(* (c) Copyright 2006-2015 Microsoft Corporation and Inria. *) (* Distributed under the terms of CeCILL-B. *) Require Import mathcomp.ssreflect.ssreflect. From mathcomp Require Import ssrbool. Axiom daemon : False. Ltac myadmit := case: daemon. Lemma v : True -> bool -> bool. Proof. by []. Qed. Reserved Notation " a -/ b " (at level 0). Reserved Notation " a -// b " (at level 0). Reserved Notation " a -/= b " (at level 0). Reserved Notation " a -//= b " (at level 0). Lemma test : forall a b c, a || b || c. Proof. move=> ---a--- - -/=- -//- -/=- -//=- b [|-]. move: {-}a => /v/v-H; have _ := H I I. Fail move: {-}a {H} => /v-/v-H. have - -> : a = (id a) by []. have --> : a = (id a) by []. have - - _ : a = (id a) by []. have -{1}-> : a = (id a) by []. by myadmit. move: a. case: b => -[] //. by myadmit. Qed.