Let x0 of type ι be given.
Let x1 of type ι be given.
Assume H3:
∀ x2 . x2 ∈ SNoLev x0 ⟶ iff (x2 ∈ x0) (x2 ∈ x1).
Apply SNoLev_ with
x0,
x0 ⊆ x1 leaving 2 subgoals.
The subproof is completed by applying H0.
Apply SNoLev_ with
x1,
x0 ⊆ x1 leaving 2 subgoals.
The subproof is completed by applying H1.
Let x2 of type ι be given.
Assume H8: x2 ∈ x0.
Apply binunionE with
SNoLev x0,
{(λ x4 . SetAdjoin x4 (Sing 1)) x3|x3 ∈ SNoLev x0},
x2,
x2 ∈ x1 leaving 3 subgoals.
The subproof is completed by applying L9.
Assume H10:
x2 ∈ SNoLev x0.
Apply H3 with
x2,
x2 ∈ x1 leaving 2 subgoals.
The subproof is completed by applying H10.
Assume H11: x2 ∈ x0 ⟶ x2 ∈ x1.
Assume H12: x2 ∈ x1 ⟶ x2 ∈ x0.
Apply H11.
The subproof is completed by applying H8.
Apply ReplE_impred with
SNoLev x0,
λ x3 . (λ x4 . SetAdjoin x4 (Sing 1)) x3,
x2,
x2 ∈ x1 leaving 2 subgoals.
The subproof is completed by applying H10.
Let x3 of type ι be given.
Assume H11:
x3 ∈ SNoLev x0.
Apply exactly1of2_E with
(λ x4 . SetAdjoin x4 (Sing 1)) x3 ∈ x1,
x3 ∈ x1,
x2 ∈ x1 leaving 3 subgoals.
Apply H7 with
x3.
The subproof is completed by applying L13.
Apply H12 with
λ x4 x5 . x5 ∈ x1.
The subproof is completed by applying H14.
Assume H15: x3 ∈ x1.
Apply FalseE with
x2 ∈ x1.
Apply exactly1of2_E with
(λ x4 . SetAdjoin x4 (Sing 1)) x3 ∈ x0,
x3 ∈ x0,
False leaving 3 subgoals.
Apply H5 with
x3.
The subproof is completed by applying H11.
Apply H17.
Apply H3 with
x3,
x3 ∈ x0 leaving 2 subgoals.
The subproof is completed by applying H11.
Assume H18: x3 ∈ x0 ⟶ x3 ∈ x1.
Assume H19: x3 ∈ x1 ⟶ x3 ∈ x0.
Apply H19.
The subproof is completed by applying H15.
Assume H17: x3 ∈ x0.
Apply H16.
Apply H12 with
λ x4 x5 . x4 ∈ x0.
The subproof is completed by applying H8.