proposition: Lemma prec_antisym : forall s, prec s s -> False.
proof: Proof. destruct s; simpl; trivial. Qed.
imports: Coq(Arith Lia Compare_dec Relations Wellfounded Wf_nat List Bool Eqdep_dec Ensembles ArithRing Logic) hydras(More_Arith Restriction DecPreOrder rpo.term rpo.rpo Epsilon0.T1)