Let x0 of type ι be given.
Let x1 of type ι → ι → ι be given.
Let x2 of type ι → ι → ι be given.
Let x3 of type ι → ι → ο be given.
Let x4 of type ι be given.
Apply unknownprop_21a5e06674fff8cede849d738bc6cb238b5123c757a1617699a596f02614f47d with
a599b.. x0 x1 x2 x3 x4,
x0,
x1,
x2,
x3,
x4.
Let x5 of type ι → ι → ο be given.
The subproof is completed by applying H0.