Using the transformation rules of system P, prove the following argument to be valid: (~A V ~B) ⊃ C, (C V ~D) ⊃ (E V F), ~A & ~E / :. F Using the transformation rules of system P, prove the following argument to be valid: ~(A ≡ C), ~(~A V B) / :. ~C Using the transformation rules of system P, prove the following argument to be valid: (A ⊃ ~B) ⊃ ~C, A ⊃ ~(E V F), B ⊃ E / :. A ⊃ ~C Using the transformation rules of system P, prove the following argument to be valid: (A V B) ⊃ ~C, ~(A ≡ B) / :. C ⊃ X Using the transformation rules of system P, prove the following proposition to be a tautology: (A ⊃ (B V C)) ⊃ (~C ⊃ (A ⊃ B))