I'm not yet sure where this happens. It may be that a rule includes a regular expression that can match too many ways. The program usually stalls for a long, long time and may eventually run out of memory and crash. Here are example "sentences":
It looks like it might be measurement-3 that is problematic. I see *)+. I think that Marco's algorithm doesn't backtrack, but it must keep tabs on all the possibilities, and maybe there are too many piling up.
I'm not yet sure where this happens. It may be that a rule includes a regular expression that can match too many ways. The program usually stalls for a long, long time and may eventually run out of memory and crash. Here are example "sentences":