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 be given.
Apply unknownprop_f69461dac3bae912b172150d7d96a2627a5b3e74180fa1e35bf156c23c40598b with
eb2d9.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.