The conversation between human and AI assistant.
How can you prove that if A ⊆ B, then A ∩ B' = ∅?
That makes sense. Can you give an example of sets A and B where A ⊆ B and A ∩ B' is not equal to ∅?
Yes, let A be the set of even numbers and B be the set of natural numbers. Then, A is a subset of B, but A ∩ B' is not empty because A contains no odd numbers which are in B'. Therefore, A ∩ B' = {1,3,5,7,...}.