Let x0 of type ι be given.
Let x1 of type (ι → ο) → ο be given.
Let x2 of type ι → ι → ι be given.
Let x3 of type ι → ι be given.
Apply unknownprop_921117f7b60df499ef56a35fd6f233c15a67ebfa690798afac8bf627a076c556 with
21805.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.