Module Type ZGcdProp
(Import A : ZAxiomsSig')
(Import B : ZMulOrderProp A)
(Import C : ZSgnAbsProp A B).
Include NZGcdProp A A B.
(** Results concerning divisibility*)

Lemma divide_antisym : forall n m,
(n | m) -> (m | n) -> n == m \/ n == -m.