proposition: Lemma nb_symb_occs_fun : forall f ts, nb_symb_occs (Fun f ts) = 1 + nb_symb_occs_terms ts.
proof: Proof. intros. simpl. rewrite nb_symb_occs_fix. refl. Qed.
imports: CoLoR(ListUtil LogicUtil EqUtil BoolUtil NatUtil VecUtil VecMax ListMax)