∀ {α : Type u_1} {σ : Type u_4} [inst : Primcodable α] [inst_1 : Primcodable σ] {f : α → ℕ} {g : α → σ}
  {h : α → ℕ × σ → σ},
  Computable f → Computable g → Computable₂ h → Computable fun a => Nat.rec (g a) (fun y IH => h a (y, IH)) (f a)