Tag management 2021

New year, new tag management thread.

Rules of the game are basically the same:

• Post your suggestion as an answer here if you see
• A particularly bad tag (a rule of thumb: “if I can't imagine a person classifying a tag as either interesting or ignored, I'm getting rid of it”),
• A tag that should be a synonym of an existing one,
• A tag that used for two or more completely unrelated things,
• A need to create a new tag.
• Upvote/downvote/comment as your agree/disagree with suggestions, so please post different suggestions in separate answers.
• Wait a couple of days before implementing a suggestion.
• After the problem described in an answer is resolved, please edit it to say so.
• If your tag suggestion exists in a separate question, please provide a link to the question in your suggestion.

Also, note that one may use [tag:calculus] for , i.e. tags on the main site, and [meta-tag:discussion] for , i.e. for tags on the meta site.

Note that, in some cases, it might be better to have a separate question. Typically this happens when a longer discussion is needed and several possible answers are expected, since answers to a question provide more space for a more detailed discussion than comments under an answer in this thread.

Previous tag management threads:

Resolved: The renaming and synonymizing has been done.

Proposal:

1. Rename the to .
2. Create the tag synonym $$\to$$ .
3. Create the tag synonym $$\to$$ .
4. Create the tag synonym $$\to$$ .

This is related to, but distinct from, J. W. Tanner's proposal, in that it does not create any new tags. The idea has been discussed in the tagging chatroom.

Unless there are any objections, I will implement this proposal in a week.

• I see that you've linked to chat - here is a link which shows the conversation that spans two days. (Although in the first day there are mainly examples of questions about dot product and your messages about updating the tag-info.) And, of course, if the discussion in chat continuous, we can add more to the same bookmark. – Martin Sleziak Jan 7 at 9:36

Proposal: Add the tag

We have around 3k questions associated with stars and bars, meaning that manual editing of these questions to include the tag is out of the question, but nearly every two days, someone asks a duplicate stars and bars problem, so perhaps having a tag for the future may not be a bad thing...

To ensure singular-versus-plural consistency between "mother" tags" and their "children",

Moreover, given , , , I propose that .

At the moment, tag is a synonym for tag . Hence, I propose that

Say, on a question on the number of real roots of a given cubic polynomial, I would rather see tag than tag . The roots may be found by solving a cubic equation, but the question is on the polynomial itself, isn't it?

Resolved: Both tags renamed.

Proposal: Rename to , to

Nothing too crazy here, just some quick grammar fixes.

Proposal: create qr-decomposition

There are already lu-decomposition, cholesky-decomposition, schur-decomposition and other related tags on eigenvalues or the SVD. But not qr-decomposition, while there seem to be many questions on this.

Alternately, as suggested by Cameron Williams in this (now deleted) question, we might merge all those tags with the tag matrix-decomposition, which already exists. Not my preferred choice, but it's debatable.

• There are over 2K questions with the tag matrix-decomposition. In my opinion, the whole point of having tags of the form xyz-decomposition is to allow users to find the needles in the haystack more easily and more quickly. The cost of having a few extra tags should be negligible when compared to the cost of having members of Math SE wasting time needlessly — say, trying to find duplicates, failing to do so and answering questions that have already been answered dozens of times. – Rodrigo de Azevedo Mar 9 at 1:35
• @RodrigodeAzevedo Agreed. As I said, not my preferred choice, but since someone suggested this in a question I deleted, I felt I had to mention this. – Jean-Claude Arbaut Mar 9 at 8:08

$$\textbf{Resolution}:\;$$ The tag dot-product was created by Xander Henderson;

see that answer for details.

$$\textbf{Proposal}:\;$$ Create the tag dot-product.

There is a tag for cross-product, but not one for dot-product.

There is a tag for inner-product-space, but that is more abstract than the usual dot product for $$\mathbb R^n$$.

• Seems like a synonym would be the ideal solution here, redirecting dot-product to inner-product-space But on the other hand this may confuse users who would be the target audience of dot-product – Alexander Gruber Jan 5 at 1:29
• Are there really enough (unique) good questions about the dot product to justify a tag for it? – Alexander Gruber Jan 5 at 1:30
• @AlexanderGruber I have added a few random examples in the tagging chatroom. Maybe somebody is able to find more of them - and looking at some of those question might help in deciding whether a separate tag for dot product would be suitable. – Martin Sleziak Jan 5 at 6:42
• @AlexanderGruber I agree that a dot-product -> inner-product-space synonym would be ideal. I have edited the inner product space tag wiki in anticipation of such a move (i.e. I have highlighted the dot product a bit more). The goal of the edits was to prevent confusion on the part of "dot product" users. – Xander Henderson Jan 5 at 13:21
• @FearfulSymmetry: I edited accordingly – J. W. Tanner Jan 12 at 18:26
• @MartinSleziak: thanks for the good examples – J. W. Tanner Jan 12 at 18:27

Proposal: Synonimze the meta tag with .

The main tag is synonimized with : this was raised in What is the usefulness of having "proof-verification" and "solution-verification" as different tags?.

I propose that we do the same to the corresponding meta tags. Currently, there are 8 meta questions tagged and 52 meta questions tagged , and 2 questions among these use both tags.

Proposal: Add the meta tag deleted-comments.

This tag is present on meta.SE: https://meta.stackexchange.com/questions/tagged/deleted-comments.

The current meta tag includes

• deleted questions
• posts/comments nominated for deletion.

As a result, to search for meta questions about deleted comments, one has to use the query string "deleted comments" under the tag . Such user experience can be improved by the creation of the meta tag deleted-comments.

Could the relation-algebra tag be reconsidered? It has a description suggesting that would suit relational-algebra. Two separate tags would seem appropriate.

I see this has been discussed years ago: Relation-algebra tag contains also questions about relational algebra

Wikipedia is very clear on the distinction between "relation algebra" and "relational algebra". While there is some overlap (as earlier discussion to above cited question shows) it is a distinction that is useful. References to sources on these two topics do show objectively that overall there is a difference in usage.

The fact that on MathOverflow the same tag "relation-algebra" is given the accepted definition, while here it is described as if it meant "relational-algebra" seems inconsistent and looks like evidence something is not quite right.

How about a tag for L'Hopital's rule?

I have asked a few questions myself involving L Hopital's rule specifically, such as:

'Proof' that $f''(x)=\frac{f'(x)}{x}$

Does L'Hopital's rule imply that $\lim_{x\to a}\frac{f'(x)}{g'(x)} = \lim_{x\to a}\frac{f(x)}{g(x)}$ always?

It would have been useful to have a tag to show that L' hopital's rule was the crux of my questions.

I have also seen many questions that ask about how L Hopital's rule works in a specific case; again the main topic related to their questions is L' hopital's rule, and a L'Hopital's rule tag would have been useful to them. Search "l'hopital" on the search option and many such questions come up.

• Can you explain why you think that this tag is necessary? L'Hospital's rule is a tool for computing limits. Generally, someone here posts a question about a limit, and expects folk to find that limit for them. The tools used to do this are typically irrelevant. There are folk who want to do things without using certain tools, for which the limits-without-lhopital tag exists. I don't, however, see a compelling reason to include a "lohpital" tag. That said, my mind is open, and I'm willing to be convinced. – Xander Henderson Jan 8 at 0:06
• @XanderHenderson please see my edit. Unfortuantely I do not have any links of other's questions that include L Hopital's rule at the moment. – A-Level Student Jan 8 at 9:12
• So the clarification you have added now can be summarized as: The tag would be for questions about L'Hospital's rule - and not for computations of limits L'Hospital's rule. (Unless they are in some way specific to LH - for example, asking why LH works/does not work in some limit.) – Martin Sleziak Jan 8 at 9:13
• I have collected some possible examples of such questions here in chat. Maybe also some other users might have suggestions (or at least say whether this would be the kind of questions suitable for that tag). – Martin Sleziak Jan 8 at 9:54
• @RodrigodeAzevedo Although I do think that my suggested tag would be useful, and the one you suggested too based on how many questions you showed included it, I think on the whole Math Meta do listen to users' suggestions. I find the SU refeernce funny though, thanks for it :) – A-Level Student Mar 12 at 12:53
• @A-LevelStudent What if most users do not particularly like math (but need to pass a few courses) and never bother to create an account from which they can offer suggestions or upvote / downvote proposals? They may be the ones clicking on ads that keep the lights on around here. – Rodrigo de Azevedo Mar 12 at 17:55
• @RodrigodeAzevedo that's a scary thought but we don't have ads on math.SE right? only the community ads – Calvin Khor Mar 13 at 2:15
• @CalvinKhor I don't see ads here, but I see ads on other SE sites where I have few rep points. I believe in making Math SE easy to use and useful for people for whom mathematics is utter torture. Having more tags to help people find questions similar to the ones in their homework would be a step in that direction. – Rodrigo de Azevedo Mar 13 at 3:14

In a sense, rank-$$1$$ matrices are the "atoms" with which "composite" matrices are built. Moreover, factoring polynomials and solving some combinatorial optimization problems can be reduced to finding a rank-$$1$$ matrix. Thus, I propose that tag be created.