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C00002 00002		However, second order logic (or the use of set theory
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	However, second order logic (or the use of set theory
in first order logic) seems to provide more powerful tools than
any of the above-mentioned formalisms.  It may also handle
possiblility and necessity more pwerfully than modal logic in
some important cases.  The idea is to interpret the statement
that a certain wff is possible as an assertion that predicates
and functions exist satisfying the axioms and for which the given
wff is true.  Up to this point we parallel the previous formalisms
though perhaps with greater explicitness.  Additional power comes
from the fact that 
we don't have to existentially quantify over all predicate
symbols appearing in the wff.