proposition: Lemma plus_ge_compat : forall m n m' n', m >>= m' -> n >>= n' -> m + n >>= m' + n'.
proof: Proof. intros. destruct m; destruct n; destruct m'; destruct n'; simpl; trivial; arctic_ord. apply Zmax_ge_compat; hyp. apply Z.le_ge. apply elim_Zmax_l. lia. apply Z.le_ge. apply elim_Zmax_r. lia. Qed.
imports: Coq(Morphisms) CoLoR(RelDec RelUtil SN RelExtras NatUtil LogicUtil ZUtil)