Exercise logic.propositional.dnf

Description
Proposition to DNF

Derivation

Final term is not finished

~~((q -> r) -> (q || r))

⇒ logic.propositional.defimpl

~~(~(q -> r) || q || r)

⇒ logic.propositional.defimpl

~~(~(~q || r) || q || r)

⇒ logic.propositional.demorganor

~~((~~q /\ ~r) || q || r)

⇒ logic.propositional.notnot

~~((q /\ ~r) || q || r)

⇒ logic.propositional.absorpor

~~(q || r)