Talk:Algebra extension

Requested move 28 May 2016

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. No further edits should be made to this section.

The result of the move request was: Moved as unopposed, with a comment from creator about original title intentions. (non-admin closure) — Andy W. (talk · ctb) 05:53, 20 June 2016 (UTC)

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Algebra extension → Ring extension – The article appears to define "ring extension" first in the lead. The page Ring extension already existed as a separate article that was merged into Subring#Ring extensions by David Eppstein. GeoffreyT2000 (talk) 23:22, 28 May 2016 (UTC) -- Relisting. Anarchyte (work | talk) 02:20, 5 June 2016 (UTC) --Relisting. — Music1201 ^talk 01:25, 12 June 2016 (UTC)

• Comment from the creator: Both titles are reasonable. The reason I chose "algebra extension" instead of "ring extension" is because the latter seems more ambiguous: it can also mean a relationship between two rings (one subring of the other). The "extension" here in this article comes from group extension. "Algebra extension" seems not to suffer from this issue. But again both names would work so I'm not casting a vote. -- Taku (talk) 00:49, 29 May 2016 (UTC)

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The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Multiple issues

Despite the recent removal, the article has still multiple issues. Here are some of them in a random order.

• Probable WP:OR: the first definition is intended for a non commutative ring R and an abelian group I. There is no evidence that this definition has been given in a notable published article. When R is commutative and I is an R-module, it is not clear that the concept has been considered for other extensions than those where the product in E of two elements of I is always zero.
• Lack of context: It must be clear in the article where the topic is used. AFAIK, only the example 2 is notable. In any case every significant incoming link are targeted to the example 2.
• Misnomer: It is clear that when specalists of commutative algebra encounter the phrase "ring extension”, they think first of the meaning that is linked to in the hatnote. So the primary topic for this phrase is that which is linked to the target of the hatnote. It follows that the aricle title must redirect to the target of the hatnote, and that this article must be moved to another title.
• Technical accuracy: the first example is full of errors. I am unable to decide whether it is intended to be a special case of § Example 2 or not.
• Essentially an orphan, as except for a redirect to § Example 2, incoming links are either erroneous or from a “See also” section (a dab hatnote and a unlinked glossary entry are kinds of “see also”).

All these issues suggest to nominate this article to AfD. However the example 2 is worth be kept and expanded. IMO, Algebra of dual numbers is not a good title, and I suggest Idealization of a module.

So, I’ll redirect again the title to Subring#Ring extensions, expand Example 2 under the suggested title, and redirect there Algebra of dual numbers.

To editor TakuyaMurata:: some opinion? D.Lazard (talk) 11:43, 2 March 2023 (UTC)

I think the main issue is that ring extension can have two meanings: one that generalizes a field extension and the other that generalizes a group extension. I don’t know which one is more common. Note the article ring extension used to be called algebra extension (see above), in part because of this issue. An algebra extension is a valid topic in abstract algebra so we still need an article on it (in fact the article contains refs); I don’t think having an article devoted the special case of principle of idealization is a good idea. By the way, "idealization of a module" is not a standard terminology so we can’t use that term. —— Taku (talk) 14:56, 2 March 2023 (UTC)

(By the way, I didn’t add Example 1 and so I don’t know anything about it). I suggest we move the article to "algebra extension", which seems to be the easiest solution. —- Taku (talk) 15:04, 2 March 2023 (UTC)

Requested move 2 March 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.

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Idealization of a module → Algebra extension – The reason is given in the preceding thread.Taku (talk) 15:09, 2 March 2023 (UTC)

Note: pages with content, such as Algebra extension, are ineligible to be new titles in move requests unless they, too, are dispositioned. "Algebra extension → ?" has been added to this request to satisfy that requirement. P.I. Ellsworth , ed. ^{put'er there} 00:03, 3 March 2023 (UTC)

Sorry, I meant to suggest the current very short placeholder article algebra extension be replaced by Idealization of a module. Please see the discussion in the previous thread. —- Taku (talk) 07:44, 3 March 2023 (UTC)

• Procedural comment. I deleted Algebra extension as a recently-created article whose author now wants to delete it, after history-merging the history needed for attribution of the previous merge – to Idealization of a module. So if this RM moves back to that title, it won't move over the top of that history. – wbm1058 (talk) 19:45, 3 March 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.

What's the diff?

To editors Taku, D.Lazard and GeoffreyT2000: now, can anyone tell me what the difference is between algebra extension and algebraic extension? P.I. Ellsworth , ed. ^{put'er there} 05:57, 12 March 2023 (UTC)

The two concepts are completely unrelated. I know it’s confusing but the adjective “algebraic” and the noun “algebra” have unrelated meanings. A similar situation happens for representation: algebra representation and algebraic representation are unrelated. —— Taku (talk) 07:04, 13 March 2023 (UTC)

hmm, I would think that "algebra" and "algebraic" are intimately related terms even if they are different parts of speech. However, I will cede that I am not a mathematician (just a lover of math), and that it's true that when a noun like "algebra" is combined with another noun like "representation" or "extension" to result in a noun phrase, a new and separate meaning may evolve. Thank you very much, editor Taku, for your responsive explanation! P.I. Ellsworth , ed. ^{put'er there} 19:34, 13 March 2023 (UTC)

"Trivial extension" listed at Redirects for discussion

The redirect Trivial extension has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2023 December 24 § Trivial extension until a consensus is reached. Jay 💬 11:31, 24 December 2023 (UTC)