proposition: Lemma wf_prod4_of_wf_3 : forall (A1 A2 A3 A4:Type) (R1:binary A1) (R2:binary A2) (R3:binary A3) (R4:binary A4), wf R3 -> wf (prod4 R1 R2 R3 R4).
proof: Proof. Proof using. intros. apply wf_prod2_of_wf_1. apply~ wf_prod3_of_wf_3. Qed.
imports: TLC(LibTactics LibLogic LibProd LibSum LibRelation LibNat LibInt)