Let x0 of type ι be given.
Let x1 of type ι be given.
Assume H1:
∀ x2 . x2 ∈ x1 ⟶ ∀ x3 . x3 ∈ x1 ⟶ (x2 = x3 ⟶ ∀ x4 : ο . x4) ⟶ ∃ x4 . and (x4 ∈ ordsucc x0) (x4 ∈ x2 = x4 ∈ x3).
Let x2 of type ο be given.
Assume H3:
∀ x3 : ι → ι . inj x1 (prim4 x0) x3 ⟶ x2.
Apply H3 with
λ x3 . If_i (x0 ∈ x3) (setminus (ordsucc x0) x3) x3.
Apply andI with
∀ x3 . x3 ∈ x1 ⟶ (λ x4 . If_i (x0 ∈ x4) (setminus (ordsucc x0) x4) x4) x3 ∈ prim4 x0,
∀ x3 . x3 ∈ x1 ⟶ ∀ x4 . x4 ∈ x1 ⟶ (λ x5 . If_i (x0 ∈ x5) (setminus (ordsucc x0) x5) x5) x3 = (λ x5 . If_i (x0 ∈ x5) (setminus (ordsucc x0) x5) x5) x4 ⟶ x3 = x4 leaving 2 subgoals.
Let x3 of type ι be given.
Assume H4: x3 ∈ x1.
Apply xm with
x0 ∈ x3,
(λ x4 . If_i (x0 ∈ x4) (setminus (ordsucc x0) x4) x4) x3 ∈ prim4 x0 leaving 2 subgoals.
Assume H5: x0 ∈ x3.
Apply If_i_1 with
x0 ∈ x3,
setminus (ordsucc x0) x3,
x3,
λ x4 x5 . x5 ∈ prim4 x0 leaving 2 subgoals.
The subproof is completed by applying H5.
Apply PowerI with
x0,
setminus (ordsucc x0) x3.
Let x4 of type ι be given.
Apply setminusE with
ordsucc x0,
x3,
x4,
x4 ∈ x0 leaving 2 subgoals.
The subproof is completed by applying H6.
Apply ordsuccE with
x0,
x4,
x4 ∈ x0 leaving 3 subgoals.
The subproof is completed by applying H7.
Assume H9: x4 ∈ x0.
The subproof is completed by applying H9.
Assume H9: x4 = x0.
Apply FalseE with
x4 ∈ x0.
Apply H8.
Apply H9 with
λ x5 x6 . x6 ∈ x3.
The subproof is completed by applying H5.
Apply If_i_0 with
x0 ∈ x3,
setminus (ordsucc x0) x3,
x3,
λ x4 x5 . x5 ∈ prim4 x0 leaving 2 subgoals.
The subproof is completed by applying H5.
Apply PowerI with
x0,
x3.
Let x4 of type ι be given.
Assume H6: x4 ∈ x3.
Apply ordsuccE with
x0,
x4,
x4 ∈ x0 leaving 3 subgoals.
Apply L2 with
x3,
x4 leaving 2 subgoals.
The subproof is completed by applying H4.
The subproof is completed by applying H6.
Assume H7: x4 ∈ x0.
The subproof is completed by applying H7.
Assume H7: x4 = x0.
Apply FalseE with
x4 ∈ x0.
Apply H5.
Apply H7 with
λ x5 x6 . x5 ∈ x3.
The subproof is completed by applying H6.
Let x3 of type ι be given.
Assume H4: x3 ∈ x1.
Let x4 of type ι be given.
Assume H5: x4 ∈ x1.
Apply xm with
x0 ∈ x3,
(λ x5 . If_i (x0 ∈ x5) (setminus (ordsucc x0) x5) x5) x3 = (λ x5 . If_i (x0 ∈ x5) (setminus (ordsucc x0) x5) x5) x4 ⟶ x3 = x4 leaving 2 subgoals.
Assume H6: x0 ∈ x3.
Apply If_i_1 with
...,
...,
...,
... leaving 2 subgoals.