Let x0 of type ι → ι be given.
Let x1 of type ι → ι be given.
Apply unknownprop_1558c688f64494b02af589732af23b540e03110b450c52c9f601b22f3242dd06 with
x0,
x1.
Let x2 of type ι → ι → ο be given.
The subproof is completed by applying H0 with λ x3 x4 . x2 x4 x3.