Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι be given.
Let x3 of type ι be given.
Assume H4: x3 ∈ x1.
Apply H2 with
x3 ∈ x2.
Apply H3 with
x3 ∈ x2.
Apply ordinal_Hered with
x1,
x3 leaving 2 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H4.
Apply exactly1of2_or with
(λ x4 . SetAdjoin x4 (Sing 1)) x3 ∈ x0,
x3 ∈ x0,
x3 ∈ x2 leaving 3 subgoals.
Apply H6 with
x3.
The subproof is completed by applying H4.
Apply H7 with
(λ x4 . SetAdjoin x4 (Sing 1)) x3.
The subproof is completed by applying H10.
Apply binunionE with
x2,
{(λ x5 . SetAdjoin x5 (Sing 1)) x4|x4 ∈ x2},
(λ x4 . SetAdjoin x4 (Sing 1)) x3.
The subproof is completed by applying L11.
Apply L12 with
x3 ∈ x2 leaving 2 subgoals.
Apply FalseE with
x3 ∈ x2.
Apply tagged_notin_ordinal with
x2,
x3 leaving 2 subgoals.
The subproof is completed by applying H1.
The subproof is completed by applying H13.
Apply tagged_ReplE with
x2,
x3 leaving 3 subgoals.
The subproof is completed by applying H1.
The subproof is completed by applying L9.
The subproof is completed by applying H13.
Assume H10: x3 ∈ x0.
Apply H7 with
x3.
The subproof is completed by applying H10.
Claim L12:
or (x3 ∈ x2) (x3 ∈ {(λ x5 . SetAdjoin x5 (Sing 1)) x4|x4 ∈ x2})
Apply binunionE with
x2,
{(λ x5 . SetAdjoin x5 (Sing 1)) x4|x4 ∈ x2},
x3.
The subproof is completed by applying L11.
Apply L12 with
x3 ∈ x2 leaving 2 subgoals.
Assume H13: x3 ∈ x2.
The subproof is completed by applying H13.
Assume H13:
x3 ∈ {(λ x5 . SetAdjoin x5 (Sing 1)) x4|x4 ∈ x2}.
Apply FalseE with
x3 ∈ x2.
Apply ordinal_notin_tagged_Repl with
x3,
x2 leaving 2 subgoals.
The subproof is completed by applying L9.
The subproof is completed by applying H13.