proposition: Lemma mul_div_undo: forall i c, c <> 0 -> c * i / c = i.
proof: Proof. intros. pose proof (Nat.div_mul_cancel_l i 1 c) as P. rewrite Nat.div_1_r in P. rewrite Nat.mul_1_r in P. apply P; auto. Qed.
imports: Coq.Classes.Morphisms Coq.Classes.Morphisms_Prop Coq.Bool.Bool Coq.Arith.Arith Coq.micromega.Lia Coq.NArith.NArith Coq.ZArith.ZArith bbv.N_Z_nat_conversions bbv.Nomega