Let B be a Boolean algebra with operations + and *, where 0 is the identity for + and 1 is the identity for *. If a in B, let bar(a) be the negation of a. Select each statement which is true.
1) bar(bar(a)) = a
2) a + bar(a) = 0
3) a * bar(a) = 1
4) bar(a + b) = bar(a) + bar(b)