The conversation between human and AI assistant.
How can I prove that (A × B) − (C × D) = (A − C) × B ∪ A × (B − D)?
And how does that help?
Now we can use the fact that set union distributes over set difference, and we can write the right side as (A × B − C × B) ∪ (A × B) − (A × D).