Section QuotientDef.
Variable T : Type.
Record quot_mixin_of qT := QuotClass {
quot_repr : qT -> T;
quot_pi : T -> qT;
_ : cancel quot_repr quot_pi
}.
Notation quot_class_of := quot_mixin_of.
Record quotType := QuotTypePack {
quot_sort :> Type;
quot_class : quot_class_of quot_sort
}.
Variable qT : quotType.
Definition pi_phant of phant qT := quot_pi (quot_class qT).
Local Notation "\pi" := (pi_phant (Phant qT)).
Definition repr_of := quot_repr (quot_class qT).

Lemma repr_ofK : cancel repr_of \pi.