Let A and B be any arbitrary sets, then A′ − B′ is equivalent t

It seems like you didn't finish your question. However, based on what you've provided, it seems like you're asking about set theory.

If A and B are any arbitrary sets, then A' (the complement of A) minus B' (the complement of B) is equivalent to B - A.

Here's the step by step explanation:

1. A' represents all elements not in A.
2. B' represents all elements not in B.
3. A' - B' represents all elements that are not in A but are in B.
4. This is equivalent to B - A, which represents all elements that are in B but not in A.

Please provide the complete question if you need a more specific answer.