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 1) x1.
The subproof is completed by applying unknownprop_c1205d8a61945e7eb288c6da499403292e9af9500faa25aa1acf052e3d8f0626 with x0, λ x3 . x1, x2.