proposition: Lemma funApp_subst_funApp : forall M G (MG: correct_subst M G), isFunApp M -> isFunApp (subst MG).
proof: Proof. apply funS_head_subst; trivial. Qed.
imports: CoLoR(RelExtras ListPermutation TermsConv ListUtil ListExtras LogicUtil) Coq(Arith Lia)