{X Y} (f : X -> Y) (H : ismono f) : IsInjective f := fun x0 x1 H' => ap10 (H (Build_HSet Unit) (fun _ => x0) (fun _ => x1) (ap (fun x => unit_name x) H')) tt.
Require Import Basics. Require Import Types.Sigma Types.Paths Types.Unit Types.Arrow.