Let x0 of type ι be given.
Let x1 of type ι → ι be given.
Let x2 of type ι → ι be given.
Assume H0: ∀ x3 . x3 ∈ x0 ⟶ x1 x3 = x2 x3.
Let x3 of type ι be given.
Assume H1: x3 ∈ {x1 x4|x4 ∈ x0}.
Apply ReplE_impred with
x0,
x1,
x3,
x3 ∈ prim5 x0 x2 leaving 2 subgoals.
The subproof is completed by applying H1.
Let x4 of type ι be given.
Assume H2: x4 ∈ x0.
Assume H3: x3 = x1 x4.
Apply H3 with
λ x5 x6 . x6 ∈ {x2 x7|x7 ∈ x0}.
Apply H0 with
x4,
λ x5 x6 . x6 ∈ {x2 x7|x7 ∈ x0} leaving 2 subgoals.
The subproof is completed by applying H2.
Apply ReplI with
x0,
x2,
x4.
The subproof is completed by applying H2.