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.
Let x4 of type ι → ο be given.
Assume H0:
∀ x5 . ∀ x6 x7 : ι → ι → ο . ∀ x8 : ι → ο . x4 (pack_r_r_p x5 x6 x7 x8).
The subproof is completed by applying H0 with x0, x1, x2, x3.