Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι be given.
Let x3 of type ι be given.
Assume H0:
x3 ∈ setexp x1 x0.
Let x4 of type ι be given.
Assume H1:
x4 ∈ setexp x2 x1.
Apply lam_Pi with
x0,
λ x5 . x2,
λ x5 . ap x4 (ap x3 x5).
Let x5 of type ι be given.
Assume H2: x5 ∈ x0.
Apply ap_Pi with
x1,
λ x6 . x2,
x4,
ap x3 x5 leaving 2 subgoals.
The subproof is completed by applying H1.
Apply ap_Pi with
x0,
λ x6 . x1,
x3,
x5 leaving 2 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H2.