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.
Apply FalseE with
SNoLt x2 (ap x1 x3).
Apply SNoLt_irref with
x2.
Apply H12 with
λ x4 x5 . SNoLt x5 x2.
The subproof is completed by applying H8.