Proving $a\mathbb{Z}\cap b\mathbb{Z}=[a,b]\mathbb{Z}$
60777
Prove $\, a_1 \Bbb Z \cap \dotsb \cap a_r \mathbb{Z} = {\rm lcm}(a_1, \ldots, a_r) \Bbb Z$
77361
How to prove $|H|[K:K \cap (g^{-1}Hg)]=|K|[H:H \cap (gKg^{-1})]$?
115460
Proving $a\mid b^2,\,b^2\mid a^3,\,a^3\mid b^4,\ldots\implies a=b$ - why is my approach incorrect
26766
Proving : $A \cap (B-C) = (A \cap B) - (A \cap C)$
63535
Prove that if $A – C = B – C$ and $A\cap C = B\cap C$ then $A = B$
116215
Prove that $P(A \cap B\mid C)=P(A \mid (B \cap C))P(B\mid C)$
7316
How to prove that $z\gcd(a,b)=\gcd(za,zb)$
37398
Proof that$ (a+A)\cap A=\varnothing$ if $A$ is countable
144502
Showing that $A\cap B = A\setminus (A\setminus B)$
49143
Showing $A \subset B \iff A\cap B=A$
140446
Prove that $A \smallsetminus (A \smallsetminus B) = A \cap B$
59134
Proving idempotent elements in $\mathbb{Z}_n$
144266
set theory proof of $A\cap B = A \setminus(A\setminus B)$
137739
Prove that the group isomorphism $\mathbb{Z}^m \cong \mathbb{Z}^n$ implies that $m = n$
102917
Proving statement - $(A \setminus B) \cup (A \setminus C) = B\Leftrightarrow A=B , C\cap B=\varnothing$
104068
Prove that $\forall a,b\in\mathbb{C} \exists c,d \in \mathbb{C}: c+d = a \land cd = b$
128760
If $A$ and $B$ two $n\times n$ matrix such that $AB=BA$, then $\dim(A\cap B)$?