Let x0 of type ι be given.
Let x1 of type ι → ο be given.
Let x2 of type ι → ο be given.
Let x3 of type ι be given.
Apply unknownprop_f9af8d30a6c5e8ee8987f84b6e6030f9a62e2fbfc9ec6ea930e4f0f8e45a5ea5 with
9a89f.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.