1. Use the truth-tree method to determine whether the following argu- ment is tr

1. Use the truth-tree method to determine whether the following argu- ment is truth-functionally valid or invalid. If it is invalid, recover a truth-value assignment that shows this. (10 marks)
P1 (J T) J P2 (T J) T
C ⇠J _ ⇠T
2. Use a truth tree to determine whether the sentence
([(C D) & (D E)] & C) & ⇠E
is truth-functionally true, truth-functionally false or truth functionally indeterminate. (10 marks)
3. UsingSD,deriveD&⇠Dfrom{(⇠A&B)(B⌘D),B(C&⇠A), ⇠D & B}. (10 marks)
4. Using SD, demonstrate that (A & C) _ (B & C) follows from (A _ B) & C. (10 marks)
5. Using SD, demonstrate that A [B (A B)] is a theorem. (10 marks)