Let x0 of type ι be given.
Let x1 of type ι be given.
Apply SNoS_E2 with
ordsucc x0,
x1,
∃ x2 . and (x2 ∈ x0) (x1 = eps_ x2) leaving 3 subgoals.
Apply nat_p_ordinal with
ordsucc x0.
Apply nat_ordsucc with
x0.
The subproof is completed by applying H0.
The subproof is completed by applying H1.
Apply nat_inv with
SNoLev x1,
∃ x2 . and (x2 ∈ x0) (x1 = eps_ x2) leaving 3 subgoals.
The subproof is completed by applying L8.
Apply FalseE with
∃ x2 . and (x2 ∈ x0) (x1 = eps_ x2).
Claim L10: x1 = 0
Apply SNoLev_0_eq_0 with
x1 leaving 2 subgoals.
The subproof is completed by applying H6.
The subproof is completed by applying H9.
Apply SNoLt_irref with
x1.
Apply L10 with
λ x2 x3 . SNoLt x3 x1.
The subproof is completed by applying H2.
Apply H9 with
∃ x2 . and (x2 ∈ x0) (x1 = eps_ x2).
Let x2 of type ι be given.
Apply H10 with
∃ x3 . and (x3 ∈ x0) (x1 = eps_ x3).
Let x3 of type ο be given.
Assume H13:
∀ x4 . and (x4 ∈ x0) (x1 = eps_ x4) ⟶ x3.
Apply H13 with
x2.
Apply andI with
x2 ∈ x0,
x1 = eps_ x2 leaving 2 subgoals.
Apply nat_ordsucc_trans with
x0,
SNoLev x1,
x2 leaving 3 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H4.
Apply H12 with
λ x4 x5 . x2 ∈ x5.
The subproof is completed by applying ordsuccI2 with x2.
Apply SNo_eq with
x1,
eps_ x2 leaving 4 subgoals.
The subproof is completed by applying H6.
Apply SNo_eps_ with
x2.
Apply nat_p_omega with
x2.
The subproof is completed by applying H11.
Apply SNoLev_eps_ with
x2,
λ x4 x5 . SNoLev x1 = x5 leaving 2 subgoals.
Apply nat_p_omega with
x2.
The subproof is completed by applying H11.
The subproof is completed by applying H12.
Apply SNoEq_tra_ with
SNoLev x1,
x1,
eps_ x0,
eps_ x2 leaving 2 subgoals.
Apply SNoEq_sym_ with
SNoLev x1,
eps_ x0,
x1.
The subproof is completed by applying H3.
Apply H12 with
λ x4 x5 . SNoEq_ x5 (eps_ x0) (eps_ x2).
Apply SNoEq_I with
ordsucc x2,
eps_ x0,
eps_ x2.
Let x4 of type ι be given.
Apply nat_p_ordinal with
x4.
Apply nat_p_trans with
ordsucc x2,
x4 leaving 2 subgoals.
Apply nat_ordsucc with
x2.
The subproof is completed by applying H11.
The subproof is completed by applying H14.
Apply iffI with
x4 ∈ eps_ x0,
x4 ∈ eps_ x2 leaving 2 subgoals.
Assume H16:
x4 ∈ eps_ x0.
Apply eps_ordinal_In_eq_0 with
x0,
x4,
λ x5 x6 . x6 ∈ eps_ x2 leaving 3 subgoals.
The subproof is completed by applying L15.
The subproof is completed by applying H16.
Apply binunionI1 with
Sing 0,
{SetAdjoin (ordsucc x5) (Sing 1)|x5 ∈ x2},
0.
The subproof is completed by applying SingI with 0.
Assume H16:
x4 ∈ eps_ x2.
Apply eps_ordinal_In_eq_0 with
x2,
x4,
λ x5 x6 . x6 ∈ eps_ x0 leaving 3 subgoals.
The subproof is completed by applying L15.
The subproof is completed by applying H16.
Apply binunionI1 with
Sing 0,
{SetAdjoin (ordsucc x5) (Sing 1)|x5 ∈ x0},
0.
The subproof is completed by applying SingI with 0.