# Homework due Monday June 3

If you did not get 6 out of 6 on problem 3 from the exam please redo it and turn in a properly written proof.

Here is the problem:

Let $A$, $B$ and $C$ be sets.  Prove that

$A \cup (B\cap C) = (A \cup B) \cap (A\cup C)$

Note that you must reason about arbitrary sets — you cannot prove this “by example”.  Likewise if you use a truth table then you need to explain why it is relevant and make sure it is a truth table for statements.  It makes no sense to say that $A$ is true or false if $A$ is a set.