Let x0 of type ι be given.
Let x1 of type ι → ο be given.
Let x2 of type ι → ο be given.
Let x3 of type ο be given.
Apply unknownprop_ee0b4b64aba8e6af97035d72b359ab8e1ae1e5e06024c58477c9410cad648356 with
λ x4 x5 : ι → (ι → ο) → (ι → ο) → ο . ((∀ x6 . In x6 x0 ⟶ iff (x1 x6) (x2 x6)) ⟶ x3) ⟶ x5 x0 x1 x2 ⟶ x3.
Assume H0:
(∀ x4 . In x4 x0 ⟶ iff (x1 x4) (x2 x4)) ⟶ x3.
The subproof is completed by applying H0.