Exercise logic.propositional.consequence

Description
Prove that formula is a logical consequence of a set of formulas

Derivation

Final term is not finished

~q => (p || (~(p || q) /\ ~p) || q) /\ (p || (~(p || q) /\ ~p))

⇒ logic.propositional.demorganor, initial=TList [TCon logic1.not [TVar "q"]]

~q => (p || (~p /\ ~q /\ ~p) || q) /\ (p || (~(p || q) /\ ~p))

⇒ absorpand-subset

~q => (p || (~p /\ ~q) || q) /\ (p || (~(p || q) /\ ~p))