Let x0 of type ι → (ι → ι) → ο be given.
Assume H0: ∀ x1 . ∀ x2 : ι → ι . (∀ x3 . x3 ∈ x1 ⟶ x2 x3 ∈ x1) ⟶ ∀ x3 : ι → ι . (∀ x4 . x4 ∈ x1 ⟶ x2 x4 = x3 x4) ⟶ x0 x1 x3 = x0 x1 x2.
Assume H1: x0 1 (λ x1 . 0).
Assume H2:
x0 omega (λ x1 . x1).