, I have put some questions in the talk page of the wikipedia article on the "Orthogonal group". I am notifying it to you as I saw you rather active in the discussions and maybe you have and idea une musque de Biscaye (talk) 11:02, 29 September 2022 (UTC)

thanks by the way:) une musque de Biscaye (talk) 11:02, 29 September 2022 (UTC)

Recent edit to Talk:Exterior algebra
You recently moved a notelist-talk template from the end of Talk:Exterior algebra to the end of a paragraph containing a efn template, The reason that I initially placed it at the end was so that if later edits contained notes, they would be grouped at the end of the section.

A secondary consideration is the indentation level of the notes. With the new location, the note is at the left margin and interrupts the flow of the edits. Shmuel (Seymour J.) Metz Username:Chatul (talk) 12:05, 29 September 2022 (UTC)

Your revert on Algebraic operation
Hi, can I ask why you reverted my edit on Algebraic operation? As far as I can see, it doesn't change the final formatting on the page, but it does fix two "missing end tag" Linter errors. --rchard2scout (talk) 13:32, 5 October 2022 (UTC)
 * This was an error, and I self-reverted this edit. Apparently the page was not correctly displayed because of a transmission error, and I did not checked the origin of the error. D.Lazard (talk) 13:47, 5 October 2022 (UTC)
 * I understand, thanks for the self-revert. Happy editing! --rchard2scout (talk) 13:49, 5 October 2022 (UTC)

The file revert from Circular arc
Hello, I would like to understand what's the problem with my SVG file ? You call it "confusing" but the different parts are distinguished by color. You say it does not improve the article, but I made this file because there wasn't any file about minor and major arcs on Wikimedia Commons. Can you provide arguments as to why the file shouldn't appear ?

BloomyFractal (talk) 15:07, 11 October 2022 (UTC)


 * There are several reasons for the revert, which include:
 * The image contains textual information. This must be avoided since it cannot be modified without changing the image; see MOS:TEXTASIMAGES. Instead, the textual explanations belong to the caption.
 * The image uses notations that are not defined in the article.
 * There are four arcs that are drawn; two of them are confusing
 * The unusual names of the circle points may be confusing.
 * The measure of the arcs in degrees adds confusion, as arcs are defined independently from angle measures.
 * A good image would consists of a circle with two points called, say, A and B, with the corresponding radiuses drawn in black. The two arcs must be colored in differents colors. The caption could be . Every other information must be in the body of the article.
 * If you are able to produce an image of the same or higher quality than the existing one, it should replace the existing one, not placed after it (readers are not supposed to think about the differences of two similar images). D.Lazard (talk) 17:44, 11 October 2022 (UTC)

Revert on Square number
Why was my edit reverted on Square number with an edit message of ? 158.165.7.175 (talk) 14:48, 19 October 2022 (UTC)
 * "is considered to be" is an opinion of someone; "is called" means a standard definition. This is not the same, and your edit was misleading and wrong. D.Lazard (talk) 15:04, 19 October 2022 (UTC)
 * Alright, got it, my bad. Please don't assume bad faith from IP editors though :) 158.165.7.175 (talk) 16:12, 19 October 2022 (UTC)
 * No problem; it was clear from the beginning that it was a good faith edit. D.Lazard (talk) 16:15, 19 October 2022 (UTC)

change in quadratic form
Many people read in nocturnal dark mode, so I think that all edits should respect this fact, and special care should be taken with mathematical expressions. There are lots of mathematical pages which are unreadable in nocturnal dark mode.. Think also that in many countries in winter most of the time is night, moreover, dark reading modes save energy and also they emit less CO2 to the atmosphere ¿still you think is not worth the change I proposed? Altasperlas (talk) 14:45, 14 November 2022 (UTC)
 * This is not a reason for changing the layout of the article, as you did. In any case, this seems a general problem of either your browser or of the Wikipedia software. This is a very bad idea to try solving it by editing each of the millions of Wikipedia articles. The best thing is to submit your problem to WP:Village pump. D.Lazard (talk) 16:42, 14 November 2022 (UTC)


 * Thanks for your suggestion, I have done it, I have just posted an issue on the technical part of the page you recommend me. Hope it helps. We will see. Altasperlas (talk) 08:27, 15 November 2022 (UTC)

"Invertible element" listed at Redirects for discussion
An editor has identified a potential problem with the redirect Invertible element and has thus listed it for discussion. This discussion will occur at Redirects for discussion/Log/2022 November 18 until a consensus is reached, and anyone, including you, is welcome to contribute to the discussion. UltimateDude101 (talk) 19:59, 18 November 2022 (UTC)

Euler's totient funcion
Hi, i understand your reasons to undo my corrections about one of the proofs of the page, but the proof written before mine is wrong... JuanPV78 (talk) 23:08, 26 December 2022 (UTC)


 * My proof is the right ones. Maybe it can be writed with another terms or in a more easy way, but coming back to the old proof is not a right desicion for me.
 * I'm just looking for the excellence of Wikipedia, greetings from Argentina JuanPV78 (talk) 23:13, 26 December 2022 (UTC)
 * I agree that the proof is wrong. I removed it since it was the only proof in the section. D.Lazard (talk) 16:31, 27 December 2022 (UTC)
 * Oh, i saw it... Great! I agree with you now 🙂👍🏾
 * May be we can add 'a \neq 1' if you want... 🙈🙂 JuanPV78 (talk) 19:19, 27 December 2022 (UTC

Edits
Hi D.Lazard, would you please undo the reversing of my edits? I was editing my own message to give a better understanding. Alexmov (talk)
 * As said in my edit summary, and in WP:TALK it is not allowed to edit your own posts when somebody has already replied. Moreover, your way of writing very long posts, and editing them many times is time consuming for other editors who have to spent time for checking the differences. This can be qualified as WP:disruptive editing, and may lead to an edit block, if you continue after being warned. D.Lazard (talk) 15:30, 1 January 2023 (UTC)


 * You were the only person that replied Alexmov (talk) 19:03, 1 January 2023 (UTC)
 * You like making friends. Don't you.  Alexmov (talk) 19:39, 1 January 2023 (UTC)

Dabs on Proposition
Thanks for sorting the link to linguistic expression on Proposition. Could you also sort the links to dab pages: Possible & Characteristic set in the "Semantic characterization" section on that article?&mdash; Rod talk 18:38, 3 January 2023 (UTC)

What creeps women out
Please stop watching my talk page. It is creepy. Your threats and/or input are not welcome and I have deleted them. Alexmov (talk 07:56, 5 January 2023 (UTC)

What is a tensor?
Why did you revert my edit?
 * This is explained in the edit summary. D.Lazard (talk) 16:53, 6 January 2023 (UTC)


 * The sentence has the word array pointing to a definition of an array data structure as defined in CS.  Thus, saying that a tensor is stored in an array seems reasonable.  Personally, I would draw a sharper distinction between data stored in an N-way array and a tensor that is stored in an N-way array.   Alexmov (talk) 18:24, 6 January 2023 (UTC)

Dealing with disruptive editors?
I added level 1 warning templates for WP:AGF and WP:CIV in Tensor to User talk:Alexmov, which he deleted. What is the proper protocol at this point? Thanks. Shmuel (Seymour J.) Metz Username:Chatul (talk) 18:44, 6 January 2023 (UTC)


 * There are two ways. The first one is to submit a request to WP:ANI for an edit block motived by WP:NOTTHERE, WP:disruptive editing and WP:CIVILITY. It is for preparing such a request that I warned this editor formally (see the history of her talk page). However, this is time consuming, and would result probably into a short term block.
 * The second way, the one that I prefer, is to not answering to her posts on talk pages, and to wait that she becomes tired to discuss against nobody. This implies that her edits of the main space must be scrutinized and reverted when they are not clear improvements. For example, two of her three last edits of Tensor are typo corrections and deserve to be kept, while I have reverted the last one. D.Lazard (talk) 21:08, 6 January 2023 (UTC)

Edit reverse
Respected sir, today I made and edit on Wikipedia partition numbers and you reversed it without having any mathematical flaw. Can I know what's the reason behind it? John2900 (talk) 10:44, 8 January 2023 (UTC)


 * For editing Wikipedia, you must respect Wikipedia rules, in particular, those explained in WP:OR and WP:RS. D.Lazard (talk) 11:50, 8 January 2023 (UTC)

Edit reverse to the Tensor Article
Please read the edit summaries before reversing edits. As I explained in the edit summary, the letter n was refering to the number of components. Hence, one needed a different letter to represent number of modes. I choose letter M. Alexmov (talk) 01:46, 11 January 2023 (UTC)


 * If you did not like the capital M, you could have changed it lower case m. Instead, you chose to revert the edit. Why?   Alexmov (talk) 04:56, 11 January 2023 (UTC)

JuanPV78
It seems has reported you to WP:RFC/NAME without properly notifying you. They didn't provide a valid reason, instead complaining about a content dispute. I'm surprised they came to RFC/NAME of all places. - ZLEA  T \ C 04:57, 20 January 2023 (UTC)

Hello
Hello sir.Why did you revert my edit? I just asked a question. please reply. Mohammad.Hosein.J.Shia (talk) 05:48, 20 January 2023 (UTC)
 * The above relates to edits at Euler's totient function. See the report at Administrators' noticeboard. Johnuniq (talk) 06:30, 20 January 2023 (UTC)
 * I made 2 reverts of 3 's edits, with edit summaries (for the revert of the 2 first edits) and  for the last one. I thought that this explains sufficiently my reverts. Here are some more details.
 * "Proofs are not distinguished from assertions": Mohammad.Hosein.J.Shia edited proofs in a bulleted list of assertions, by added one proof and modifying another one. As there were no proof for the other assertions of the list I have eventually removed all the proofs.
 * "Unexplained and badly formatted changes": This consists of changing "m" to "n" (unexplained), and creating a pair of formula that is rendered as a single formula: $$n \mid \varphi(a^n - 1) \quad $$ ( $$n, \ a \in \mathbb{N}$$, $$a \geq 2$$ ). This is badly formatted; moreover readers are not supposed to understand (without prose) the meaning of the parentheses. D.Lazard (talk) 10:44, 20 January 2023 (UTC)

Hi Mr. D.Lizard
Your contributions to the English Wikipedia in the field of mathematics is amazing and I would personally would like to thank you for your contributions. If it is not a big ask, would you make the same miracles to Simple English Wiki? Thank you for reading this. - S L A Y T H E - (talk) 13:48, 24 January 2023 (UTC)


 * Thanks for the comment and the suggestion. If I would have timefor working another wiki, it would be the French Wikipedia. D.Lazard (talk) 18:33, 24 January 2023 (UTC)

"Singulairty of an algebraic variety" listed at Redirects for discussion
A discussion is taking place to address a potential problem with the redirect [//en.wikipedia.org/w/index.php?title=Singulairty_of_an_algebraic_variety&redirect=no Singulairty of an algebraic variety] and it has been listed for discussion. Anyone, including you, is welcome to participate at until a consensus is reached. 1234qwer1234qwer4 09:09, 8 February 2023 (UTC)

e (Mathematical Constant)
It may be that the consensus is to change it to e (Number). I cannot understand why anyone wants to add confusion but that's life. If it gets changed, I'll put in a request to change it to e Constant. Is there any mileage in suggesting e Constant as an alternative to e (Number) before the consensus? Also should action be taken about the deliberate misinformation put forward by User:Fgnievinski? OrewaTel (talk) 02:06, 19 February 2023 (UTC)

Proposed deletion of Order of a polynomial (disambiguation)


The article Order of a polynomial (disambiguation) has been proposed for deletion&#32;because of the following concern: "Nothing links here now; I changed all (three) links to Order of a polynomial, which describes the various meanings in detail."

While all constructive contributions to Wikipedia are appreciated, pages may be deleted for any of several reasons.

You may prevent the proposed deletion by removing the notice, but please explain why in your edit summary or on the article's talk page.

Please consider improving the page to address the issues raised. Removing will stop the proposed deletion process, but other deletion processes exist. In particular, the speedy deletion process can result in deletion without discussion, and articles for deletion allows discussion to reach consensus for deletion. Zaslav (talk) 08:45, 19 February 2023 (UTC)
 * Per as WP:INTDAB, the intensional links to a disambiguation page must pass through a page with the suffix "(disambiguation)". Therefore, I have not only removed your PROD tag, but I have also reverted your edits of intensional links to this dab page. D.Lazard (talk) 10:11, 19 February 2023 (UTC)

Revert on an edit of fundamental thm
Concerning revision: https://en.wikipedia.org/w/index.php?title=Fundamental_theorem_of_calculus&oldid=1141507046

The purpose of this addition is to give a proof in the level of details that is more suitable for readers with some mathematical training which can benefit from a short paragraph. Please specify what do you mean by "Unsourced". Specifically, where do you think sources are needed. Gilgoldm (talk) 14:42, 27 February 2023 (UTC)
 * As several steps of your proof are only sketched, a reference to a reliable source is required for allowing readers to verify your proof. In any case, your proof is too technical for most readers, as using knowledge on small o notation and its properties. If lacking details would be provided, your proof would be longer than the first proof (from which I removed the confusing verbosities). Also, if details are provided, your proof is not really different from the first one; so it is not useful, even for trained readers. D.Lazard (talk) 16:57, 27 February 2023 (UTC)