proposition: Lemma lt_subterm : forall f ss t, ex (fun s => In s ss /\ (s = t \/ lt t s)) -> lt t (Fun f ss).
proof: Proof. intros f ss t Hex; unfold lt; apply rpo3; trivial. Qed.
imports: CoLoR(VPrecedence MultisetListOrder ListLex VRPO_Type VTerm ListUtil AccUtil LogicUtil) Coq(Relations)