Part A: Prove the following sequents using primitive rules or derived rules. (14 pts) 1. (AAB)-C, A-C, B - C 2. A - (B - C), TF, D- A, - CV - F, D - -B 3. C - (DV-(AVB)), - A-B, - -D--C 4. A-(B-C), A-B, -C-(AVD) } CVD Part B: Prove the following sequent using only primitive rules. (5 pts) 1. L - S, F - V, SV - V, F LV -F Part C: Prove the following theorem using only primitive rules. (3 pts) 1 . ( P - Q ) - (( P - Q) A ( Q - P) )