Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type (ι → ο) → ο be given.
Let x3 of type ι → ι be given.
Let x4 of type ι → ι → ο be given.
Let x5 of type ι → ι → ο be given.
Let x6 of type ι be given.
Assume H1: x6 ∈ x1.
Apply H0 with
λ x7 x8 . x3 x6 = ap (ap x8 2) x6.
Apply tuple_5_2_eq with
x1,
encode_c x1 x2,
lam x1 x3,
encode_r x1 x4,
encode_r x1 x5,
λ x7 x8 . x3 x6 = ap x8 x6.
Let x7 of type ι → ι → ο be given.
Apply beta with
x1,
x3,
x6,
λ x8 x9 . x7 x9 x8.
The subproof is completed by applying H1.