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diff --git a/test-suite/ssr/elim.v b/test-suite/ssr/elim.v new file mode 100644 index 00000000..908249a3 --- /dev/null +++ b/test-suite/ssr/elim.v @@ -0,0 +1,279 @@ +(************************************************************************) +(* * 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 *) +(* * (see LICENSE file for the text of the license) *) +(************************************************************************) + +(* (c) Copyright 2006-2016 Microsoft Corporation and Inria. *) + +Require Import ssreflect. +Require Import ssrbool ssrfun TestSuite.ssr_mini_mathcomp. +Axiom daemon : False. Ltac myadmit := case: daemon. + +(* Ltac debugging feature: recursive elim + eq generation *) +Lemma testL1 : forall A (s : seq A), s = s. +Proof. +move=> A s; elim branch: s => [|x xs _]. +match goal with _ : _ = [::] |- [::] = [::] => move: branch => // | _ => fail end. +match goal with _ : _ = _ :: _ |- _ :: _ = _ :: _ => move: branch => // | _ => fail end. +Qed. + +(* The same but with explicit eliminator and a conflict in the intro pattern *) +Lemma testL2 : forall A (s : seq A), s = s. +Proof. +move=> A s; elim/last_ind branch: s => [|x s _]. +match goal with _ : _ = [::] |- [::] = [::] => move: branch => // | _ => fail end. +match goal with _ : _ = rcons _ _ |- rcons _ _ = rcons _ _ => move: branch => // | _ => fail end. +Qed. + +(* The same but without names for variables involved in the generated eq *) +Lemma testL3 : forall A (s : seq A), s = s. +Proof. +move=> A s; elim branch: s; move: (s) => _. +match goal with _ : _ = [::] |- [::] = [::] => move: branch => // | _ => fail end. +move=> _; match goal with _ : _ = _ :: _ |- _ :: _ = _ :: _ => move: branch => // | _ => fail end. +Qed. + +Inductive foo : Type := K1 : foo | K2 : foo -> foo -> foo | K3 : (nat -> foo) -> foo. + +(* The same but with more intros to be done *) +Lemma testL4 : forall (o : foo), o = o. +Proof. +move=> o; elim branch: o. +match goal with _ : _ = K1 |- K1 = K1 => move: branch => // | _ => fail end. +move=> _; match goal with _ : _ = K2 _ _ |- K2 _ _ = K2 _ _ => move: branch => // | _ => fail end. +move=> _; match goal with _ : _ = K3 _ |- K3 _ = K3 _ => move: branch => // | _ => fail end. +Qed. + +(* Occurrence counting *) +Lemma testO1: forall (b : bool), b = b. +Proof. +move=> b; case: (b) / idP. +match goal with |- is_true b -> true = true => done | _ => fail end. +match goal with |- ~ is_true b -> false = false => done | _ => fail end. +Qed. + +(* The same but only the second occ *) +Lemma testO2: forall (b : bool), b = b. +Proof. +move=> b; case: {2}(b) / idP. +match goal with |- is_true b -> b = true => done | _ => fail end. +match goal with |- ~ is_true b -> b = false => move/(introF idP) => // | _ => fail end. +Qed. + +(* The same but with eq generation *) +Lemma testO3: forall (b : bool), b = b. +Proof. +move=> b; case E: {2}(b) / idP. +match goal with _ : is_true b, _ : b = true |- b = true => move: E => _; done | _ => fail end. +match goal with H : ~ is_true b, _ : b = false |- b = false => move: E => _; move/(introF idP): H => // | _ => fail end. +Qed. + +(* Views *) +Lemma testV1 : forall A (s : seq A), s = s. +Proof. +move=> A s; case/lastP E: {1}s => [| x xs]. +match goal with _ : s = [::] |- [::] = s => symmetry; exact E | _ => fail end. +match goal with _ : s = rcons x xs |- rcons _ _ = s => symmetry; exact E | _ => fail end. +Qed. + +Lemma testV2 : forall A (s : seq A), s = s. +Proof. +move=> A s; case/lastP E: s => [| x xs]. +match goal with _ : s = [::] |- [::] = [::] => done | _ => fail end. +match goal with _ : s = rcons x xs |- rcons _ _ = rcons _ _ => done | _ => fail end. +Qed. + +Lemma testV3 : forall A (s : seq A), s = s. +Proof. +move=> A s; case/lastP: s => [| x xs]. +match goal with |- [::] = [::] => done | _ => fail end. +match goal with |- rcons _ _ = rcons _ _ => done | _ => fail end. +Qed. + +(* Patterns *) +Lemma testP1: forall (x y : nat), (y == x) && (y == x) -> y == x. +move=> x y; elim: {2}(_ == _) / eqP. +match goal with |- (y = x -> is_true ((y == x) && true) -> is_true (y == x)) => move=> -> // | _ => fail end. +match goal with |- (y <> x -> is_true ((y == x) && false) -> is_true (y == x)) => move=> _; rewrite andbC // | _ => fail end. +Qed. + +(* The same but with an implicit pattern *) +Lemma testP2 : forall (x y : nat), (y == x) && (y == x) -> y == x. +move=> x y; elim: {2}_ / eqP. +match goal with |- (y = x -> is_true ((y == x) && true) -> is_true (y == x)) => move=> -> // | _ => fail end. +match goal with |- (y <> x -> is_true ((y == x) && false) -> is_true (y == x)) => move=> _; rewrite andbC // | _ => fail end. +Qed. + +(* The same but with an eq generation switch *) +Lemma testP3 : forall (x y : nat), (y == x) && (y == x) -> y == x. +move=> x y; elim E: {2}_ / eqP. +match goal with _ : y = x |- (is_true ((y == x) && true) -> is_true (y == x)) => rewrite E; reflexivity | _ => fail end. +match goal with _ : y <> x |- (is_true ((y == x) && false) -> is_true (y == x)) => rewrite E => /= H; exact H | _ => fail end. +Qed. + +Inductive spec : nat -> nat -> nat -> Prop := +| specK : forall a b c, a = 0 -> b = 2 -> c = 4 -> spec a b c. +Lemma specP : spec 0 2 4. Proof. by constructor. Qed. + +Lemma testP4 : (1+1) * 4 = 2 + (1+1) + (2 + 2). +Proof. +case: specP => a b c defa defb defc. +match goal with |- (a.+1 + a.+1) * c = b + (a.+1 + a.+1) + (b + b) => subst; done | _ => fail end. +Qed. + +Lemma testP5 : (1+1) * 4 = 2 + (1+1) + (2 + 2). +Proof. +case: (1 + 1) _ / specP => a b c defa defb defc. +match goal with |- b * c = a.+2 + b + (a.+2 + a.+2) => subst; done | _ => fail end. +Qed. + +Lemma testP6 : (1+1) * 4 = 2 + (1+1) + (2 + 2). +Proof. +case: {2}(1 + 1) _ / specP => a b c defa defb defc. +match goal with |- (a.+1 + a.+1) * c = a.+2 + b + (a.+2 + a.+2) => subst; done | _ => fail end. +Qed. + +Lemma testP7 : (1+1) * 4 = 2 + (1+1) + (2 + 2). +Proof. +case: _ (1 + 1) (2 + _) / specP => a b c defa defb defc. +match goal with |- b * a.+4 = c + c => subst; done | _ => fail end. +Qed. + +Lemma testP8 : (1+1) * 4 = 2 + (1+1) + (2 + 2). +Proof. +case E: (1 + 1) (2 + _) / specP=> [a b c defa defb defc]. +match goal with |- b * a.+4 = c + c => subst; done | _ => fail end. +Qed. + +Variables (T : Type) (tr : T -> T). + +Inductive exec (cf0 cf1 : T) : seq T -> Prop := +| exec_step : tr cf0 = cf1 -> exec cf0 cf1 [::] +| exec_star : forall cf2 t, tr cf0 = cf2 -> + exec cf2 cf1 t -> exec cf0 cf1 (cf2 :: t). + +Inductive execr (cf0 cf1 : T) : seq T -> Prop := +| execr_step : tr cf0 = cf1 -> execr cf0 cf1 [::] +| execr_star : forall cf2 t, execr cf0 cf2 t -> + tr cf2 = cf1 -> execr cf0 cf1 (t ++ [:: cf2]). + +Lemma execP : forall cf0 cf1 t, exec cf0 cf1 t <-> execr cf0 cf1 t. +Proof. +move=> cf0 cf1 t; split => [] Ecf. + elim: Ecf. + match goal with |- forall cf2 cf3 : T, tr cf2 = cf3 -> + execr cf2 cf3 [::] => myadmit | _ => fail end. + match goal with |- forall (cf2 cf3 cf4 : T) (t0 : seq T), + tr cf2 = cf4 -> exec cf4 cf3 t0 -> execr cf4 cf3 t0 -> + execr cf2 cf3 (cf4 :: t0) => myadmit | _ => fail end. +elim: Ecf. + match goal with |- forall cf2 : T, + tr cf0 = cf2 -> exec cf0 cf2 [::] => myadmit | _ => fail end. +match goal with |- forall (cf2 cf3 : T) (t0 : seq T), + execr cf0 cf3 t0 -> exec cf0 cf3 t0 -> tr cf3 = cf2 -> + exec cf0 cf2 (t0 ++ [:: cf3]) => myadmit | _ => fail end. +Qed. + +Fixpoint plus (m n : nat) {struct n} : nat := + match n with + | 0 => m + | S p => S (plus m p) + end. + +Definition plus_equation : +forall m n : nat, + plus m n = + match n with + | 0 => m + | p.+1 => (plus m p).+1 + end +:= +fun m n : nat => +match + n as n0 + return + (forall m0 : nat, + plus m0 n0 = + match n0 with + | 0 => m0 + | p.+1 => (plus m0 p).+1 + end) +with +| 0 => @erefl nat +| n0.+1 => fun m0 : nat => erefl (plus m0 n0).+1 +end m. + +Definition plus_rect : +forall (m : nat) (P : nat -> nat -> Type), + (forall n : nat, n = 0 -> P 0 m) -> + (forall n p : nat, + n = p.+1 -> P p (plus m p) -> P p.+1 (plus m p).+1) -> + forall n : nat, P n (plus m n) +:= +fun (m : nat) (P : nat -> nat -> Type) + (f0 : forall n : nat, n = 0 -> P 0 m) + (f : forall n p : nat, + n = p.+1 -> P p (plus m p) -> P p.+1 (plus m p).+1) => +fix plus0 (n : nat) : P n (plus m n) := + eq_rect_r [eta P n] + (let f1 := f0 n in + let f2 := f n in + match + n as n0 + return + (n = n0 -> + (forall p : nat, + n0 = p.+1 -> P p (plus m p) -> P p.+1 (plus m p).+1) -> + (n0 = 0 -> P 0 m) -> + P n0 match n0 with + | 0 => m + | p.+1 => (plus m p).+1 + end) + with + | 0 => + fun (_ : n = 0) + (_ : forall p : nat, + 0 = p.+1 -> + P p (plus m p) -> P p.+1 (plus m p).+1) + (f4 : 0 = 0 -> P 0 m) => unkeyed (f4 (erefl 0)) + | n0.+1 => + fun (_ : n = n0.+1) + (f3 : forall p : nat, + n0.+1 = p.+1 -> + P p (plus m p) -> P p.+1 (plus m p).+1) + (_ : n0.+1 = 0 -> P 0 m) => + let f5 := + let p := n0 in + let H := erefl n0.+1 : n0.+1 = p.+1 in f3 p H in + unkeyed (let Hrec := plus0 n0 in f5 Hrec) + end (erefl n) f2 f1) (plus_equation m n). + +Definition plus_ind := plus_rect. + +Lemma exF x y z: plus (plus x y) z = plus x (plus y z). +elim/plus_ind: z / (plus _ z). +match goal with |- forall n : nat, n = 0 -> plus x y = plus x (plus y 0) => idtac end. +Undo 2. +elim/plus_ind: (plus _ z). +match goal with |- forall n : nat, n = 0 -> plus x y = plus x (plus y 0) => idtac end. +Undo 2. +elim/plus_ind: {z}(plus _ z). +match goal with |- forall n : nat, n = 0 -> plus x y = plus x (plus y 0) => idtac end. +Undo 2. +elim/plus_ind: {z}_. +match goal with |- forall n : nat, n = 0 -> plus x y = plus x (plus y 0) => idtac end. +Undo 2. +elim/plus_ind: z / _. +match goal with |- forall n : nat, n = 0 -> plus x y = plus x (plus y 0) => idtac end. + done. +by move=> _ p _ ->. +Qed. + +(* BUG elim-False *) +Lemma testeF : False -> 1 = 0. +Proof. by elim. Qed. |