proposition: Lemma Not_Finite_SomeInf : forall (A:Type)(t: LTree A), ~Finite t -> SomeInf t.
proof: Proof. intro A; cofix the_thm. intro t ; destruct t as [| a t1 t2]. - destruct 1; left. - intro H; case (Not_Finite_or H); [left|right]; apply the_thm ; auto. Qed.
imports: Ltree building graft