proposition: Lemma is_quotient {G} (X:Torsor G) (y x:X) : ∃! g, g*x = y.
proof: Proof. intros. exact (pr2 (is_torsor_prop X) x 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