Remove reusv5OLD and friends from iset.mm
Remove reusv5OLD and friends from iset.mm

This is reusv5OLD , reusv6OLD , and reusv7OLD .  Although some of
this might be salvageable by changing non-empty to inhabited,
none of them are used in set.mm

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