... A detailed explanation is available at http://www.frontiernet.net/~mwdaly/recpuzzles/einstein.html. For the record, Einstein didn't write the puzzle and far more than 2% of the world's population could solve it.

As for your approach to solving it, it's certainly possible to permutate all possible combinations, then use perl version of the statements to remove solutions that can't work. However, technicially, I wouldn't call this 'solving' the riddle, since at some point you'd visit all 60^5 possible solutions (I believe that's the right number), and thus this is more like solving an NP problem by just trying every possibility, unlike using some heuristics to pick and choose.

(Now, with rules based programming, it technicially still would have to be solved by the same methods of visiting every solution given the way rules programming is set up, but one can argue that the rules-based system is more efficient since it might find the solution before visiting all solutions.)

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Dr. Michael K. Neylon - mneylon-pm@masemware.com || "You've left the lens cap of your mind on again, Pinky" - The Brain
"I can see my house from here!"
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