fact: Definition presented_gr_pr {X : hSet} (R : hrel (free_gr X)) : monoidfun (free_gr X) (presented_gr X R) := monoidquotpr _.
imports: UniMath.MoreFoundations.Subtypes UniMath.MoreFoundations.Sets UniMath.Algebra.Monoids UniMath.Algebra.Groups UniMath.Algebra.IteratedBinaryOperations UniMath.Combinatorics.Lists