Let x0 of type ι be given.
Let x1 of type ι → ι be given.
Let x2 of type ι → ι be given.
Let x3 of type ι be given.
Apply unknownprop_1c09d754484ee9ef1fc01eb3279ad46b004886b78702860f3d144e63363865a6 with
5f184.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.