fact: Definition free_abgr_unit {X : hSet} (x : X) : free_abgr X := presented_gr_intro x.
imports: UniMath.MoreFoundations.Subtypes UniMath.MoreFoundations.Sets UniMath.Algebra.Monoids UniMath.Algebra.Groups UniMath.Algebra.IteratedBinaryOperations UniMath.Combinatorics.Lists