Generalize nsuceq0g in iset.mm
Generalize nsuceq0g in iset.mm

As with most theorems which have a set existence hypothesis, make
it A e. V rather than A e. _V . This theorem was only used one
place - peano3 - so simplify the proof of peano3 to use the
revised theorem.

metamath/set.mm,metamath/set.mm,metamath/set.mm