proposition: Lemma cause_ext_cause: forall h l l' h', cause h l l' -> cause (h ++ h') l l'.
proof: Proof. intros. induction H. eapply cause_step_ext_cause_step in H. apply cause_cause_step in H. eassumption. eapply cause_step_ext_cause_step in H0. eapply cause_trans. eassumption. eassumption. Qed.
imports: Coq(FunctionalExtensionality Arith Lia) Coq(Arith.Peano_dec Arith.Compare_dec) Coq(Relations.Relation_Operators) Coq(List) Chapar(Predefs)