There are many considerations that go into developing a computer program
which runs for months and years. Interruptions, ranging from power
failures to hardware maintenance, are to be expected. A program should not
have to restart from the very beginning for every interruption; otherwise,
it may never finish. To solve the restarting problem, we partitioned our
starting configurations into smaller cases and a message was output onto a
log file every time one of them was finished. If there was an
interruption, we just looked up the last completed case and continued from
that point. For our programs, a convenient subdivision was at the ``A2''
boundary; more details can be found in [19,21]. The messages
written on the log file also contained statistics about the run to allow
comparison and verification of the results.