In: Advanced Math
Prove verbally without referencing a Venn diagram, can use a Vennn diagram to visually see it but cannot be a reference in proof.
a) Let A be a set. Prove that A⊆ A.
b) Let A, B, and U be sets so that A ⊆ U and B ⊆ U. Prove that A ⊆ B if and only if (U \ B) ⊆ (U \ A)
c) Let A, B be sets. Prove that A \ (A ∩ B) = A \ B
d) Let A, B be sets. Prove that A \ (B \ A) = A