proposition: Theorem convol_mul_0_l : ∀ a i, (convol_mul 0%ser a i = 0)%K.
proof: Proof. intros a k. unfold convol_mul. apply all_0_summation_0; intros i Hi. rewrite series_nth_series_0. rewrite rng_mul_0_l; reflexivity. Qed.
imports: Utf8 QArith NPeano Misc NbarM Field2 Fsummation