Thank you everyone who provided suggestions toward making the rule language more powerful and less tedious. At this point, I will not be adding any more features to the rule language, because I want to keep the rules fixed for the competition. But please feel free to send your ideas, so that we can incorporate them for next year's students.

Also, if you find bugs, please let me know, and I will fix them as soon as possible.

Thanks again,
Your TA

P.S. Hint: if you still find weaknesses in the rule language, and you are feeling ambitious, consider the possibility of writing a program to automatically generate rules.