Let x0 of type ι be given.
Let x1 of type ι → ο be given.
Let x2 of type ι be given.
Assume H0:
In x2 (Sep x0 (λ x3 . x1 x3)).
Apply unknownprop_6a6b356f855b99f3fbff4effcb62e3ee6aa23839e10650eb28a503a368c2bb09 with
x0,
x1,
x2,
False.
The subproof is completed by applying H0.