Exercise logic.propositional.consequence
Description
Prove that formula is a logical consequence of a set of formulas
Derivation
(p -> (q -> r)) /\ q => p -> r
⇒ logic.propositional.defimpl(~p || (q -> r)) /\ q => p -> r
⇒ logic.propositional.defimpl(~p || ~q || r) /\ q => p -> r
⇒ logic.propositional.defimpl(~p || ~q || r) /\ q => ~p || r
⇒ fakeabsorption(~p || r) /\ q => ~p || r
⇒ conj-elim~p || r => ~p || r