Finite Sets Proof on Domains
86421
Proof of the definition of cardinal exponentiation
35692
The set of all finite subsets of the natural numbers is countable
45219
Proving that $C$ is a subset of $f^{-1}[f(C)]$
77735
When $\Bbb Z_n$ is a domain. Counterexample to $ab \equiv 0 \Rightarrow a\equiv 0$ or $b\equiv 0\pmod n$
45792
Rigorous proof that surjectivity implies injectivity for finite sets
49157
First order theory - define a domain with an even number of elements
107383
Derived sets - prove $(A \cup B)' = A' \cup B'$
139826
arbitrary large finite sums of an uncountable set.
1020
Proving that $\mathbb{Z}[\sqrt{2}]$ is a Euclidean domain
84149
Prove that an infinite ring with finite quotient rings is an integral domain
4383
Finitely generated monoids - how to show that there is not first order set axiomatizing them.
94365
How to prove that if $D$ is countable, then $f(D)$ is either finite or countable?
32441
How to prove or disprove statements about sets
36044
Show $\Bbb R ^n$ with a finite set removed is still connected.
84936
The set of all finite sequences of members of a countable set is also countable
66398
Union of a finite set and a countably infinite set is countably infinite
154495
Prove that a nontrivial subring of a ring that is a domain has the same identity