proposition: Theorem Zdivide_Zdiv_eq_2 a b c : 0 < a -> (a | b) -> (c * b) / a = c * (b / a).
proof: Proof. intros. apply Z.divide_div_mul_exact. + now apply Z_lt_neq. + auto with zarith. Qed.
imports: ZArith_base ZArithRing Zcomplements Zdiv Wf_nat