Let x0 of type ι be given.
Let x1 of type (ι → ο) → ο be given.
Let x2 of type ι → ι be given.
Let x3 of type ι → ι → ο be given.
Apply unknownprop_56550ae67b5306e43e18b43d16689054d82de80302ccba5dd5a7719fafecdafa with
17e9f.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.