-theorem nle_gen_succ_1: \forall x,y. x < y \to
- \exists z. y = succ z \land x <= z.
- unfold NLE.
- intros. decompose.
- lapply linear nplus_gen_succ_2 to H1 as H.
- decompose. subst.
- apply ex_intro; auto. (**)
+theorem nle_inv_succ_1: \forall x,y. x < y \to
+ \exists z. y = succ z \land x <= z.
+ intros. elim H.
+ lapply linear nplus_gen_succ_2 to H1.
+ decompose. subst. auto depth = 4.