4:56 AM
I suppose tag did not exist when the question was posted.
Since you have added the tag and you care about tagging of set-theory-related questions a lot, I thought it might be polite to let you know.
I would maybe keep both, but there is 5 tags limit.
17

What are the most prominent uses of transfinite induction in fields of mathematics other than set theory? (Was it used in Cantor's investigations of trigonometric series?)

3 hours later…
7:58 AM
The tag was created in August 2015 by David C. Ullrich.
When I try SEDE to check the oldest occurrences of , it seems that it was created by Yuval Filmus in 2011: data.stackexchange.com/math/query/542457/… data.stackexchange.com/math/query/787716/…
Or maybe we could wait a bit before considering changes to these tags - until David C. Ullrich gets the taxonomist badge :-) Only 4 questions to go.
@DavidC.Ullrich Since you are the creator of the (transfinite-induction) tag, I though it might be polite that I have started a discussion on meta related to this tag. — Martin Sleziak 2 mins ago
@YuvalFilmus Since you are the creator of the (transfinite-recursion) tag, I though it might be polite that I have started a discussion on meta related to this tag. — Martin Sleziak 32 secs ago

0

At the moment we have two tags transfinite-induction and transfinite-recursion. These topics are rather close. I can imagine a reasonable question which could be tagged with the tags transfinite-induction, transfinite-recursion, ordinals, elementary-set-theory. Having only five spots for tags, t...

5 hours later…
12:51 PM
Sep 3 '17 at 12:43, by Martin Sleziak
@Martin It's been the practice for years. I do not participate in chat, and try to avoid commenting in meta unless essential. Thank you. — Andrés E. Caicedo 12 secs ago
So it seems that I provoked a rare exception. :-)
Induction and recursion are different things, even if there are some (formal) similarities. Mixing them up tagwise will only help confuse those that are not clear on the distiction. — Andrés E. Caicedo 10 mins ago

1:41 PM
Both of them found as the first post with this tag - David C. Ullrich's the same one that I have mentioned here.
8

If $I=[a,b)$ we write $|I|=b-a$ for the length of $I$. Given a theorem of Caratheodory, the tricky part in showing the existence of Lebesgue measure is this: Lemma If $[0,1)$ is the disjoint union of a countable collection $(I_j)$ of half-open intervals then $\sum_j|I_j|=1$. It's easy to conclu...

@DavidC.Ullrich Since you are the creator of the (transfinite-induction) tag, I though it might be polite that I have started a discussion on meta related to this tag. — Martin Sleziak 6 hours ago
@MartinSleziak I am? Don't recall creating that tag... — David C. Ullrich 7 mins ago
@DavidC.Ullrich As far as I can tell, this was the first question having this tag, more details can be found here. (Maybe we will see in a while whether you get taxonomist badge when the tag gets 50th question - that would be a confirmation.) In any case, the main point was that the tag-creator might be interested in discussion about the tag, which is why I posted the above comment. — Martin Sleziak 30 secs ago
In case it is interesting in connection with the above exchange: Can you tell who created a tag
7

I recently created a tag, will anywhere show that it was created by me? Same with other tags, can I see who created them?

2:18 PM
@MartinSleziak Oh, I wasn't disputing the idea that I created the tag, just don't recall. That was years ago, before I had any idea that things are sometimes controversial around here... — David C. Ullrich 2 mins ago
0

For the record, it won't bother me regardless of what's done about this. I don't like the idea of making one a synonym for the other. It bugs me when people talk about "inductive" definitions - people don't talk about "recursive" proofs, but if they did that would bug me too. Structuring our ta...