proposition: Lemma test_pull : forall P Q R : Prop, decidable P -> decidable Q -> (~ True) -> (~ False) -> (~ ~ P) -> (~ (P /\ Q) -> ~ R) -> ((P /\ Q) \/ ~ R) -> (~ (P /\ Q) \/ R) -> (R \/ ~ (P /\ Q)) -> (~ R \/ (P /\ Q)) -> (~ P -> R) -> (~ (R -> P) /\ ~ (Q -> R)) -> (~ P \/ ~ R) -> (P /\ ~ R) -> (~ R /\ P) -> True.
proof: Proof. intros. pull not in *. tauto. Qed.
imports: Decidable Setoid DecidableTypeEx MSetFacts