Exercise logic.propositional.consequence

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

Derivation

Final term is not finished

p <-> r, q <-> s => (p /\ q /\ r /\ s) || (~(p /\ q) /\ ~(r /\ s))

⇒ logic.propositional.demorganand, initial=TList [TCon logic1.equivalent [TVar "p",TVar "r"],TCon logic1.equivalent [TVar "q",TVar "s"]]

p <-> r, q <-> s => (p /\ q /\ r /\ s) || ((~p || ~q) /\ ~(r /\ s))

⇒ logic.propositional.demorganand

p <-> r, q <-> s => (p /\ q /\ r /\ s) || ((~p || ~q) /\ (~r || ~s))