(* Cf BZ#546 *) Require Import Omega. Section S. Variables n m : nat. Variable H : n Set := | Dummy0 : Dummy 0 | Dummy2 : Dummy 2 | DummyApp : forall i j, Dummy i -> Dummy j -> Dummy (i+j). Definition Bug : Dummy (2*n). Proof. induction n. simpl ; apply Dummy0. replace (2 * S n0) with (2*n0 + 2) ; auto with arith. apply DummyApp. 2:exact Dummy2. apply IHn0 ; abstract omega. Defined. End S.