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|
(* Refine and let-in's *)
Goal exists x : nat, x = 0.
refine (let y := 0 + 0 in _).
exists y; auto.
Save test1.
Goal exists x : nat, x = 0.
refine (let y := 0 + 0 in ex_intro _ (y + y) _).
auto.
Save test2.
Goal nat.
refine (let y := 0 in 0 + _).
exact 1.
Save test3.
(* Example submitted by Yves on coqdev *)
Require Import List.
Goal forall l : list nat, l = l.
Proof.
refine
(fun l =>
match l return (l = l) with
| nil => _
| O :: l0 => _
| S _ :: l0 => _
end).
Abort.
(* Submitted by Roland Zumkeller (bug #888) *)
(* The Fix and CoFix rules expect a subgoal even for closed components of the
(co-)fixpoint *)
Goal nat -> nat.
refine (fix f (n : nat) : nat := S _
with pred (n : nat) : nat := n
for f).
exact 0.
Qed.
(* Submitted by Roland Zumkeller (bug #889) *)
(* The types of metas were in metamap and they were not updated when
passing through a binder *)
Goal forall n : nat, nat -> n = 0.
refine
(fun n => fix f (i : nat) : n = 0 := match i with
| O => _
| S _ => _
end).
Abort.
(* Submitted by Roland Zumkeller (bug #931) *)
(* Don't turn dependent evar into metas *)
Goal (forall n : nat, n = 0 -> Prop) -> Prop.
intro P.
refine (P _ _).
reflexivity.
Abort.
(* Submitted by Jacek Chrzaszcz (bug #1102) *)
(* le problème a été résolu ici par normalisation des evars présentes
dans les types d'evars, mais le problème reste a priori ouvert dans
le cas plus général d'evars non instanciées dans les types d'autres
evars *)
Goal exists n:nat, n=n.
refine (ex_intro _ _ _).
Abort.
(* Used to failed with error not clean *)
Definition div :
forall x:nat, (forall y:nat, forall n:nat, {q:nat | y = q*n}) ->
forall n:nat, {q:nat | x = q*n}.
refine
(fun m div_rec n =>
match div_rec m n with
| exist _ _ => _
end).
Abort.
(* Use to fail because sigma was not propagated to get_type_of *)
(* Revealed by r9310, fixed in r9359 *)
Goal
forall f : forall a (H:a=a), Prop,
(forall a (H:a = a :> nat), f a H -> True /\ True) ->
True.
intros.
refine (@proj1 _ _ (H 0 _ _)).
Abort.
(* Use to fail because let-in with metas in the body where rejected
because a priori considered as dependent *)
Require Import Peano_dec.
Definition fact_F :
forall (n:nat),
(forall m, m<n -> nat) ->
nat.
refine
(fun n fact_rec =>
if eq_nat_dec n 0 then
1
else
let fn := fact_rec (n-1) _ in
n * fn).
Abort.
(* Wish 1988: that fun forces unfold in refine *)
Goal (forall A : Prop, A -> ~~A).
Proof. refine(fun A a f => _).
|
