Let x0 of type ι be given.
Let x1 of type (ι → ο) → ο be given.
Let x2 of type ι → ο be given.
Let x3 of type ι be given.
Apply unknownprop_e59f089052f5563fc43ad377e6361a6908152b44083942acaade1d7c65627a84 with
c42e1.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.