Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι → ι be given.
Assume H0: ∀ x3 . x3 ∈ x0 ⟶ x2 x3 ∈ x1.
Let x3 of type ι be given.
Assume H1:
x3 ∈ prim5 x0 x2.
Apply ReplE_impred with
x0,
x2,
x3,
x3 ∈ x1 leaving 2 subgoals.
The subproof is completed by applying H1.
Let x4 of type ι be given.
Assume H2: x4 ∈ x0.
Assume H3: x3 = x2 x4.
Apply H3 with
λ x5 x6 . x6 ∈ x1.
Apply H0 with
x4.
The subproof is completed by applying H2.