Let x0 of type ι be given.
Let x1 of type ι → ι → ο be given.
Assume H0: ∀ x2 x3 . x1 x2 x3 ⟶ x1 x3 x2.
Let x2 of type ι be given.
Let x3 of type ι be given.
Let x4 of type ι be given.
Let x5 of type ι be given.
Let x6 of type ι be given.
Let x7 of type ι be given.
Let x8 of type ι be given.
Assume H3: x6 ⊆ x0.
Assume H4: x7 ⊆ x0.
Assume H5: x8 ⊆ x0.
Assume H9: ∀ x9 . x9 ∈ x6 ⟶ x9 = x5 ⟶ ∀ x10 : ο . x10.
Assume H10:
∀ x9 . x9 ∈ x6 ⟶ nIn x9 x7.
Assume H11:
∀ x9 . x9 ∈ x6 ⟶ nIn x9 x8.
Let x9 of type ι → ι be given.
Assume H15: ∀ x10 . x10 ∈ x6 ⟶ x9 x10 ∈ x7.
Assume H16: ∀ x10 . x10 ∈ x6 ⟶ x1 x10 (x9 x10).
Assume H17:
∀ x10 . x10 ∈ x7 ⟶ ∃ x11 . and (x11 ∈ x6) (x9 x11 = x10).
Let x10 of type ι be given.
Assume H20: x10 ∈ x8.