Referring the truth table in problem 6, list the wffs that are equivalent to a b. 8) referring the truth table in problem 6, list the wffs that are equivalent to the negation of a 8. 9) assign truth values to a, b, and c to prove that (a a b) v c is not equivalent to a a (b v c). c: b: a: (circle one of true or false) (aa b) v c is true or false (a a b) is true or false aa (bv c) is true or false (bv c) is true or false