proposition: Lemma quotient_product {G} (X:Torsor G) (z y x:X) : op (z/y) (y/x) = z/x.
proof: Proof. intros. apply quotient_uniqueness. exact (ac_assoc _ _ _ _ @ maponpaths (left_mult (z/y)) (quotient_times y x) @ quotient_times z y). Defined.
imports: UniMath.Foundations.All UniMath.MoreFoundations.Propositions UniMath.MoreFoundations.Notations UniMath.MoreFoundations.Univalence UniMath.MoreFoundations.Tactics UniMath.Algebra.Monoids UniMath.Algebra.Groups UniMath.Combinatorics.OrderedSets