Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι be given.
Apply unknownprop_f8cb4609f9c174a593de5a10197e2915f5c1a2d9f32ed8d30c3d30b788bb9e1e with
λ x3 x4 : ι → ι → ι . In x2 (x4 x0 x1) ⟶ In (ap x2 0) x0.
The subproof is completed by applying unknownprop_1196af63ee0683855b52ee91758b2774097fb63c424fb057b925104c7b77f7ef with x0, λ x3 . x1, x2.