The Bactra Review Labyrinths of
Reason
A more precise statement of the case is as follows. If we have a solution, we
can check that it works in polynomial time. So an oracle which always gave us
the right answer, which we just checked out of caution, would solve the problem
in polynomial time: such problems are called ``NP,'' ``non-deterministic
polynomial.'' (``Non-deterministic'' sounds better to computer scientists than
``magical.'') Not having such oracles handy, we have to actually generate the
solution algorithmically, and there are no known algorithms which take less
than exponential time. (There is also no proof that such algorithms don't
exist; whether P=NP is an open problem.)