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6h
comment Prove or disprove: For non-negative integers $m$ and $n$, $m!n! = (mn)!$
@Ben You mean, if both $m$ and $n$ are greater than one, then you don't have $(mn)!=m!n!$. If $m\gt1$ and $n=1$ then $(mn)!=m!n!=m!$.
12h
comment Disjoint cycle Decomposition.
How do you know that $a_1*a_2=\epsilon$? What does that even mean? What is $a_1$ and what does $*$ mean?
1d
comment If $F$ is finite then is $\sigma(F)$ also finite?
$\sigma(G)\cup A_{n+1}$ isn't even a family of sets. Did you mean $\{A_{n+1}\}$ instead of $A_{n+1}$?
1d
comment F is a vector space and U, V, and W are subspaces of F. Prove that $U\bigcup V\bigcup W$ is a subspace of F if and only if $U,V\subset W $.
Why would it matter whether $U,V\subset W$ or $U,W\subset V$ or $V,W\subset U$?
2d
comment If a group G has only the trivial group and G itself as its subgroup, can we be sure that G has prime order?
@Rescy_ $G=\{e\}$ seems to be a counterexample, unless you consider $1$ to be a prime number.
2d
comment Is the sequence $(-1)^n$ eventually or frequently in the set {$1$}
So you want to figure out whether, for every $N\in\mathbb N,$ there exists $n\ge N$ such that $(-1)^n\in\{1\}$, i.e., such that $(-1)^n=1$? Have you tried any examples? Can you fin $n\ge1$ such that $(-1)^n=1$? Can you find $n\ge10$ such that $(-1)^n=1$? How about $n\ge100$?
2d
comment Counting models that satisfy PL sentences
Piecewise linear sentences????
2d
comment Two candidates, A & B, are running for president. What is the probability that candidate A beats candidate B?
If both candidates had $80$ votes and need $115$ to win, then if A wins $2$ and B wins $3$ of the remaining states, both candidates win. If your assumptions allow the possibility of both candidates winning, why is it not intuitively pleasing that the probabilities add up to more than $1$?
Feb
7
comment Familiar spaces in which every one point set is $G_\delta$ but space is not first countable
Good. I'm not familiar with Munkres's text. Just out of curiosity, is there no example of a non-first-countable topology on $\mathbb N$ in the first 30 sections?
Feb
7
comment Familiar spaces in which every one point set is $G_\delta$ but space is not first countable
Yes, but how familiar is it?
Feb
7
comment Familiar spaces in which every one point set is $G_\delta$ but space is not first countable
It is hard to guess what spaces are familiar. Maybe you could post a link to the answers on this site with unfamiliar examples, so we don't duplicate any of those? I'm think of examples like "any countable T$_1$ space which is not first countable" or "box product of infinitely many lines" but I don't know if any of those are familiar.
Feb
6
comment show that the maximum degree of the graph is 6
Are you sure the problem is asking you to prove $\Delta(G)=6$ and not $\Delta(G)\le6$? I can think of an example with $\Delta(G)=0$.
Feb
6
comment show that the maximum degree of the graph is 6
Is $\Delta(G)$ the maximum degree of $G$?
Feb
6
comment Does $\Bbb P (A | B ) = \Bbb P(A | C) \Bbb P(C|B)$?
@CarlHeckman The way I see it, if I answer the question the guy asked, and it's not what he meant to ask, that's his problem and not mine. It's not like I'm getting paid to answer questions here. (I'm reminded of a Robert Sheckley story.)
Feb
5
comment Finding the data regarding the four racket games.
I notice $(T\cap Tt)$ is subtracted twice, maybe that's your mistake?
Feb
5
revised Counting the frequency of a flush hand in $7$-card poker
added 244 characters in body
Feb
5
answered Proof of $\aleph_0^{\aleph_0} = \mathbb{c}$ without using Cantor's $2^{\aleph_0} = \mathbb{c}$
Feb
4
answered Counting the frequency of a flush hand in $7$-card poker
Feb
4
comment Does $\Bbb P (A | B ) = \Bbb P(A | C) \Bbb P(C|B)$?
@GrahamKemp Well and good, but it only takes one example to prove an existential statement, and the question didn't seem interesting enough to look for all possible solutions.
Feb
4
comment Does $\Bbb P (A | B ) = \Bbb P(A | C) \Bbb P(C|B)$?
@CarlHeckman Sure. If you assume that Stan meant something completely different from what he said, you might as well assume that when I said "Yes" I meant "No". Me, I work from the default assumption that people mean what they say.