Library Coq.ssr.ssreflect

Require Import Bool. Require Import ssrmatching.


Set Implicit Arguments.

Module SsrSyntax.


Reserved Notation "(* x 'is' y 'of' z 'isn't' // /= //= *)" (at level 8).
Reserved Notation "(* 69 *)" (at level 69).

Reserved Notation "(* Use to test if 'SsrSyntax_is_Imported' *)" (at level 8).

Reserved Notation "<hidden n >" (at level 200).
Reserved Notation "T (* n *)" (at level 200, format "T (* n *)").

End SsrSyntax.

Export SsrMatchingSyntax.
Export SsrSyntax.


Delimit Scope general_if_scope with GEN_IF.

Notation "'if' c 'then' v1 'else' v2" :=
  (if c then v1 else v2)
  (at level 200, c, v1, v2 at level 200, only parsing) : general_if_scope.

Notation "'if' c 'return' t 'then' v1 'else' v2" :=
  (if c return t then v1 else v2)
  (at level 200, c, t, v1, v2 at level 200, only parsing) : general_if_scope.

Notation "'if' c 'as' x 'return' t 'then' v1 'else' v2" :=
  (if c as x return t then v1 else v2)
  (at level 200, c, t, v1, v2 at level 200, x ident, only parsing)
     : general_if_scope.


Delimit Scope boolean_if_scope with BOOL_IF.

Notation "'if' c 'return' t 'then' v1 'else' v2" :=
  (if c%bool is true in bool return t then v1 else v2) : boolean_if_scope.

Notation "'if' c 'then' v1 'else' v2" :=
  (if c%bool is true in bool return _ then v1 else v2) : boolean_if_scope.

Notation "'if' c 'as' x 'return' t 'then' v1 'else' v2" :=
  (if c%bool is true as x in bool return t then v1 else v2) : boolean_if_scope.

Open Scope boolean_if_scope.

Delimit Scope form_scope with FORM.
Open Scope form_scope.

Notation "x : T" := (x : T)
  (at level 100, right associativity,
   format "'[hv' x '/ ' : T ']'") : core_scope.

Notation "T : 'Type'" := (T%type : Type)
  (at level 100, only parsing) : core_scope.
Notation "P : 'Prop'" := (P%type : Prop)
  (at level 100, only parsing) : core_scope.

Definition abstract_lock := unit.
Definition abstract_key := tt.

Definition abstract (statement : Type) (id : nat) (lock : abstract_lock) :=
  let: tt := lock in statement.

Notation "<hidden n >" := (abstract _ n _).
Notation "T (* n *)" := (abstract T n abstract_key).

Inductive external_view : Type := tactic_view of Type.


Module TheCanonical.

CoInductive put vT sT (v1 v2 : vT) (s : sT) := Put.

Definition get vT sT v s (p : @put vT sT v v s) := let: Put _ _ _ := p in s.

Definition get_by vT sT of sT -> vT := @get vT sT.

End TheCanonical.

Import TheCanonical.

Notation "[ 'the' sT 'of' v 'by' f ]" :=
  (@get_by _ sT f _ _ ((fun v' (s : sT) => Put v' (f s) s) v _))
  (at level 0, only parsing) : form_scope.

Notation "[ 'the' sT 'of' v ]" := (get ((fun s : sT => Put v s s) _))
  (at level 0, only parsing) : form_scope.


Notation "[ 'th' 'e' sT 'of' v 'by' f ]" := (@get_by _ sT f v _ _)
  (at level 0, format "[ 'th' 'e' sT 'of' v 'by' f ]") : form_scope.

Notation "[ 'th' 'e' sT 'of' v ]" := (@get _ sT v _ _)
  (at level 0, format "[ 'th' 'e' sT 'of' v ]") : form_scope.



Definition argumentType T P & forall x : T, P x := T.
Definition dependentReturnType T P & forall x : T, P x := P.
Definition returnType aT rT & aT -> rT := rT.

Notation "{ 'type' 'of' c 'for' s }" := (dependentReturnType c s)
  (at level 0, format "{ 'type' 'of' c 'for' s }") : type_scope.


CoInductive phantom T (p : T) := Phantom.
CoInductive phant (p : Type) := Phant.


Definition protect_term (A : Type) (x : A) : A := x.


Notation unkeyed x := (let flex := x in flex).

Definition ssr_converse R (r : R) := (Logic.I, r).
Notation "=^~ r" := (ssr_converse r) (at level 100) : form_scope.


Notation nosimpl t := (let: tt := tt in t).

Lemma master_key : unit.
Definition locked A := let: tt := master_key in fun x : A => x.

Lemma lock A x : x = locked x :> A.

Lemma not_locked_false_eq_true : locked false <> true.

Ltac done :=
  trivial; hnf; intros; solve
   [ do ![solve [trivial | apply: sym_equal; trivial]
         | discriminate | contradiction | split]
   | case not_locked_false_eq_true; assumption
   | match goal with H : ~ _ |- _ => solve [case H; trivial] end ].

Ltac ssrdone0 :=
  trivial; hnf; intros; solve
   [ do ![solve [trivial | apply: sym_equal; trivial]
         | discriminate | contradiction ]
   | case not_locked_false_eq_true; assumption
   | match goal with H : ~ _ |- _ => solve [case H; trivial] end ].

Structure unlockable T v := Unlockable {unlocked : T; _ : unlocked = v}.
Lemma unlock T x C : @unlocked T x C = x.

Notation "[ 'unlockable' 'of' C ]" := (@Unlockable _ _ C (unlock _))
  (at level 0, format "[ 'unlockable' 'of' C ]") : form_scope.

Notation "[ 'unlockable' 'fun' C ]" := (@Unlockable _ (fun _ => _) C (unlock _))
  (at level 0, format "[ 'unlockable' 'fun' C ]") : form_scope.


Definition locked_with k := let: tt := k in fun T x => x : T.

Lemma locked_withE T k x : unkeyed (locked_with k x) = x :> T.

Canonical locked_with_unlockable T k x :=
  @Unlockable T x (locked_with k x) (locked_withE k x).

Lemma unlock_with T k x : unlocked (locked_with_unlockable k x) = x :> T.


Definition ssr_have Plemma Pgoal (step : Plemma) rest : Pgoal := rest step.

Definition ssr_have_let Pgoal Plemma step
  (rest : let x : Plemma := step in Pgoal) : Pgoal := rest.

Definition ssr_suff Plemma Pgoal step (rest : Plemma) : Pgoal := step rest.

Definition ssr_wlog := ssr_suff.


Fixpoint nary_congruence_statement (n : nat)
         : (forall B, (B -> B -> Prop) -> Prop) -> Prop :=
  match n with
  | O => fun k => forall B, k B (fun x1 x2 : B => x1 = x2)
  | S n' =>
    let k' A B e (f1 f2 : A -> B) :=
      forall x1 x2, x1 = x2 -> (e (f1 x1) (f2 x2) : Prop) in
    fun k => forall A, nary_congruence_statement n' (fun B e => k _ (k' A B e))
  end.

Lemma nary_congruence n (k := fun B e => forall y : B, (e y y : Prop)) :
  nary_congruence_statement n k.

Lemma ssr_congr_arrow Plemma Pgoal : Plemma = Pgoal -> Plemma -> Pgoal.


Section ApplyIff.

Variables P Q : Prop.
Hypothesis eqPQ : P <-> Q.

Lemma iffLR : P -> Q.
Lemma iffRL : Q -> P.

Lemma iffLRn : ~P -> ~Q.
Lemma iffRLn : ~Q -> ~P.

End ApplyIff.


Lemma abstract_context T (P : T -> Type) x :
  (forall Q, Q = P -> Q x) -> P x.