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 be given.
Apply unknownprop_5e49303ef4a07416d211b5f01b6437c838a15326172047a56f53a4fda3da824e with
e8b89.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.