For what conditions on sets $A$ and $B$ the statement $A - B = B - A$ holds?
33542
When is $A- B = B- A$?
80009
Prove that $| |a|-|b| | \le |a-b|$
70307
$(A\cap B)\cup C = A \cap (B\cup C)$ if and only if $C \subset A$
7416
Let $ A $, $ B $ and $ C $ be sets. If $ A \cup B = A \cup C $ and $ A \cap B = A \cap C $, then show that $ B = C $.
107383
Derived sets - prove $(A \cup B)' = A' \cup B'$
86030
Prove or disprove - If a divides b and b divides a does a=b
126897
Showing the set $A+B$ is closed.
142993
Proof of A ⊆ C and B ⊆ C ⇔ A ∪ B ⊆ C
77902
If $A,B,$ and $C$ are sets, then $A\times(B-C)$ = $(A \times B)$ $-$ $(A \times C)$.
62172
Why does $-b < a < b \iff |a| < b$?
155884
What are the conditions on $\text{tr}(AB) \leq \text{tr(A)} \text{tr(B)}$ to be true?
131983
Prove that $A \subset B$ if and only if $A \setminus B = \emptyset$
116527
Validating a proof for necessary and sufficient conditions on sets A & B such that $P(A) \cup P(B) = P(A\cup B)$
21663
Bijection between power sets of sets implies bijection between sets?
90566
There exists surjections from A onto B and vice versa, and there is no bijection between the sets?
144266
set theory proof of $A\cap B = A \setminus(A\setminus B)$
53101
Is it true that the relation |A| < |B| is a sufficient condition for claiming that $f$ is a bijection?