Lemma isunitalfuntoabmonoidfrac (X : abmonoid) (A : submonoid X) : toabmonoidfrac X A 0 = 0. Proof. apply idpath. Defined.
Require Import UniMath.MoreFoundations.Sets. Require Import UniMath.MoreFoundations.Orders. Require Import UniMath.Algebra.Monoids2.