Let x0 of type ι be given.
Let x1 of type ι → ι be given.
Let x2 of type ι → ι be given.
Let x3 of type ι → ι → ο be given.
Apply unknownprop_113414902ba59eae8f7c501c9b2b887a31cba5ee9af5ba8ebd855a250e793fa2 with
942b6.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.