Why is Q → P a logical consequence of ¬(P → Q )...

Fitch Format Proofs - any resources around?...

Formal proof for P → Q ≡ ¬P ∨ Q in Fitch...

Fitch Format Proofs - Any automatic solvers around?...

Deriving Cube(a) from Cube(a) <-> a = a (Fitch)...