Wikipedia:Articles for deletion/Dao's theorem


 * The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review).  No further edits should be made to this page.

The result was   delete. non of the keeps are policy based Secret account 15:57, 18 October 2014 (UTC)

Dao's theorem

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This is more of a request for discussion than a request for deletion. the subject of this article is beyond me, however based on the creators editing history I feel like this article is an attempt to promote his own currently non notable theorem Jac 16888  Talk 11:15, 28 September 2014 (UTC)


 * Comment As of now the article is just "theorem + eponymous person + theorem text", lacking a credible claim of significance. For starters, explain briefly what notable purpose this theorem can serve, like what big problem can be solved or benefited by this.  野狼院 ひさし  Hisashi Yarouin 13:39, 28 September 2014 (UTC)


 * Note: This debate has been included in the list of Science-related deletion discussions. NorthAmerica1000 15:19, 28 September 2014 (UTC)


 * Note: This debate has been included in the list of People-related deletion discussions. NorthAmerica1000 15:21, 28 September 2014 (UTC)


 * Note: This debate has been included in the list of Vietnam-related deletion discussions. NorthAmerica1000 15:21, 28 September 2014 (UTC)  — Preceding unsigned comment added by Eightcirclestheorem (talk • contribs)

--Eightcirclestheorem (talk) 14:56, 28 September 2014 (UTC)


 * Please do not add the article content here Dao, it is not what this page is for. The issue is that you have created this theorem, and now you appear to be using Wikipedia to promote it, that is not what Wikipedia is for, see WP:PROMO, WP:OR and WP:COI. Unless you are able to produce reliable 3rd party references to demonstrate the notability of this theorem, it does not belong on Wikipedia-- Jac 16888 Talk 16:40, 28 September 2014 (UTC)
 * WP:COI and WP:PROMO are not reasons to delete an article, just reasons to apply a template, and WP:OR is not relevant here as the theorem is discussed in a peer-reviewed journal. --Sammy1339 (talk) 23:22, 28 September 2014 (UTC)


 * Weak keep. It has received independent attention as a subject of articles in a peer-reviewed journal:, which is enough for WP:SIGCOV. Granted that's not a widely read journal among research mathematicians, but it's a respectable source and perhaps the best one out there for the obscure topic of classical plane geometry. There is a tendency to apply a much higher notability standard to scientific topics than all the other stuff that goes into Wikipedia, which I don't understand. There was even this failed proposal: Notability (science). It failed for good reason. --Sammy1339 (talk) 23:17, 28 September 2014 (UTC)


 * Comment. Alright there are some obvious major issues with this. One is the naming. No independent source actually refers to any of these statements as "Dao's Theorem," so the title has to be changed. You can't name a theorem after yourself. Second, not all of these statements are notable, so the article reads like a summary of the work of Dao, a non-notable amateur mathematician. However I think some of the work is interesting and possibly significant.  Perhaps you should userfy the whole article and incorporate the generalization of Goormaghtigh's Theorem as a separate section in a new article about that theorem. Also please note that notability is based on citations or mentions in independent texts. See WP:GNG. Some things may not be notable simply because they are too new to have received attention. It's not a criticism of the merit of the work. --Sammy1339 (talk) 03:04, 29 September 2014 (UTC)


 * Comment Hi Sammy1339, Please see: Thébault's theorem, Harcourt's theorem, Archimedes' quadruplets, I want write Dao's theorem similarly form of Thebault theorem. Could You help me? Thank to You.--Eightcirclestheorem (talk) 05:22, 29 September 2014 (UTC)


 * Hi Jac 16888 , You wrote: Unless you are able to produce reliable 3rd party references to demonstrate the notability of this theorem.


 * Now we come back to Tran Hoang Son's article see References [7] O.T.Dao, Message Advanced Plane Geometry 1271, April/26th/2014. and we also come back Nikolaos Dergiades's article see References [3] T. O. Dao, Advanced Plane Geometry, message 1531, August 28, 2014. Now we together visit to there:


 * The cite source of Tran Hoang Son's article is: https://groups.yahoo.com/neo/groups/AdvancedPlaneGeometry/conversations/messages/1271


 * The cite source of Nikolaos Dergiades's article is https://groups.yahoo.com/neo/groups/AdvancedPlaneGeometry/conversations/messages/1531


 * Who is post the topics 1271 and 1531? we can see that Dao Thanh Oai posted this topic with his signature is Dao Thanh Oai and by his email is : yeuemtrondoitb85@yahoo.com, therefor Oai.T.Dao in Tran Hoang Son's article and Dao Thanh Oai in Nikolaos Dergiades's article is the same person.


 * Note that: the group Advanced Plane Geometry, is page to discussion of the journal: Forum geometricorum, please click http://forumgeom.fau.edu/FG2014volume14/FG2014index.html.


 * Now we come back Dao's article http://forumgeom.fau.edu/FG2014volume14/FG201410.pdf, please see in References [1] T. O. Dao, Advanced Plane Geometry, message 942, December 7, 2013. Now we visit to there topic 942 https://groups.yahoo.com/neo/groups/AdvancedPlaneGeometry/conversations/topics/942 . Dao Thanh Oai posted this topic with his signature is Dao Thanh Oai and by his email is : yeuemtrondoitb85@yahoo.com. So three persons in three articles refer to one person with name: Dao Thanh Oai.


 * Note that his address at there is Dao Thanh Oai: Cao Mai Doai, Quang Trung, Kien Xuong, Thai Binh, Viet Nam, with another his E-mail address: daothanhoai@hotmail.com. Now we come back to another his paper http://forumgeom.fau.edu/FG2014volume14/FG201418.pdf you see at References Dao Thanh Oai: Cao Mai Doai, Quang Trung, Kien Xuong, Thai Binh, Viet Nam E-mail address: daothanhoai@hotmail.com So Dao Thanh Oai in four articles is one person.


 * Now, we visit again to http://cms.math.ca/crux/v39/n5/ please see problem 3845, you see that Dao Thanh Oai, Kien Xuong, Thai Binh, Viet Nam it is the same address of Dao Thanh Oai in two his papers above. So five persons in five papers with name Dao Thanh Oai refer one person with name Dao Thanh Oai


 * So may I write a page Dao's theorem with similarly form of Thébault's theorem? :::--Eightcirclestheorem (talk) 07:30, 29 September 2014 (UTC)


 * Strong keep. Dao theorem are generalization of some famous theorems, so they are nice and notable theorem.PhamNguyenBang (talk) 14:45, 29 September 2014 (UTC) — PhamNguyenBang (talk • contribs) has made few or no other edits outside this topic.
 * Delete per WP:TOOSOON. There is a little bit of secondary sourcing (the Dergiades paper) but not enough to evaluate the impact of this result nor to pass the requirement of WP:GNG for multiple secondary sources. I am not convinced that the other non-Dao source (the Tran paper, in "Global Journal of Advanced Research on Classical and Modern Geometries") is a reliable source; for instance, this journal is not indexed in MathSciNet. And the pattern of apparent self-promotion and possible sockpuppetry here (and at past AfDs for similar material, e.g. Articles for deletion/Dao six-point circle) is very troubling. —David Eppstein (talk) 19:00, 29 September 2014 (UTC)
 * A bout Articles for deletion/Dao six-point circle please click http://faculty.evansville.edu/ck6/encyclopedia/ETCPart4.html#X5569 and http://www.cut-the-knot.org/m/Geometry/CirclesTangentToMedians.shtml. And I post this because my friend said to me that Kimberling center is cite source for another dictionary, so I posted. Why I posted with name: Dao's six point circle?? Because two web sites above (cut the knot, and Kimberling ETC) wrote this with title Dao's six point circle so I rewrite with the same title, I don't think I write with another title that time. Please note that at https://en.wikipedia.org/wiki/Wikipedia:Articles_for_deletion/Dao_six-point_circle, wrote by Sławomir Biały  as follows:


 * Yes, we publish notable results of amateur mathematicians. This needs to be evidenced by a number of sufficiently high quality secondary sources (a paper or book chapter, for instance).  But we don't just publish any old result (even those by professional mathematicians).  We have guidelines that help to objectively determine whether a result is notable in this sense..


 * So now Tran Hoang Son's paper with title: A synthetic proof of Dao's generalization of Goormaghtigh's theorem and Nikolaos Dergiades's paper with title : Dao's theorem.....On the other hand, because these are nice results in Euclidean plane geometry. Why I said that these results are nice in Euclidean plane geometry because these results are generalization of some famous theorem. so I want to share these result to everybody, so I wrote this pages with the same title Dao's theorem(this are same with title of two papers above). I also don't think it is self-promotion. --Eightcirclestheorem (talk) 07:30, 30 September 2014 (UTC)


 * On the other hand, I think Dao's theorem are theorems in Euclidean plane geometry, so they should be publish in a journal of Euclidean plane geometry, on the other we also see that has very few journal of Euclidean plane geometry have indexed in MathSciNet. So I think the cite source of Dao's theorem are: Three sources in the Forum Geometricorum journal of Department of Mathermatucal Sciences Florida Atlantic University http://forumgeom.fau.edu/, one sources in the Crux mathmaticorum journal-Canadian Mathematical Society http://cms.math.ca/crux/v39/n5/, and one paper in the http://gjarcmg.geometry-math-journal.ro/, I think that in Euclidean plane geometry, these journal are reliable source. On the other hand note that Articles for deletion/Dao six-point circle also will appear in a journal in 10/2014.--Eightcirclestheorem (talk) 00:05, 30 September 2014 (UTC).


 * Note that: Now the Dao Thanh Oai's paper appear online. He show that Dao six point circle and the famous van Lamoen circle are special case of theorem 3.1 in his paper, please click. http://ijgeometry.com/wp-content/uploads/2014/10/9.pdf. --Eightcirclestheorem (talk) 01:55, 3 October 2014 (UTC)


 * Comment You mean: Dao's theorem on the arbelos with thre cite source http://forumgeom.fau.edu/FG2014volume14/FG201418.pdf; http://www.cut-the-knot.org/m/Geometry/DaoTwins2.shtml ; http://www.cut-the-knot.org/m/Geometry/DaosTwins.shtml; can not is small item in wiki. But there are other articles just as Archimedes' quadruplets as this one.--Eightcirclestheorem (talk) 01:59, 3 October 2014 (UTC)


 * Comment You said: There is a little bit of secondary sourcing (the Dergiades paper) but not enough to evaluate the impact of this result nor to pass the requirement of WP:GNG for multiple secondary sources, but there are other articles just as Harcourt's theorem as this one. The Harcourt's theorem paper also wrote by Nikolaos Dergiades, also publish in FG(Forum Geometrycorum). And today Telv Cohl publish this Dao's theorem http://forumgeom.fau.edu/FG2014volume14/FG201429.pdf Dao's theorem has enough multiple secondary sources. On the other hand this theorem also posted by Dao Thanh Oai in Cut the knot since 24 December 2013. So now, I think this theorem is enough long time and enough multiple secondary sources. You can see also: http://www.cut-the-knot.org/m/Geometry/AnotherSevenCircles.shtml --Eightcirclestheorem (talk) 15:09, 30 September 2014 (UTC)


 * I think, I will write three articles with titles: Goormaghtigh theorem, Vecten points, Kosnita theorem to show detail these theorems relation with Dao's theorem. Please note that new version of Dao's problem on eight circles will appear in AMM Journal in next year.--Eightcirclestheorem (talk) 04:26, 4 October 2014 (UTC)


 * Comment for the messege:

Please checked detail again, and remove the messege "Orphan" above because:


 * Dao's problem on eight circles, the article for this section: Dao Thanh, Oai (2014). "Issue 5, Problem 3845". In Shawn, Godin. Crux Mathematicorum 39. ISSN 1496-4309.


 * Dao's generalization of Goormaghtigh's theorem, the article for this section: Tran Hoang, Son (2014). "A synthetic proof of Dao's generalization of Goormaghtigh's theorem". In Pișcoran, Laurian-Ioan. Global Journal of Advanced Research on Classical and Modern Geometries 3. pp. 125–129. ISSN 2284-5569.


 * Dao’s theorem on six circumcenters associated with a cyclic hexagon, the article for this section: Dergiades, Nikolaos (2014). "Dao’s Theorem on Six Circumcenters associated with a Cyclic Hexagon". In Yiu, Paul. Forum Geometricorum 14. pp. 243–246. ISSN 1534-1178. and  Cohl, Telv (2014). "A purely synthetic proof of Dao's theorem on six circumcenters associated with a cyclic hexagon". In Yiu, Paul. Forum Geometricorum 14. pp. 261–264. ISSN 1534-1178.


 * Dao's theorem on a rectangular hyperbola, the this article for this section: Dao Thanh, Oai (2014). "A Simple Proof of Gibert’s Generalization of the Lester Circle Theorem". In Yiu, Paul. Forum Geometricorum 14. pp. 201–202. ISSN 1534-1178.


 * Dao's theorem on the arbelos, the article for this section:  Dao Thanh, Oai (2014). "Two pairs of Archimedean circles in the arbelos". In Yiu, Paul. Forum Geometricorum 14. pp. 201–202. ISSN 1534-1178.


 * Dao six point circle, the article for this section: Dao Thanh, Oai (2014). "A synthetic proof of A.Myakishev's generalization of van Lamoen circle and an apllication". In Barbu, Catalin. International Journal of Geometry 3. pp. 74–80.


 * Dao's theorem on concurrence of three Euler line, the article for this section: Cohl, Telv (2014). "Dao's theorem on concurrence of three Euler lines". In Barbu, Catalin. International Journal of Geometry 3. pp. 70–73. ISSN 2247-9880.--Eightcirclestheorem (talk) 15:22, 4 October 2014 (UTC)


 * Delete - Not only does the article look somehow promotional, but a search for significant reliable sources comes up empty. As mentioned above, it appears to have been mentioned in at least one journal, but the reliability of said journal is questionable. No prejudice against a neutrally-written recreation should this become notable in the future. Narutolovehinata5 tccsdnew 03:04, 5 October 2014 (UTC)


 * Keep I write this page as following form of Thébault's theorem based on some articles publish in some journal. I write this page with neutrality, no promotional Dao Thanh Oai(I can not write this page with another name because title of some articles at here is Dao's theorem.....) Please noting that Dao's theorem is theorem on Euclidean geometry, and these Journal is classical of Euclidean geometry. If these theorem is no notable theorem we should delete pages but Dao's theorem is nice and notable theorem(because it is generalization of some famous theorem), so I think we should keep and improvement of this pages. Eightcirclestheorem (talk) 05:15, 5 October 2014 (UTC) User already voted.  Sławomir Biały  (talk) 12:20, 15 October 2014 (UTC) . I voted only time at here --Eightcirclestheorem (talk) 16:03, 15 October 2014 (UTC)


 * Keep for some time Before discarding it, we should give other editors interested in the topic a chance to salvage it. I will try to do so as time allows.  It is not vandalism, not incorrect, and has indepenent references (so it is no longer "original research").  The only reason to delete it would be "not sufficiently notable", which, at the very least, is a subjective evaluation.  Perhaps the article should be renamed, but deleting this article will not only remove useful content from Wikipedia, but also drive away another potential editor who could contribute contents to it -- a precious resource that Wikipedia is running out of. --Jorge Stolfi (talk) 05:37, 5 October 2014 (UTC)
 * PS. By the way, this theorem will still be true 1000 years from now, when no one will know, or care to know, who was Justin Bieber. Just to put the notion of "notable" in perspective. 8-) --Jorge Stolfi (talk) 05:37, 5 October 2014 (UTC)


 * Comment Dear everybody. why I said that these theorems are notable theorem? Because example, in the configuration of "Dao’s theorem on six circumcenters associated with a Cyclic Hexagon", please see the picture on the right hand.




 * Pascal's theorem, on this configuration, Pascal theorem states that: Denote the line $$A_2A_5$$ meets the line $$A_3A_6$$ at $$P$$ then $$P,B_2,B_5$$ are collinear $$ \Longleftrightarrow $$(equivalence) $$A_2A_5,A_3A_6$$ and $$B_2B_5$$ are concurrent;


 * Dao's theorem, also on this configuration, Dao's theorem states that: $$C_1C_4,C_2C_5$$ and $$C_3C_6$$ are concurrent.--Eightcirclestheorem (talk) 06:20, 5 October 2014 (UTC)


 * Notice Editor Eightcirclestheorem has canvassed a number of editors about this discussion and the article's potential for deletion. So far as I can tell, Eightcirclestheorem selected editors who had commented on related mathematical articles before, not necessarily at Afd. The list includes myself, Lemontea, Gene Ward Smith, Reverendgraham, Kmhkmh, Rick Norwood, Pbroks13, Duoduoduo, Tokek, Krishnachandranvn, WillowW, Jorge Stolfi, Markmichaelh, and Magioladitis. It appears that this is not vote-stacking, but is based on "Editors who have participated in previous discussions on the same topic (or closely related topics)" or "Editors known for expertise in the field."  I note that editors with expertise who have not edited in some months were among those selected. I have chosen not to comment on the merits of this Afd. As a new user Eightcirclestheorem may not know that it is appropriate to provide notice of such canvassing. It is good practice to leave a note at the discussion itself about notifications which have been made, particularly if made to individual users. Wikipedia:Canvassing.  --Bejnar (talk) 15:51, 5 October 2014 (UTC)


 * Yes, Thank to dear Bejnar. Because I want a people have knowledgeable classical geometry who give comment "delete" of "keep"; my messege as following:


 * Dear Mister X,


 * I known You because You are creator of pages Y, so You are knowledgeable classical geometry, please read pages Dao's theorem and comment anything You think. Delete or keep pages Dao's theorem


 * Thank to You very much.


 * Best regards
 * Sincerely


 * My canvassing is neutralist: Because I comment: Read and comment anything you think, delete or keep pages Dao's theorem --Eightcirclestheorem (talk) 16:53, 5 October 2014 (UTC)


 * Weak keep. It looks, from the above, like the article is self-promotion.  But the theorems are so nice (if true) that I hate to see the article just go away forever.  Eightcirclestheorem: do you have any referee reports or other confirmation of the results? Rick Norwood (talk) 17:21, 5 October 2014 (UTC)


 * Thank to dear Rick Norwood. I can not sent direct some review at here, if You want I can sent to You by email of some review. But You can  check direct online of Dao's theorem  to show it true or not true:


 * 1-Eight circles problem, true or not true please click(seclect and move object):                          http://www.geogebratube.org/student/m168042


 * Nice or not nice? please see:


 * See also Brianchon theorem
 * See also Pascal theorem
 * See also Seven circles theorem


 * 2- Another seven circle theorem, true or not true please click(seclect and move object):               http://www.geogebratube.org/student/m168046


 * Nice or not nice? please see:


 * See also Brianchon theorem
 * See also Pascal theorem
 * See also Seven circles theorem
 * See also Kosnita theorem


 * 3- Dao's six point circle, true or not true (seclect and move object):                     https://www.geogebratube.org/student/m129285
 * Nice or not nice? please see:
 * See also https://nl.wikipedia.org/wiki/Cirkel_van_Van_Lamoen


 * 4- A generalization Goormaghtigh theorem, true or not true please click (seclect and move object): http://geogebratube.org/student/m168465


 * (Note that, Tran Hoang Son's article only give solution of special case 2 this here, and I only wrote this section based on Tran Hoang Son's article)


 * 5-Dao's theorem on rectangular hyperbola true or not true please click (seclect and move object)                    http://www.geogebratube.org/student/m168475


 * Nice or not nice? please see:


 * See also Vecten points
 * See also Lester's theorem. Note that Let ABC be a triangle, two Fermat point, two Vecten points and the orthocenter, and the centroid lie on Kiepert hyperbola. Two Vecten points and Nine point center are colliear. On the other hand the line through two Fermat points meet the Euler line at midpoint of the centroid and the orthocenter (This intersection point is X(381) in Kimberling center), so tangent of Kiepert hyperbola at two Fermat point parallel to Euler line. Therefor Lester theorem is special case of this theorem.


 * 6-Dao's theorem on the arbelos


 * Nice or not nice? please see


 * See also Archimedes' quadruplets


 * As You known, my english is not good, so I had not read WP:PROMO and WP:TOOSOON and...... so I did not know that wiki don't want I wrote for my theorem. When I received your comment, I understand that I should not write directly for my theorem at here. But You can easily to see that I write with neutralist style.--Eightcirclestheorem (talk) 04:10, 6 October 2014 (UTC)

Proposal OK, here is my proposal to fix the article: Sound OK? --Jorge Stolfi (talk) 05:02, 6 October 2014 (UTC)
 * Move two or three of the sections, those that have complete description and references, to separate articles with more specifi names, e.g., Dao's eight circles theorem Dao's six circumcenter theorem.
 * Move the remaining sections that are generalization of other better-known theorems to the articles on these theorems. See for example Droz-Farny line theorem.
 * Turn this article into a disamb page, like Sylvester's theorem.
 * Correction Dao's eight circles problem was posed by Dao, but proved by Dergiades, so the proper name is uncertain. --Jorge Stolfi (talk) 05:14, 6 October 2014 (UTC)
 * Dear Eightcirclestheorem, it is OK to fix other people's typos and formatting, but not to change what they wrote. If you have corrections (like Dergiades --> Luis González), write them separately and sign them with your name. And try to be more succint in your comments... --Jorge Stolfi (talk) 12:41, 7 October 2014 (UTC)


 * Special case of Dao's theorem on three Euler lines is X(4240) = DAO TWELVE EULER LINES POINT in Kimberling center, true or not true please click (seclect and move object). http://www.geogebratube.org/student/m168648 , Please see also: http://faculty.evansville.edu/ck6/encyclopedia/ETCPart3.html#X4240 --Eightcirclestheorem (talk) 07:37, 6 October 2014 (UTC)


 * Relisted to generate a more thorough discussion so a clearer consensus may be reached.


 * Please add new comments below this notice. Thanks, NorthAmerica1000 11:36, 6 October 2014 (UTC)



Dear Dr. David Eppstein,

I already read article David Eppstein. So I know that You are very an expert geometer. You can check direct these theorem from:

http://www.geogebratube.org/student/m168042

http://www.geogebratube.org/student/m168046

https://www.geogebratube.org/student/m129285

http://geogebratube.org/student/m168465

http://www.geogebratube.org/student/m168475

http://www.geogebratube.org/student/m168648

And note that these theorems are theorem of Euclidean plane geometry

Please checked Dao's theorem again and give your comment. These theorem are nice or not nice?

Best regards Sincerely --Eightcirclestheorem (talk) 11:31, 7 October 2014 (UTC)

Dear Mister Sammy1339,

You wrote: "You can't name a theorem after yourself."

Yes, I did not name theorems after my name, I name these theorems after title of some papers and title of some points in Kimberling center, and pages of Cut the knot and I want wrote this page similarly form of Thébault's theorem or Sylvester's theorem. I wrote this page with neutralist style.

Best regards Sincerely --Eightcirclestheorem (talk) 11:32, 7 October 2014 (UTC)


 * General question The topic of the article is advanced plane Euclidean geometry, which appears to have a very active community of devoted researchers. See for example this forum.  In that community, is it customary to name a theorem after the person who first stated it, or the person who first provided a proof for it? --Jorge Stolfi (talk) 13:19, 7 October 2014 (UTC)


 * Comment: A theorem publish in a journal or a book only is legal grounds to everybody authenticate the theorem(copyrights of the theorem). But a theorem is nice or isn't nice that it is itself(nice or not). Why do we know a theorem is nice or isn't nice? We should compare this theorem with another famous theorem to known that. Today, a theorem of classic Euclidean geometry usually less published in high quality journal(very reliable source) or some reasons another. So, normally these theorem at here should be publish in classic Euclidean geometry journal. And now, these true nice theorem be published on some journal and Kimberling center and some famous web site (of Euclidean geometry). But  Narutolovehinata5 said that " *Delete ....As mentioned above, it appears to have been mentioned in at least one journal, but the reliability of said journal is questionable " is not logical. On the other hand You can check direct from link above to show that these theorem true or fail. If opinion of Narutolovehinata5 is logical, we must delete many another theorem in wikipedia. With me, a theorem of plane geometry is nice <=> notable theorm.


 * If everybody have no suggestions, we should keep these theorem by some reasons as follows:


 * 1-Reference from some article which appear online in some journals and Kimberling center (or) and another some web sites.


 * 2-These are true result(because You can check directly from link above) and these are nice(notable) theorem (Because easily to see that these are generalization of a famous theorems)


 * 3-The site sources wrote with title "Dao's theorem...." and refer one person with name Dao Thanh Oai, or by Dao Thanh Oai wrote the theorem in his articles.

--Eightcirclestheorem (talk) 08:19, 13 October 2014 (UTC)


 * Keep Considering that we proudly host promotional articles about 'music' bands that were formed yesterday, we can jolly well keep an article like this. Jayakumar RG (talk) 15:10, 10 October 2014 (UTC)


 * Comment A speedy deletion has been requested for Dao's six point circle, that I had recently created out of a section of Dao's theorem in an attempt to turn the latter into a disamb page, as proposed above. It seems that a previous article on that topic had been created by Mr. Dao, and was then deleted.  I was not aware of that previous incarnation (perhaps the name was slightly different?) Anyway, I believe the situation of "Dao's six point circle" is a bit different now; for one thing, as Mr. Dao pointed out, there are a few more references in sufficiently formal journals, and other people in the Euclidean plane geometry commmunity seem to have accepted the name.  Mr. Dao can be forgiven for not following The Rules.  One cannot expect a new editor, who only wishes to contribute narrowly on a topic of his interest, to read that ocean-size morass that is the 'Wikipedia:*' namespace, and note down all the rules that he is supposed to follow. Anyway, Mr. Dao is now aware that Wikipedia discourages editors from writing articles about their own work, and that one should not create an article about every single theorem that anyone has published. I wish that there was a better way to warn him of these principles than dragging him to this Holy Inquisition Tribunal that is the AFD. (In spite of my efforts to reach a Zen-like detachment, the two of three articles of mine that got killed here -- sometimes before I had time to intervene -- seem to weigh more in my memory than the hundreds that got accepted... 8-/ ) By the way, what is really the rationale for the "non-notability" deletion in this case (beyond "it is the Rule")? The Dao's six point circle article seems to be correct (and has the correct name), non-trivial, timeless, sourced, and "encyclopedic" enough in style (I hope). It will be useful to readers who are looking for it, will not inconvenience readers who are not looking for it, and consumes very few resources at the servers. Will Wikipedia really be better without it? All the best, --Jorge Stolfi (talk) 19:42, 10 October 2014 (UTC)

[ Keep: ] It would be really sad if the article get deleted. The theorem is novel, the synthetic proof is not obvious at all and it is very nice. The theorem have been cited twice, what else is needed? Some results in wikipedia have receive less attention and hey! why are they on wikipedia? [ unsigned comment by User:Emmanuel García 23:08, 2014 October 10. Moved from Talk page to here by Jorge Stolfi (talk) 23:40, 10 October 2014 (UTC) ]


 * Dear Dr Jorge Stolfi and Dr David Eppstein and all Friends.


 * I am thank to everybody, special many thank to Dr Jorge Stolfi. But from standard (in my idea) of nice or not nice or notable and non-notable. And I think wiki only write notable theorem, so I think we should keep what are really nice in pages Dao's theorem (Shouldn't keep all Thanh Oai's result at Dao's theorem, I mean don't write all Dao Thanh Oai's results at Dao's theorem). I think we should write this pages as follows:


 * In Euclidean plane geometry, Dao's theorem may refer to any of several theorems or constructs associated with mathematician Đào Thanh Oai:


 * Dao's eight circles problem, a generalization of Brianchon's theorem.
 * Dao's six circumcenter theorem, a generalization of Kosnita's theorem.
 * Dao's generalization to Goormaghthigh's generalization of the Droz-Farny line theorem


 * What do you think about my idea above? --Eightcirclestheorem (talk) 21:43, 13 October 2014 (UTC)


 * Dear Dr. David Eppstein, please let me know as soon as possible what do you think with last form of Dao's theorem? keep or delete, if you think should delete I agree to delete, if you think should keep I also agree to keep. Thank to you very much.


 * Dear Dr Jorge Stolfi, if this article be delete, I am really sorry to You because I don't know You, but you help me very much. I am very thank to You dear Dr. Jorge Stolfi. --Eightcirclestheorem (talk) 08:06, 14 October 2014 (UTC)


 * delete. A bit late to this but whether it's the earlier version of the page before forking or the current dab-like page this doesn't belong, as a blatant attempt at self-promotion, using WP to promote your research long before its picked up by reliable sources.-- JohnBlackburne wordsdeeds 00:01, 15 October 2014 (UTC)


 * Values of JohnBlackburne's comment above? I think he no read all comment above at here. I think he don't has knowledgeable of classical geometry, he did not check these theorem, did not read the articles, so may he let "delete" or "keep" is not values. I think he should remember Forum geometricorum is a journal which has indexed in Mathscinet, and Crux Mathematicorum is the best solution of solving Journal in the world(the journal is member of Canadian Mathematical Society). On the other hand now, never publish a theorem of classical geometry in Acta Numerica, Annals of Mathematics or a high another journal of mathematic...... And these theorem are generalization of famous theorem of classical geometry with reasons above why delete? on the other hand WP:PROMO are not reasons to delete an article. And I didn't know wiki don't want I post so I post, If I know wiki didn't want I post so I never post, and never said to you that I am Dao Thanh Oai. I research geometry to relax because I am electrical system engineer, I have no received money from geometry(In three years research). Original of my idea post at here because I want to share. Now these result publish in some best journal of classical geometry, and these theorems are generalization of famous theorem of classical geometry why delete? And I didn't name these theorem after my name. I name these theorem from title of these paper ? why delete. I waiting Dr David Eppstein comment again, Dr David Eppstein is decided.--Eightcirclestheorem (talk) 02:36, 15 October 2014 (UTC)
 * FWIW I have a degree in mathematics, have taught it for many years, and have edited and contributed to many mathematics articles here, including largely writing a few. So I think I am qualified. But WP doesn't work like that anyway. We don't pull rank on each other over who has the most knowledge. At best doing so shows you are unwilling or unable to argue on the actual policies, if you're resorting to questioning other editors abilities, so have already lost the argument. At worst it's a form of personal attack, and so is completely unacceptable. As that page says, "comment on the content, not on the contributor". Continuing to comment on other editors can lead to sanctions.-- JohnBlackburne wordsdeeds 02:49, 15 October 2014 (UTC)
 * I believe that your objections -- "self promotion", reliable sources, etc. -- are all answered above. AFAIK this theorem was never proposed for deletion before. (Are you confusing it with Dao's six point circle perhaps?) I did the fork from Dao's theorem, as I had proposed to do above (with no one objecting), and worked on its style, because I cannot see any rational reason to throw away such an article.  I honestly cannot see how that would make Wikipedia better, quite the contrary.  Check five circles theorem for example. (And please try to see beyond issues of "protocol" and personal communication skills.)  --Jorge Stolfi (talk) 03:21, 15 October 2014 (UTC)
 * PS. The discussion is becoming confused because the Dao's six circumcenter theorem has also been proposed for deletion now by and the discussion is being redirected here too. They are different in elegance, references etc. --Jorge Stolfi (talk) 03:28, 15 October 2014 (UTC)


 * Comment: Dear JohnBlackburne. I given a question 10 days ago, but no received answer from Dr David Eppstein, he is expert geometer. Please answer all question above? why delete? these theorem is classical geometry publish in a journal of classical geometry, this is nice result because these are generalization of famous theorem of geometry, and I research geometry to relax because I am electrical system engineer, I have no received money from geometry(In three years research). Original of my idea, I post at here because I want to share. Because I am not enough english to read policy of wiki so I posted. Because your comment is not justifiable (not logical) so I think exactly you don't read all comment above, don't compare these theorem with another theorem, don't check detail. If I said fail, please comment detail: Why do you want delete these theorem ?


 * First reason is:....


 * Secon reason is:....


 * Third reason is:....


 * If reason of You are true, I agree delete.--Eightcirclestheorem (talk) 11:55, 15 October 2014 (UTC)


 * Comment: I am sure: JohnBlackburne proposed delete Dao's six circumcenter theorem because he want personal revenge. He didn't need proposed delete Dao's six circumcenter theorem, because If Dao's theorem be delete then Dao's six circumcenter theorem be delete. --Eightcirclestheorem (talk) 11:55, 15 October 2014 (UTC)


 * Comment. It has become no longer clear what the topic of discussion here is.  Since the article Dao's theorem was first listed here, content has been confusingly forked off to several articles: Dao's eight circles problem, Dao's six point circle, Dao's six circumcenter theorem.  Apart from a very vocal group of one or two editors, there seems to be consensus that all of these articles lack adequate sourcing.  The sourcing for the article Dao's eight circles problem is particularly poor, with only a single primary source listed as a reference.  The title Dao's six point circle is essentially a recreation of content already deleted following an earlier discussion, and is sourced largely to things like forum posts.  The sourcing of Dao's six circumcenter theorem (currently under PROD) looks a bit better, with two secondary sources (albeit published in the questionable journal  Forum Geometricorum).   Sławomir Biały  (talk) 12:10, 15 October 2014 (UTC)


 * Comment. Dear Sławomir Biały, your comment very exactly, I am thank to You.


 * - First: "Dao's eight circles problem is particularly poor" is exactly, but these problem publish in a Crux(very Reliable sourse with classical geometry). And we can easily see that this result is generalization of famous theorem: Brianchon's theorem, and nice similarly Seven circles theorem, Five circles theorem, Six circles theorem so maybe this problem is nice, so do you think we should delete or keep?


 * - Second: Dao's six circumcenter theorem publsih in FG(A journal has index Mathscinet) with two proofs independent, and publish on cut the knot a year ago. This is generalization of Kosnita theorem. And this theorem similarly Seven circles theorem, Five circles theorem, Six circles theorem, so do you think we should delete or keep?


 * - Third Dao's generalization of Goormmaghtigh's theorem, a paper publish in a journal, this result only is a section of Droz-Farny line theorem.--Eightcirclestheorem, so do you think we should delete or keep?--Eightcirclestheorem (talk) 14:09, 15 October 2014 (UTC)


 * Please stop voting more than once. I did not comment on the reliability of the Crux source, but I merely attested that it is not a valid secondary source.  See WP:PSTS.  No one is saying that these theorems are not "nice", but that is not a valid reason to have an encyclopedia article on a topic.  Sławomir Biały  (talk) 14:03, 15 October 2014 (UTC)


 * Comment, yes Ok(I adited about voting), thank to You. I also sent the proof of Dao's eight circles problem to Crux, and waiting the journal publish this proof, may you can check direct at http://www.geogebratube.org/student/m168042 ? On the other hand, another high version of Dao's eight circles problem also publish in AMM journal in next year. --Eightcirclestheorem (talk) 03:47, 16 October 2014 (UTC)


 * Comment: I want said that I don't know why keep: Equal incircles theorem, Harcourt's theorem and Archimedes' quadruplets but some member want delete Dao's six circumcenter theorem ?--Eightcirclestheorem (talk) 13:59, 16 October 2014 (UTC)
 * See WP:OTHERSTUFF. What other articles exist is irrelevant to this discussion.-- JohnBlackburne wordsdeeds 20:46, 16 October 2014 (UTC)


 * Redirect to Dao's eight circles problem. This article is now a dab page, but Dao's eight circles problem seems to be the only article that will be kept, so a dab page is not needed. Even if Dao's six circumcenter theorem is also kept, a redirect and hatnote are still appropriate. However, none of these theorems satisfy WP:N, so I would also be !voting "delete" on Dao's six circumcenter theorem and Dao's eight circles problem if they came up for AfD. -- 120.23.70.34 (talk) 08:34, 18 October 2014 (UTC)


 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.