Let x0 of type ι be given.
Let x1 of type ι → ι → ο be given.
Let x2 of type ι → ι → ο be given.
Let x3 of type ι → ο be given.
Apply unknownprop_2f702ddb948250618abc67ca543690804851a488d7643da7c365269893e83b1a with
3bbe6.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.