Get rid of OLD theorems in iset.mm
Get rid of OLD theorems in iset.mm

These are propositional logic and predicate logic theorems
which are unused.

The list is anidmOLD , pm4.24OLD , mpanr2OLD , pm3.43OLD ,
orabsOLD , mpbir3anOLD , mpbir3andOLD , alrot4OLD , and equidqeOLD

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