I have a set identity: $(A \cap B) \cup C = A \cap (B \cup C)$ if and only if $C \subset A$. I started with Venn diagrams and here is the result: It is evident that set identity is correct. So I
Union & Intersection of Sets Cardinal Number of Set
The ( left( A cap B ^ { prime } right) ^ { prime } cup ( B cap C
Complement (set theory) - Wikiwand
If [math]A, B[/math] and [math]C[/math] are three sets, how to
Prove `A cup (B cap C)=(A cup B) cap(A cup C)`
Principle of Inclusion and Exclusion (PIE)
DM4CS Methods of Proof for Sets