proposition: Lemma nf_b : forall a b n c, nf (cons a b n c) -> nf b.
proof: Proof. inversion_clear 1;auto. Qed.
imports: EPSILON0 Arith List Omega Compare_dec Relations Wellfounded Max Tools More_nat AccP not_decreasing EPSILON0 More_nat Gamma0_prelude Gamma0_length term rpo