fact: Definition free_monoid_as_CMonoid:CMonoid:= (Build_CMonoid (Astar_as_CSemiGroup A)(empty_word A) free_monoid_is_CMonoid).
imports: Coq.Arith.Euclid CoRN.model.Zmod.Cmod CoRN.algebra.CSemiGroups CoRN.tactics.csetoid_rewrite CoRN.model.structures.Nsec CoRN.util.SetoidPermutation Coq.Setoids.Setoid Coq.Classes.Morphisms