simp [numeral]
L : Language
hz✝ : Operator.Zero L
ho : Operator.One L
ha : Operator.Add L
z : ℕ
hz : z ≠ 0
⊢ numeral L (z + 1) = op(+).comp ![numeral L z, op(1)]
L : Language
hz✝ : Operator.Zero L
ho : Operator.One L
ha : Operator.Add L
z : ℕ
hz : z ≠ 0
⊢ op(+).foldr op(1) (List.replicate z op(1)) =
    op(+).comp
      ![match z with
        | 0 => op(0)
        | n.succ => op(+).foldr op(1) (List.replicate n op(1)),
        op(1)]