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16h
comment Properties of distributive lattices and congruences.
I can't say it's plausible or not, because I still don't know what it means. "The elements that are delimited by $a$ and $b$ that are part of the congruence" is Greek to me. Sorry.
17h
comment Properties of distributive lattices and congruences.
What does $\theta(a,b)$ mean?
23h
comment Complement of a bipartite graph
Perhaps more simply, $n\le4$ follows from the inequality $\chi(G)\chi(\bar G)\ge n$.
1d
awarded  elementary-set-theory
1d
revised When are two direct products of groups isomorphic?
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1d
comment When are two direct products of groups isomorphic?
@Seirios: Vipul Naik seems to have rediscovered the argument Lovász came up with in the 1960s.
1d
revised When are two direct products of groups isomorphic?
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1d
answered When are two direct products of groups isomorphic?
2d
comment Can Aleph Numbers be multiplied?
@Meelo I suppose so, but wouldn't it look sillier to have to write $\alpha^{\beta+\gamma}=\alpha^\gamma\alpha^\beta$ instead of $\alpha^{\beta+\gamma}=\alpha^\beta\alpha^\gamma$?
2d
comment Can Aleph Numbers be multiplied?
@Meelo According to the traditional notation for ordinal multiplication (maybe it changed recently?), $2\omega=\omega$ and $\omega2=\omega+\omega\gt\omega$.
2d
comment Is there a notation for being “a finite subset of”?
Well then woule $A\subseteq_{fin}B$ work?
2d
comment Is there a notation for being “a finite subset of”?
In that case, I'd go with something like $A\underset{fin}{\subseteq}B\subseteq\mathbb N$. Easier on the reader than using some arbitrary symbol; easier to remember.
2d
answered Is there a notation for being “a finite subset of”?
2d
answered Surprising applications of topology
2d
revised What would be an example of a magma such that $x\cdot(x\cdot x)\neq (x\cdot x)\cdot x$?
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2d
revised Prove that a function diverges to infinity if its derivative has a positive lower bound for all $x$ on a closed ray $\left[ a,\infty \right)$.
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2d
answered Prove that a function diverges to infinity if its derivative has a positive lower bound for all $x$ on a closed ray $\left[ a,\infty \right)$.
Jan
27
revised What is the minimum number of painted edges in the chessboard?
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Jan
27
comment Least value of an Expression?
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Jan
27
answered What is the minimum number of painted edges in the chessboard?