Let x0 of type ι be given.
Let x1 of type ι → ι → ο be given.
Let x2 of type ι be given.
Let x3 of type ι → ι → ο be given.
set y4 to be ...
Let x5 of type ι → ο be given.
set y6 to be ...
Apply unpack_r_i_eq with
(λ x7 . λ x8 : ι → ι → ο . λ x9 . λ x10 : ι → ι → ο . unpack_r_i (pack_r x7 x8) ((λ x11 . λ x12 : ι → ι → ο . λ x13 . λ x14 : ι → ι → ο . pack_r (setsum x11 x13) (λ x15 x16 . or (and (and (x15 = Inj0 (Unj x15)) (x16 = Inj0 (Unj x16))) (x12 (Unj x15) (Unj x16))) (and (and (x15 = Inj1 (Unj x15)) (x16 = Inj1 (Unj x16))) (x14 (Unj x15) (Unj x16))))) x9 x10)) x3 y4,
x1,
y6,
λ x7 . y6 leaving 2 subgoals.
Let x7 of type ι → ι → ο be given.
Assume H2:
∀ x8 . x8 ∈ x1 ⟶ ∀ x9 . x9 ∈ x1 ⟶ iff (y6 x8 x9) (x7 x8 x9).
Let x5 of type ι → ι → ο be given.
Apply L1 with
λ x6 . x5 x6 y4 ⟶ x5 y4 x6.
Assume H2: x5 y4 y4.
The subproof is completed by applying H2.