Let x0 of type ι be given.
Let x1 of type ι be given.
Assume H1:
x1 ∈ SNoL x0.
Let x2 of type ο be given.
Apply SepE with
SNoS_ (SNoLev x0),
λ x3 . SNoLt x3 x0,
x1,
x2 leaving 2 subgoals.
The subproof is completed by applying H1.
Apply SNoS_E2 with
SNoLev x0,
x1,
x2 leaving 3 subgoals.
Apply SNoLev_ordinal with
x0.
The subproof is completed by applying H0.
The subproof is completed by applying H3.
Apply H2 leaving 3 subgoals.
The subproof is completed by applying H7.
The subproof is completed by applying H5.
The subproof is completed by applying H4.