fact: Definition is_inverse S (op : CSetoid_bin_op S) Zero x x_inv : Prop := op x x_inv [=] Zero /\ op x_inv x [=] Zero.
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