Let x0 of type ι be given.
Let x1 of type ι → ι be given.
Let x2 of type ι → ι → ο be given.
Let x3 of type ι → ο be given.
Apply unknownprop_050250dc701b1b3b669ada499e4db32c046f36bdb6107aa838249e0b0c968f9e with
81367.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.