Tag merging and synonyms

Question

This is half a question, half an announcement. I will be going through the list of tags and merging particularly bad ones (e.g. ones that aren't mathematical or are too specific) into the tag [tag-removed]. I will also be creating tag synonyms. Any suggestions for mergers or synonyms should go into this thread.

Roughly speaking, here is my general policy: if I can't imagine a person classifying a tag as either interesting or ignored, I'm getting rid of it.

Edit: This thread and the tag changes archive have been merged for simplicity.

Edit2: I've started a new summary thread. Moderators: please allow sufficient time (at least 1 day) for discussion on "non-trivial" proposals, before actual implementation (some of such "non-trivial" ones are still not yet resolved, see the list below). After implementation please first comment to indicate implementation (to get a date stamp), then delete the answer to unclutter, and add a line to the summary thread.

Answer 1

Summary Thread for Implemented Changes

(Please do not edit this answer unless you are a moderator. All proposed changes should be added as new answers to the question. Users with 10K+ reputation will still be able to see the original dates of proposals and implementations.)

One should also note that there exists a page on the StackExchange platform specifically listing all tag synonyms and proposals for tag synonyms. Any user with 2.5K+ rep can go and vote up/down proposals for synonyms.

The following is sorted alphabetically by the name of the deprecated tag. Format is "(deprecated tag name) s/m (principal tag name)" in the case of synonyms or mere merging without synonyms; and "(deprecated tag name) d" in the case of removed tag names.

• action d
• addition s arithmetic
• ag.algebraic-geometry m algebraic-geometry
• analytic m analyticity
• art-theory m art
• bases d
• big-o s asymptotics
• books s reference-request
• bundles d
• cardinality m elementary-set-theory
• closure d
• complex-conjugate m complex-numbers
• complex-variables s complex-analysis
• complexity s computational-complexity
• continuum m real-analysis
• counter-examples s examples-counterexamples
• convex-sets s convex-analysis
• differential-manifold m differential-geometry
• division-algebra m division-algebras
• elementary d
• elementary-geometry m geometry
• ellipse s conic-sections
• enumeration s combinatorics
• equations d
• examples s examples-counterexamples
• expectation m probability
• explanation s intuition
• exterior d
• field-extensions m field-theory
• golay-code m coding-theory
• gradient d
• group m group-theory
• hyperbolic-functions m trigonometry
• impossibility-proof d
• infinite-series m sequences-and-series
• iterated-functions m dynamical-systems
• jargon s terminology
• lie-algebra s lie-algebras
• linear m linear-algebra
• linear-combination m linear-algebra
• manifold s manifolds
• materials-science d
• measure d
• metric s metric-spaces
• middle-school d
• mobius-strip d
• mobius-transforms m complex-analysis
• normal-distibution m normal-distribution
• numeral-systems s number-systems
• numerical-analysis s numerical-methods
• parabola s conic-sections
• pedagogy s teaching
• primitive-polynomial m polynomials
• progression s sequences-and-series
• properties d
• putnam s contest-math
• pythagorean-triples d
• (ramanujan) d
• random-variable m probability
• real m real-analysis
• recursion-theory s computability
• riddle s puzzle
• riemann-surface s riemann-surfaces
• rings s ring-theory
• semi-group s semi-groups
• sigma-algebra s measure-theory
• signal-analysis s signal-processing
• sum d
• summation m sequences-and-series
• symbolism m notation
• theoretical-mathematics d
• topology s general-topology
• uniform-distribution m probability
• wedge-product s exterior-algebra
• wolframalpha s wolfram-alpha

Answer 2

During my first 3 weeks here I have encountered a few peculiarities:

The tag golay-code has only a single post. I don't know for how long we commonly wait to have meaningful statistical evidence, but it sounds like a merger with coding-theory is due.

Another thing that I found odd was the tag division-algebra. Of the 5 posts carrying that tag one was about octonions, the rest were (junior) high school level questions about the role of division in school level algebra. I rather got that the intention of the tag was to collect questions related to division algebras aka skewfields aka division rings, but I may be wrong. The confusion may stem from the fact that this tag has no wiki entry. If it is meant to be part of abstract-algebra, then I could write a wiki for it.

Answer 3

By the tag wiki, it looks like algebra and abstract-algebra are being used the same way. Should the former be deprecated in favor of the other?

Also, there has been previous discussion on this topic, but it seems that no conclusion was reached.

Should the question be brought up again on meta.math?

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EDIT (M.S.): As you have probably noticed, algebra is empty now (already for some time).

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EDIT (J.M.): That damn algebra tag has kept popping up the last few days... I've been able to remove it, but it seems I'm the only guy who gives a rat's ass about these things...

(Later)

Maybe that last bit was somewhat harsh. The thing popping up just had me frustrated. I do remember asking if we can have a blacklist for it, and Willie said that he'd rather hope that people would be smart enough not to use that tag again. Oh well.

(Much later)

I see somebody bothered to write a tag-wiki (again?!) but didn't bother to remove said tag from the questions... maybe I should stop caring; it just raises my blood pressure.

Answer 4

Chronological Summary Thread for Implemented Changes

Taking on Willie's notation, the following is sorted chronologically by the time (newer is higher) of the action taken. Format is "(deprecated tag name) s/m (principal tag name)" in the case of synonyms or mere merging without synonyms; and "(deprecated tag name) d" in the case of removed tag names.

July, 2011

July, 9th

• riemann-surface s riemann-surfaces

July 7th

• jargon s terminology

July 6th

• lie-algebra s lie-algebras

July 5th

• theoretical-mathematics d
• differential-manifold m differential-geometry
• linear m linear-algebra
• linear-combination m linear-algebra

Actions B.C.

• action d
• ag.algebraic-geometry m algebraic-geometry
• bases d
• big-o s asymptotics
• books s reference-request
• cardinality m elementary-set-theory
• complex-variables s complex-analysis
• continuum m real-analysis
• division-algebra m division-algebras
• elementary d
• elementary-geometry m geometry
• ellipse s conic-sections
• enumeration s combinatorics
• equations d
• expectation m probability
• explanation s intuition
• field-extensions m field-theory
• golay-code m coding-theory
• gradient d
• group m group-theory
• hyperbolic-functions m trigonometry
• impossibility-proof d
• iterated-functions m dynamical-systems
• linear m linear-algebra
• materials-science d
• measure d
• metric s metric-spaces
• mobius-strip d
• mobius-transforms m complex-analysis
• normal-distibution m normal-distribution
• numerical-analysis s numerical-methods
• parabola s conic-sections
• pedagogy s teaching
• primitive-polynomial m polynomials
• progression s sequences-and-series
• properties d
• pythagorean-triples d
• random-variable m probability
• real m real-analysis
• recursion-theory s computability
• rings s ring-theory
• semi-group s semi-groups
• signal-analysis s signal-processing
• sum d
• summation m sequences-and-series
• symbolism m notation
• topology s general-topology
• uniform-distribution m probability
• wedge-product s exterior-algebra

Answer 5

Do we really need both the integration and integral tags?

If not, could we merge one into the other?

And if so, could someone give a good explanation of the difference between the two?

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Edit by J.M.: If we do merge these two, which name do we keep? (A rewrite of the tag blurb and tag wiki might also be in order.)

Answer 6

I find number lacking in utility. It seems that every post which has this tag is either closed or could easily be retagged. I would be happy to suggest alternative tags for posts tagged as number.

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EDIT by Srivatsan (Nov 29): Bumping up the post. I propose that we start removing the number tag from posts.

Answer 7

In my opinion propositional-calculus and recently created tag propositional-logic should be synonyms.

(If the intended use of propositional-logic is different, it should be clarified in tag-wiki, which is currently empty. Based on two questions which currently have this tag, I think the usage is the same as propositional-calculus, therefore I made the above proposal. If you think that these two tags should have different purpose, please, explain it in the comments and consider editing tag-wiki.)

Answer 8

Can we please delete proof-strategy?

This feels like a meta tag.

Answer 9

I think context-free-grammar should be merged into and synonymized to context-free-language.

Answer 10

I don't see the need for having both eigenvalues and eigenvectors as separate tags.

Potential names for the merged tag: eigensystems, eigenanalysis, eigendecomposition. If there are better terms for this, please propose them in the comments.

Here is some relevant empirical data from the Google Ngram Viewer.

Answer 11

inversion is quite the mess; some of it is for inverting matrices and some of it is for inverting functions. I'm not really pushing for a deletion, but is there a neat way to resolve this?

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Added [by Srivatsan]: I propose to delete the inverse tag.

This tag is currently used in a variety of different senses: inverse of a ring/group element, matrix inverse, function inverse, inverse Laplace transform, inverse cdf, etc. However, it seems that all 30 questions under the tag are safely covered by the other tags.

Answer 12

I think the posts tagged as real-number-computation can probably be retagged also, and this tag should be deleted.

Answer 13

I proposed creating partial-differential-equations as a synonym for pde in the chat, where it met with some support. Rationale:

• pde is about the only commonly used tag which is an abbreviation. Judging from the other tags they see, new users would not expect abbreviations in tags.
• While "PDE" is a completely standard abbreviation for mathematicians, it is less so for students in service-level courses, who supply a large number of PDE questions.
• When a user tries to tag their question with (partial-diff...) and finds no match, they are likely to delete "partial" and mistag the question as (differential-equations). This is one of the more common mistags I see.

Answer 14

Can we kill the completeness tag? A look at the five questions currently tagged as such already indicates two-and-a-half different meanings for (completeness). That is without considering geodesic completeness in geometry, completeness of logical systems, completeness of vector fields, completeness of measure spaces, completeness of an orthonormal set of vectors in a Hilbert space, completeness for graphs, completeness of partially ordered sets, ... and I am sure there must be others.

Edit: [A.K]: March $10^{\text{th}}$, I have ruthlessly butchered this tag away!

Edit II [A.K]: March $20^{\text{th}}$, I have killed the tag again. Please remove it, and/or point to this post when it comes back to life the next time.

Answer 15

Both presentation and group-presentation are used for the same topic, the later has now a nice tag-wiki (thanks to Alexander Gruber). I think they should be synonyms.

EDIT: They are synonyms now. (Thanks to Willie Wong.)

Answer 16

This is a good initiative. Please have a look at my old question and make decisions for the tags mentioned therein.

Answer 17

There is a counting tag. I feel it can be merged with the tag combinatorics. Can a moderator implement this?

Answer 18

Can anybody give a good reason why the numerical-methods and numerical-analysis tags are separate? I would say retain one or the other, but certainly not both.

Answer 19

I'm not too keen about the birthday tag; something like calendar might be more suitable, unless one has a better name for the tag we can assign to calendrical questions.

Answer 20

I think the current tag recursive is not as good as recurrence or even better recurrence-relation.

Answer 21

I find the tag natural-number unneeded, with only 11 questions tagged under it, some of these questions belong to elementary-set-theory (however tagged under set-theory) and others fit well under currently available tags.

I see no actual use of the tag for real questions that are not fitting well and properly under other tags of the currently tagged questions.

It should be deleted after verification that all questions fit under other tags currently present, personally I think it is fine (except for one question tagged only under natural-number which I am uncertain how to classify).

Answer 22

Are we ready to follow up the suggestions in the following answer?

The tags [recursive] and [recurrence-relation]

Answer 23

Do we really need normal-distribution, geometric-distribution, and probability-distributions as three separate tags?

Answer 24

The tag expected-value was recently created. We used to have an expectation tag, but we decided that it was sufficiently covered by probability, and so expectation was merged into probability several months back. In keeping with this decision, I think expected-value should also be merged with probability.

Answer 25

I am very much unfamiliar with the topics, however do we really need both 3-manifolds and 4-manifolds?

Edit:
As we agreed that low-dimensional-topology is better, I wonder... what is the difference between that and manifold? I'm certain that some difference exists to justify the two tags to be separated. Is it possible for someone to write it into the Tag Wikis (esp. into the excerpts) to help [me] distinguish between the two?

Edit II:
The tag 3-manifolds came back. I tried synonymizing it with low-dimensional-topology, alas I could not since there is only one question in the tag with one vote and no answers. So in fact, no one can suggest a synonym!

Answer 26

Shouldn't convex-sets and convex-analysis be synonyms?

Updated: As Willie Wong suggests, the more general tag "convexity" would probably be even better.

Updated, again: On further reflection, I think convex-analysis is the better general term. We already have 9 other tags called "[something]-analysis", and so convex-analysis would be more consistent with our already-existing tags than convexity would.

Answer 27

This question was tagged [sangaku]. Merged to [puzzle].

Answer 28

This question was tagged [iteration]. Merged to [tag-removed].

Answer 29

Is there a need for all three of k-theory, topological-k-theory and algebraic-k-theory?

Answer 30

recursion-theory (1 question) should be merged as a synonym of computability (36+ questions). Some people also use recursive for questions about computability; I guess someone will have to look at those by hand, because that last tag could also be about recurrence relations or other forms of recursion.