Geometry: Logic

Question

Prove the following statements proving the laws of logic; Modus Ponens, Modus Tollens, Disjunctive Inference, and DeMorgan's Laws.

Given: A → B, C → ~ B, C V N, A

Prove: N

Answer 1

A→B and A (therefore B by Modus Ponens)

C→-B and B (therefore ∼C by Modus Tollens)

C v N and ∼C (therefore N by disjunctive syllogism)