(** ** Addition *)
(** Compatibility of addition wrt to order *)
Notation Zplus_le_lt_compat := Z.add_le_lt_mono (only parsing).
Notation Zplus_le_compat := Z.add_le_mono (only parsing).
Notation Zplus_lt_compat := Z.add_lt_mono (only parsing).

Lemma Zplus_le_compat_l n m p : n <= m -> p + n <= p + m.