There has just recently ben created a double-factorial tag. I don't think we should have another tag just for this and that the tag factorial suits it well enough. I propose we change the tag wiki for factorial to include double factorials and remove the double-factorial tag.
The tag-excerpt for double-factorials looks like this:
Series, integrals, and formulas involving the double factorial. The double factorial is defined as $n!!=n(n-2)(n-4)\cdots(n-2\lfloor n/2\rfloor)$. It is usually applied to odd numbers since $(2n)!!$ can easily be written as $2^nn!$.
Series, integrals, and formulas involving the double factorial. The double factorial is defined as $n!!=n(n-2)(n-4)\cdots(n-2\lfloor n/2\rfloor)$. It is usually applied to odd numbers since $(2n)!!$ can easily be written as $2^nn!$.
For odd numbers, we have $$ (2n-1)!!=\frac{(2n)!}{2^nn!} $$
I wanted just to copy them somewhere - I am not sure whether there is an easy way to find the original tag-info after a tag has been merged/synonymized/deleted...
The formal-proofs tag currently has no tag wiki. In my opinion this might invite people to use the tag for any question asking for a (more or less formal) proof. Very similar to the way the proof tag was used before it got removed and blacklisted. My personal assumption, however, was that formal-...
I created the tag (formal-proofs) with intent that it should be used when people are asking for a formal proof of something within a formal system, the most common occurrences of this are natural deduction and Hilbert system kind of proofs. It could perhaps be used sometimes in conjunction with (proof-theory) if people are trying to related a formal proof to its stance in the meta-theoretic context, but mainly it's independent of proof theory. All of the above is just what I intended for the tag. I don't think it is a bad tag and I most certainly feel that this or a similar one is required. — Git Gud26 mins ago
There has just recently ben created a double-factorial tag. I don't think we should have another tag just for this and that the tag factorial suits it well enough. I propose we change the tag wiki for factorial to include double factorials and remove the double-factorial tag.
