Let x0 of type ι be given.
Let x1 of type ι → ι be given.
Let x2 of type ι → ι → ο be given.
Apply unknownprop_ff14fe4b2b5ebb9a364ac3d2b72652c556f881650361e9e04e15eb4f78727558 with
73737.. x0 x1 x2,
x0,
x1,
x2.
Let x3 of type ι → ι → ο be given.
The subproof is completed by applying H0.