proposition: Remark R1 : (P->Q)->Q.
proof: Proof. Proof fun H0:P->Q => H0 p. Theorem triple_impl : Q. Proof H R1. End proof_of_triple_impl. Theorem triple_impl_one_liner : (((P->Q)->Q)->Q)->P->Q. Proof. intros H p; apply H; intro H0; apply H0; assumption. Qed.