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Oct
8
comment The “Empty Tuple” or “0-Tuple”: Its Definition and Properties
There is no need to "define" (): you can use that symbol to denote the only element of $X^0$ and be happy with that.
Oct
8
comment Calculating the expected winner of a Penney's Game using a Markov Chain.
Please do not destroy content in that way. This question has an answer —an accepted one, in fact; while you may no longer be interested in this question, someone invested time and effort to respond, and it is rather unpolite to try to brush it off in that way.
Oct
8
revised Calculating the expected winner of a Penney's Game using a Markov Chain.
rolled back to a previous revision
Oct
7
comment sorting young's tableau better than n^3
Sorting all numbers in what way? Presumably, the shape of the diagram matters? You should try to explain clearly and completely what it is you want to do, for otherwise the chances of anyone being able to help you are quite small!
Oct
5
revised Cardinality of a Quotient Ring
added 19 characters in body
Oct
5
comment Cardinality of a Quotient Ring
The matrix in the first paragraph is determined uniquely by $a$, as it is the matrix of the map $m_a$. You can choose too multiply on the left or on the right, but for each side you'll have a different matrix (although the two are related in a very simple way: which one?)
Oct
5
revised Cardinality of a Quotient Ring
edited body
Oct
5
answered Cardinality of a Quotient Ring
Oct
5
answered Prove this plane algeraic curve is not a differentiable manifold
Oct
4
awarded  Taxonomist
Oct
2
comment What happens if we rotate the kernel of an integral operator?
This follows simply from the change of variables formula, using the fact that Lebesgue's measure invariant up to a scalar under linear maps.
Sep
30
awarded  Explainer
Sep
30
revised Jacobi identity - intuitive explanation
added 604 characters in body
Sep
30
answered Jacobi identity - intuitive explanation
Sep
30
comment To prove that $A$ has a one-dimensional eigenspace , where $A \in SO(3)$ , $A \ne I$
@orangeskid, please do add that as an answer.
Sep
30
revised Submodule iff subgroup?
added 2 characters in body
Sep
30
answered Submodule iff subgroup?
Sep
28
comment Composite function of $R$-module
To add drama, let $M$, $N$ and $P$ be any modules, let $k:P\to M$ be any function, and let $f$, $g:M\to N$ be both the zero map (you can also take $f:M\to N$ to be any function and $g:x\in M\mapsto -f(x)\in N$).
Sep
28
comment Composite function of $R$-module
More generally, pick $n>1$ and $1\leq m<n$, let $M=N=P=\ZZ/n\ZZ$, let $f:M\to N$ be multiplication by $m$ and $g:M\to N$ be multiplication by $n-m$, and let $k:P\to M$ be any function.
Sep
28
answered Composite function of $R$-module