Exercise logic.propositional.dnf

Description
Proposition to DNF

Derivation

F || q || r || ~(q -> r)
logic.propositional.defimpl
F || q || r || ~(~q || r)
logic.propositional.demorganor
F || q || r || (~~q /\ ~r)
logic.propositional.notnot
F || q || r || (q /\ ~r)