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-rw-r--r--theories/Init/Tactics.v100
1 files changed, 96 insertions, 4 deletions
diff --git a/theories/Init/Tactics.v b/theories/Init/Tactics.v
index 5d1e87ae..8df533e7 100644
--- a/theories/Init/Tactics.v
+++ b/theories/Init/Tactics.v
@@ -1,9 +1,11 @@
(************************************************************************)
-(* v * The Coq Proof Assistant / The Coq Development Team *)
-(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016 *)
+(* * The Coq Proof Assistant / The Coq Development Team *)
+(* v * INRIA, CNRS and contributors - Copyright 1999-2018 *)
+(* <O___,, * (see CREDITS file for the list of authors) *)
(* \VV/ **************************************************************)
-(* // * This file is distributed under the terms of the *)
-(* * GNU Lesser General Public License Version 2.1 *)
+(* // * This file is distributed under the terms of the *)
+(* * GNU Lesser General Public License Version 2.1 *)
+(* * (see LICENSE file for the text of the license) *)
(************************************************************************)
Require Import Notations.
@@ -236,3 +238,93 @@ Tactic Notation "clear" "dependent" hyp(h) :=
Tactic Notation "revert" "dependent" hyp(h) :=
generalize dependent h.
+
+(** Provide an error message for dependent induction that reports an import is
+required to use it. Importing Coq.Program.Equality will shadow this notation
+with the actual [dependent induction] tactic. *)
+
+Tactic Notation "dependent" "induction" ident(H) :=
+ fail "To use dependent induction, first [Require Import Coq.Program.Equality.]".
+
+(** *** [inversion_sigma] *)
+(** The built-in [inversion] will frequently leave equalities of
+ dependent pairs. When the first type in the pair is an hProp or
+ otherwise simplifies, [inversion_sigma] is useful; it will replace
+ the equality of pairs with a pair of equalities, one involving a
+ term casted along the other. This might also prove useful for
+ writing a version of [inversion] / [dependent destruction] which
+ does not lose information, i.e., does not turn a goal which is
+ provable into one which requires axiom K / UIP. *)
+
+Ltac simpl_proj_exist_in H :=
+ repeat match type of H with
+ | context G[proj1_sig (exist _ ?x ?p)]
+ => let G' := context G[x] in change G' in H
+ | context G[proj2_sig (exist _ ?x ?p)]
+ => let G' := context G[p] in change G' in H
+ | context G[projT1 (existT _ ?x ?p)]
+ => let G' := context G[x] in change G' in H
+ | context G[projT2 (existT _ ?x ?p)]
+ => let G' := context G[p] in change G' in H
+ | context G[proj3_sig (exist2 _ _ ?x ?p ?q)]
+ => let G' := context G[q] in change G' in H
+ | context G[projT3 (existT2 _ _ ?x ?p ?q)]
+ => let G' := context G[q] in change G' in H
+ | context G[sig_of_sig2 (@exist2 ?A ?P ?Q ?x ?p ?q)]
+ => let G' := context G[@exist A P x p] in change G' in H
+ | context G[sigT_of_sigT2 (@existT2 ?A ?P ?Q ?x ?p ?q)]
+ => let G' := context G[@existT A P x p] in change G' in H
+ end.
+Ltac induction_sigma_in_using H rect :=
+ let H0 := fresh H in
+ let H1 := fresh H in
+ induction H as [H0 H1] using (rect _ _ _ _);
+ simpl_proj_exist_in H0;
+ simpl_proj_exist_in H1.
+Ltac induction_sigma2_in_using H rect :=
+ let H0 := fresh H in
+ let H1 := fresh H in
+ let H2 := fresh H in
+ induction H as [H0 H1 H2] using (rect _ _ _ _ _);
+ simpl_proj_exist_in H0;
+ simpl_proj_exist_in H1;
+ simpl_proj_exist_in H2.
+Ltac inversion_sigma_step :=
+ match goal with
+ | [ H : _ = exist _ _ _ |- _ ]
+ => induction_sigma_in_using H @eq_sig_rect
+ | [ H : _ = existT _ _ _ |- _ ]
+ => induction_sigma_in_using H @eq_sigT_rect
+ | [ H : exist _ _ _ = _ |- _ ]
+ => induction_sigma_in_using H @eq_sig_rect
+ | [ H : existT _ _ _ = _ |- _ ]
+ => induction_sigma_in_using H @eq_sigT_rect
+ | [ H : _ = exist2 _ _ _ _ _ |- _ ]
+ => induction_sigma2_in_using H @eq_sig2_rect
+ | [ H : _ = existT2 _ _ _ _ _ |- _ ]
+ => induction_sigma2_in_using H @eq_sigT2_rect
+ | [ H : exist2 _ _ _ _ _ = _ |- _ ]
+ => induction_sigma_in_using H @eq_sig2_rect
+ | [ H : existT2 _ _ _ _ _ = _ |- _ ]
+ => induction_sigma_in_using H @eq_sigT2_rect
+ end.
+Ltac inversion_sigma := repeat inversion_sigma_step.
+
+(** A version of [time] that works for constrs *)
+
+Ltac time_constr tac :=
+ let eval_early := match goal with _ => restart_timer end in
+ let ret := tac () in
+ let eval_early := match goal with _ => finish_timing ( "Tactic evaluation" ) end in
+ ret.
+
+(** Useful combinators *)
+
+Ltac assert_fails tac :=
+ tryif tac then fail 0 tac "succeeds" else idtac.
+Ltac assert_succeeds tac :=
+ tryif (assert_fails tac) then fail 0 tac "fails" else idtac.
+Tactic Notation "assert_succeeds" tactic3(tac) :=
+ assert_succeeds tac.
+Tactic Notation "assert_fails" tactic3(tac) :=
+ assert_fails tac.