{T sT} dclass dequiv x y : @F_rec2 T sT dclass dequiv (' x) (' y) = dclass x y := 1. Global Instance F0@{} : Zero F := ('0 : F). Global Instance F1@{} : One F := ('1 : F). Global Instance Fplus@{} : Plus F. Proof. refine (F_rec2 (fun x y => ' (Frac.pl _ x y)) _). intros. apply path. apply Frac.pl_respect;trivial. Defined.
Require Import HoTT.HIT.quotient. Require Import Import Frac.