  The difference between ideal experiments to test Bell's weak nonlocality and
the real experiments leads to loopholes. Ideal experiments involve either
inequalities (Bell) or equalities (Greenberger, Horne, Zeilinger). Every real
experiment has its own critical inequalities, which are almost all more
complicated than the corresponding ideal inequalities and equalities. If one of
these critical inequalities is violated, then the detection loophole is closed,
with no further assumptions. If all the critical inequalities are satisfied,
then it remains open, unless further assumptions are made. The computer program
described here and published on the website
http://www.strings.ph.qmw.ac.uk/QI/main.htm obtains the critical inequalities
for any real experiment, given the number of allowed settings of the angles and
the corresponding possible output signals for a single run. Given all the
necessary conditional probabilities or rates, it tests whether all these
inequalities are satisfied.
