Prove that the symmetric difference is associative using only the properties of $\cup$ and $\cap$
12459
Associativity of symmetric difference of sets
49578
Proving $a\mathbb{Z}\cap b\mathbb{Z}=[a,b]\mathbb{Z}$
138069
Proof that $\bigcap_{a\in A} \bigg(\, \bigcup_{b\in B} F_{a,b} \, \bigg) = \bigcup_{f\in ^AB} \bigg(\, \bigcap_{a \in A} F_{a,f(a)}\,\bigg) $
28003
How to prove $A+ A^T$ symmetric, $A-A^T$ skew-symmetric.
104349
Proof by induction involving symmetric groups
115606
Proofs involving $ (A\setminus B) \cup (A \cap B)$
26302
Prove that $(X \cap Y) \cup Z = (X \cup Z) \cap (Y \cup Z)$
47670
Algebraic proof of $\sum_{i=0}^k{{n \choose i}{m \choose {k-i}}}= {{m+n}\choose k}$
56399
Proof for $A \cup B = B$ if and only if $A \subset B$
64586
How to prove that $\neg((A\cap B)\cup (\neg A \cap C)) = (A\cap\neg B)\cup (\neg A\cap \neg C)$
100303
A necessary and sufficient condition for $A\cap(B+C)=(A\cap B)+C$ to hold for submodules
75604
Proof that $\partial(A\times B) = ((\partial A)\times B)\cup (A\times(\partial B))$
128060
Proof that the relation $5 \mid (a + 4b)$ is symmetric and transitive
45958
Proof that the Euler characteristic is additive
56370
Associative operation on a set $S$
80996
A canonical construction proving $\left|HK\right| = \left|H\right|\left|K\right| / \left|H \cap K\right|$?
123890
Show $A\setminus (A\cap B)=(A\cup B)\setminus B$