fact: Definition quotient_functor {A : Type} (R : Relation A) {sR: is_mere_relation _ R} {B : Type} (S : Relation B) {sS: is_mere_relation _ S} (f : A -> B) (fresp : forall x y, R x y -> S (f x) (f y)) : quotient R -> quotient S.
imports: HoTT.Basics HoTT.Types HSet TruncType Truncations.Core