Talk:Al-Jabr

al-Jabr
The explanation of the al-Jabr operation cannot be correct:

The al-Jabr operation is subtracting a quantity from one side of the equation and adding it to another.

Applying this to:

a = b + c

gives:

a + b = c

Which is clearly inconsistent. Someone with more expertise on this book needs to substitute the correct definition of what the al-Jabr operation was. Furby100 22:07, 2 February 2006 (UTC)
 * Fixed some time ago. Mukadderat 23:53, 26 March 2006 (UTC)

Unsolvable cases
Does anyone know whether al-Khwarismi had any consideration of "unsolvable" cases like $$x^2 + 4 = 0 $$, not covered by the 6 solvable cases? Mukadderat 23:53, 26 March 2006 (UTC)

al-Khwarizmi does not cover them, but such equations occasionally appear in later algebraists, such as Ibn al-Ha'im and al-`Amili. ---Jeff Oaks

Title, al-jabr, al-muqabala
Before I give some brief comments on this article, I want to say that the errors are not those of the author, but of the secondary sources he/she used.

This article has many errors. The first is that "al-mukhtasar" in the title of al-Khwarizmi's book does not mean "compendious", but is better translated as "condensed", "brief", or "abridged". Also, "al-jabr wa'l-muqabala" was the medieval name for the art of algebra, so the title is better rendered "The condensed book on algebra".


 * That is exactly what "compendious" means, though in modern times it is often confused for a synonym of "encyclopaedic". Hv (talk) 01:52, 19 January 2008 (UTC)

The book does not provide algebraic and geometric solutions to the 6 types of equation. It gives a numerical recipe for the solution, and then offers geometric proofs that the method is valid.

The three types of algebraic number were mal (literally "sum of money", "treasure", etc., for our x^2), jidhr (lit. "root" for our x), and `adad mufrad ("simple number"). In the worked out problems shay' ("thing") was usually used in place of jidhr, and simple numbers were counted in dirhams, a unit of currency. Later algebraists substituted `adad ("number") or ahad ("unit") for dirham.

Regarding the operations al-jabr (restoration) and al-muqabala (confrontation), see my article "Simplifying equations in Arabic algebra" (with Haitham Alkhateeb) in an upcoming issue of Historia Mathematica. The article is already available online:

http://authors.elsevier.com/JournalDetail.html?PubID=622841&Precis=DESC (click on "tables of contents and abstracts")

Medieval mathematicians had no concept of negative numbers. In an expression like "ten less a thing" (10 - x) both the 10 and the x are positive. Do not confuse the simple idea of subtracting positive numbers with the existence of negative numbers. Further, for them "ten less thing" (10 - x) was thought of as a deficient ten, which has had x removed from it. The operation has already been carried out. In an equation like 10 - x = x^2 (ten less a thing equals a mal) one is instructed to "restore" (ajbir, conjugated from al-jabr) the deficient 10 to make it a full 10. Then an x needs to be added to the other side of the equation. This is a two-step process.

Al-muqabala means "confrontation". In an equation like 2x + 10 = 5x the 2x and the 5x are "confronted", which entails bringing them face-to-face and taking their difference.

For a good overview of Arabic algebra, see Ahmed Djebbar's 2005 book _L'algèbre arabe : Genèse d'un art_.

---Jeff Oaks
 * I could not find the article at the link, and Googling only showed links to pay $34 to see the article. Nicknicknickandnick (talk) 09:14, 24 October 2010 (UTC)
 * The article seems to be . The website seems to say it is now openly available. 130.243.83.87 (talk) 18:06, 13 February 2014 (UTC)

There has been put forth another exlplanation for the term "algebra". In his book, "The Worlds of Medieval Europe", Clifford Backman suggests that this book was so influencial, that it was called, simply, The Book. In Arabic, this is al-jibra.MarkieAA (talk) 13:43, 30 August 2008 (UTC)

Syncopation
The main article uses the term "syncopation", as in "none of the syncopation found in greek, etc." I am not familiar with this sense of the term "syncopation". Does the author mean "formula", "abbreviation"? Katzmik 13:24, 29 July 2007 (UTC)
 * Hopefully this will answer your question:

Boyer (1991). "Revival and Decline of Greek Mathematics", p. 178, 180-182....The chief difference between Diophantine syncopation and the modern algebraic notation is the lack of special symbols for operations and relations, as well as of the exponential notation....  ...Throughout the six surviving books of Arithmetica there is a systematic use of abbreviations for powers of numbers and for relationships and operations. An unknown number is represented by a symbol resembling the Greek letter ζ (perhaps for the last letter of arithmos)....
 * You may also want to study the following article in order gain a better understanding of the differences between rhetorical, syncopated, and symbolic algebra: History of algebra. I hope that this helped. selfworm Talk ) 14:39, 29 July 2007 (UTC)

Yes, thanks. I do not believe this is a widely known meaning of the term, but rather a technical term with a special meaning in this area, much as the term "field" in algebra has special meaning. Perhaps a link should be provided in the body of the main article. Katzmik 10:24, 30 July 2007 (UTC)

Where is the book?
I cannot find the original manuscript of The Compendious Book on Calculation by Completion and Balancing in the same way that Philosophiæ Naturalis Principia Mathematica is available both for sale and for free.--71.118.39.70 (talk) 23:08, 15 July 2008 (UTC)


 * According to (Jeffrey A. Oaks, Haitham M. Alkhateeb, "Simplifying equations in Arabic algebra", Historia Mathematica Volume 34, Issue 1, February 2007, pp. 45–61.), published Arabic editions are:
 * Al-Khwārizmī, 1831. The Algebra of Mohammed ben Musa. (Translated and edited by Frederic Rosen.) London. Reprinted as Islamic Mathematics and Astronomy 1 (1997). The series Islamic Mathematics and Astronomy is published in Frankfurt am Main by the Institute for the History of Arabic–Islamic Science and the Johann Wolfgang Goethe University. [ISBN 3-8298-4001-2]
 * Al-Khwārizmī, 1939. Kitãb al-mukhtaṣar fī ḥisāb al-jabr wa’l-muqābala. (Edited by ‘Alī Muṣṭafā Musharrafa and Muḥammad Mursī Aḥmad.) Dār al-Kātib al-‘Arabī, Cairo. Reprinted in 1968.
 * I'm just reproducing the information as given in the article. Here is a web page listing all publications in the series Islamic Mathematics and Astronomy, including the one referred to above. There is a recent reprint of Rosen's translation (ISBN 978-1402100543), but as far as I can see it does not contain the source text; and as it is claimed to be a facsimile reprint of the 1831 edition, I have some doubt that the issue Islamic Mathematics and Astronomy 1 contains the Arabic text. --Lambiam 09:12, 22 July 2008 (UTC)

Since I wrote that article Roshdi Rashed has published a critical edition of al-Khwarizmi's book, using all known manuscripts (the Oxford MS is not unique). He includes a French translation and a commentary. While I do not agree with some of his commentary, the edition and translation are good:

Al-Khwarizmi: Le Commencement de l'Algebre. Texte etabli, traduit et commente par Roshdi Rashed. Paris: Blanchard, 2007.Jeff Oaks (talk) 19:38, 18 October 2008 (UTC)

Where is the original manuscript written by Al-Khwarizmi located? In a museum somewhere? Only the translations of the original manuscript are mentioned in the article. Please add the current location of the original book written in 820 ACE to the article. —Preceding unsigned comment added by Scraniel (talk • contribs) 11:13, 13 February 2010 (UTC)


 * Just wandering about looking for news about the middle east via www.aljazeera.com I ran into the " 1001 inventions " here: http://www.1001inventions.com/1001inventions/academic-sources/manuscripts . I'm sure you could contact them and ask about its "provenace" or history, i.e. just how old it is:
 * •Al-Khwarizmi: ‘Kitab al Mukhtasar fi’l Hisab al-Jabr wal-Muqabala’, or ‘Compendious Book of Calculation by Completion and Balancing’ (Algebra).
 * A copy of this book is kept at the Princeton Unviersity Library, New Jersey, USA (library.princeton.edu)


 * My assumption is that there is no "original" original but, rather, multiple copies exist each with their own slight variations because they were hand-copied. Don't be surprised if you find out that the original original is long-gone. Bill Wvbailey (talk) 01:30, 1 March 2011 (UTC)


 * Did this book survive only in the Latin West? I believe I've heard that mentioned somehwere, but I can't recall the source. If that is the case, then that deserves a mention in the article. Abvgd (talk) 22:02, 31 October 2012 (UTC)

Negative quantities
The Arabic word al-jabr is said in the article to be the operation of "moving a negative quantity from one side of the equation to the other side and changing its sign."

Negative numbers were not acknowledged by medieval mathematicians. In an expression like "ten less a thing" (10 - x), both the "ten" and the "thing" were positive quantities, the latter subtracted from the smaller. The whole expression was considered to be a deficient 10 (since a "thing" has been removed from it). In an equation, one "restores" (al-jabr means "restoration") the ten, and adds the "thing" to the other side of the equation to maintain equality. The word "al-jabr" was also used in Arabic mathematics outside the context of algebra to "restore" deficient quantities.

See my article (with Haitham Alkhateeb) "Simplifying equations in Arabic algebra", Historia Mathematica 34 (2007), 45-61.Jeff Oaks (talk) 19:53, 18 October 2008 (UTC)


 * All of you (f.ex. User:MarkieAA above) who refer to proprietary articles: we are the poor ones giving away articles for free, and some of us don't have access to those articles, neither the economical means to get it. If you want to advertize your articles, why don't you do it by improving Wikipedia's article yourself? It would be a nice gesture of goodwill. ... said: Rursus (bork²) 10:49, 19 January 2009 (UTC)


 * I've tried to fix this up a bit, based on Katz, and a bit on the above. However, I'm not sure how discussing "10 - x" fits with Katz assertion that all coefficients had to be positive William M. Connolley (talk) 21:25, 31 March 2011 (UTC)

Title
I agree with Jeff Oaks above that this is a very poor title. Is Compendious Book even good writing? We would normally say Compendium in modern English for such cases. WP:COMMONNAME would suggest that the title should be Al-jabr.  Spinning Spark  12:05, 22 October 2013 (UTC)

Length
How many pages did it originally run? -- Beland (talk) 00:16, 23 December 2018 (UTC)

Requested move 25 October 2023

 * The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: moved. I am willing to reconsider per WP:RMCI if presented with evidence that this book is not the WP:PRIMARYTOPIC for Al-Jabr. (non-admin closure) Rotideypoc41352 (talk · contribs) 11:19, 2 November 2023 (UTC)

The Compendious Book on Calculation by Completion and Balancing → Al-Jabr – WP:COMMONNAME, instead of an exceedingly clunky full calque, see the historical talk page discussion Remsense  聊  10:30, 25 October 2023 (UTC)
 * Support: Yes, it's pretty clunky, and frankly no more natural/recognisable than the Arabic name, which is at least concise and has the merit of sounding like Algebra, which is vaguely instructive. Also per Ngrams. Iskandar323 (talk) 10:54, 25 October 2023 (UTC)
 * Iskandar323, much closer than i assumed, i confess! how much do you think the Wikipedia article affects this? — Remsense  聊  11:46, 25 October 2023 (UTC)
 * Given the dates involved, and the take-off of the Ngrams numbers specifically in 2005, when this article was created, I would say a lot. But I think the WP:CONCISE argument is the main course here. Iskandar323 (talk) 12:12, 25 October 2023 (UTC)
 * Is not the main application of "Al-Jabr". At least in Persian, there exists many books entitled "Jabr", written by other authors. Hooman Mallahzadeh (talk) 12:01, 25 October 2023 (UTC)
 * What's the most famous book, and what are its English-language results? Iskandar323 (talk) 12:40, 25 October 2023 (UTC)
 * @Iskandar323 The name of book is not complete, it is too abstract. I propose to move article title to "Al-Jabr wal-Muqābalah". Both parts, the part "Jabe" and part "Muqābalah" should be mentioned. Hooman Mallahzadeh (talk) 12:54, 25 October 2023 (UTC)
 * @Iskandar323 Even in Arabic الجبر is ambiguous. It does not refer to الجبر و المقابله book uniquely. In English "Al-Jabr" is small enough but is ambiguous too. This trade-off (small-ambiguous) is not good! Hooman Mallahzadeh (talk) 13:30, 25 October 2023 (UTC)
 * It doesn't really matter what it means in Persian or Arabic - we are concerned here with what it means in English - are there other routinely called "Al-Jabr" in English-language texts? It is often referred to as just "Al-Jabr" in scholarly texts,, but I am ready to be convinced that there are other competing meanings, or that there may be different combinations of different parts of the Arabic name that way work better. Iskandar323 (talk) 17:35, 25 October 2023 (UTC)
 * I would say Capital or Analects are equally vague titles, but they do just fine. Remsense  聊  17:36, 25 October 2023 (UTC)
 * Notified WikiProject Books,  WikiProject Arab world, and  WikiProject History of Science. —  Remsense  聊  20:50, 28 October 2023 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.