Library mathcomp.ssreflect.ssrfun

From mathcomp Require Import ssreflect.
From Coq Require Export ssrfun.
From mathcomp Require Export ssrnotations.
#[export] Set Warnings "-overwriting-delimiting-key".
because there is some Set Warnings "overwriting-delimiting-key". somewhere in the above v8.17 additions oflit f := Some \o f

Set Implicit Arguments.

Definition olift aT rT (f : aT rT) := Some \o f.

Lemma obindEapp {aT rT} (f : aT option rT) : obind f = oapp f None.

Lemma omapEbind {aT rT} (f : aT rT) : omap f = obind (olift f).

Lemma omapEapp {aT rT} (f : aT rT) : omap f = oapp (olift f) None.

Lemma oappEmap {aT rT} (f : aT rT) (y0 : rT) x :
  oapp f y0 x = odflt y0 (omap f x).

Lemma omap_comp aT rT sT (f : aT rT) (g : rT sT) :
  omap (g \o f) =1 omap g \o omap f.

Lemma oapp_comp aT rT sT (f : aT rT) (g : rT sT) x :
  oapp (g \o f) x =1 (@oapp _ _)^~ x g \o omap f.

Lemma oapp_comp_f {aT rT sT} (f : aT rT) (g : rT sT) (x : rT) :
  oapp (g \o f) (g x) =1 g \o oapp f x.

Lemma olift_comp aT rT sT (f : aT rT) (g : rT sT) :
  olift (g \o f) = olift g \o f.

Lemma compA {A B C D : Type} (f : B A) (g : C B) (h : D C) :
  f \o (g \o h) = (f \o g) \o h.

Lemma ocan_comp [A B C : Type] [f : B option A] [h : C option B]
    [f' : A B] [h' : B C] :
  ocancel f f' ocancel h h' ocancel (obind f \o h) (h' \o f').

v8.18 additions

Notation sval := (@proj1_sig _ _).

v8.20 additions The notations below are already defined in Coq.ssr.ssrfun, but we redefine them in different notation scopes (mostly fun_scope -> function_scope, in order to replace the former with the latter).

Open Scope function_scope.

Notation "f ^~ y" := (fun xf x y) : function_scope.
Notation "@^~ x" := (fun ff x) : function_scope.

Notation "[ 'fun' : T => E ]" := (SimplFun (fun _ : TE)) : function_scope.
Notation "[ 'fun' x => E ]" := (SimplFun (fun xE)) : function_scope.
Notation "[ 'fun' x y => E ]" := (fun x[fun y E]) : function_scope.
Notation "[ 'fun' x : T => E ]" := (SimplFun (fun x : TE))
  (only parsing) : function_scope.
Notation "[ 'fun' x y : T => E ]" := (fun x : T[fun y : T E])
  (only parsing) : function_scope.
Notation "[ 'fun' ( x : T ) y => E ]" := (fun x : T[fun y E])
  (only parsing) : function_scope.
Notation "[ 'fun' x ( y : T ) => E ]" := (fun x[fun y : T E])
  (only parsing) : function_scope.
Notation "[ 'fun' ( x : T ) ( y : U ) => E ]" := (fun x : T[fun y : U E])
  (only parsing) : function_scope.

Notation "f1 =1 f2" := (eqfun f1 f2) : type_scope.
Notation "f1 =1 f2 :> A" := (f1 =1 (f2 : A)) : type_scope.
Notation "f1 =2 f2" := (eqrel f1 f2) : type_scope.
Notation "f1 =2 f2 :> A" := (f1 =2 (f2 : A)) : type_scope.

Notation "f1 \o f2" := (comp f1 f2) : function_scope.
Notation "f1 \; f2" := (catcomp f1 f2) : function_scope.

Notation "[ 'eta' f ]" := (fun xf x) : function_scope.

Notation "'fun' => E" := (fun _E) : function_scope.

Notation "@ 'id' T" := (fun x : Tx)
  (at level 10, T at level 8, only parsing) : function_scope.

Notation "@ 'sval'" := (@proj1_sig) (at level 10, only parsing) :
  function_scope.

not yet backported

#[export] Set Warnings "-hiding-delimiting-key".
Delimit Scope function_scope with FUN.
Close Scope fun_scope.

Definition injective2 (rT aT1 aT2 : Type) (f : aT1 aT2 rT) :=
   (x1 x2 : aT1) (y1 y2 : aT2), f x1 y1 = f x2 y2 (x1 = x2) × (y1 = y2).

Arguments injective2 [rT aT1 aT2] f.

Lemma inj_omap {aT rT : Type} (f : aT rT) :
  injective f injective (omap f).

Lemma omap_id {T : Type} (x : option T) : omap id x = x.

Lemma eq_omap {aT rT : Type} (f g : aT rT) : f =1 g omap f =1 omap g.

Lemma omapK {aT rT : Type} (f : aT rT) (g : rT aT) :
  cancel f g cancel (omap f) (omap g).