Library mathcomp.boot.ssrfun

From mathcomp Require Import ssreflect.
From Corelib Require Export ssrfun.
From mathcomp Require Export ssrnotations.
#[export] Set Warnings "-overwriting-delimiting-key".
remove above line when requiring Rocq >= 9.0

Set Implicit Arguments.

v9.1 additions

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

Definition idempotent_op (S : Type) (op : S S S) := x, op x x = x.

#[deprecated(since="mathcomp 2.3.0", note="use `idempotent_op` instead")]
Notation idempotent:= idempotent_op (only parsing).

Definition idempotent_fun (U : Type) (f : U U) := f \o f =1 f.

Lemma inr_inj {A B} : injective (@inr A B).

Lemma inl_inj {A B} : injective (@inl A B).

not yet backported

Lemma taggedK {I : Type} (T_ : I Type) (s : {i : I & T_ i}) :
  Tagged T_ (tagged s) = s.

Definition swap_pair {T1 T2 : Type} (x : T1 × T2) := (x.2, x.1).

Note that this lemma coudn't be an instance of the [involutive] predicate.
Lemma swap_pairK {T1 T2 : Type} : @cancel _ (T1 × T2) swap_pair swap_pair.