Let x0 of type ι be given.
Let x1 of type ι be given.
Apply ordinal_Hered with
SNoLev x0,
x1 leaving 2 subgoals.
Apply SNoLev_ordinal with
x0.
The subproof is completed by applying H0.
The subproof is completed by applying H1.
Apply restr_SNo_ with
x0,
x1 leaving 2 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H1.
Apply SNoLev_uniq2 with
x1,
binintersect x0 (SNoElts_ x1) leaving 2 subgoals.
The subproof is completed by applying L2.
The subproof is completed by applying L3.