proposition: Lemma wf_unproj43 : forall (R:binary A3), wf R -> wf (unproj43 A1 A2 A4 R).
proof: Proof. Proof using. intros R H [[[x1 x2] x3] x4]. gen x1 x2 x4. induction_wf IH: H x3. constructor. intros [[[y1 y2] y3] y4]. auto. Qed.
imports: TLC(LibTactics LibLogic LibProd LibSum LibRelation LibNat LibInt)