dear group, i just crossed the following in 'programming tutorial', 2.6-1 ---------------------- Another example would be the implementation of the conclusion that every finite group of prime power order is nilpotent. This could be done by installing an immediate method for the attribute IsNilpotentGroup with requirement IsGroup and Tester( Size ). This method would then check whether the size is a finite prime power, return true in this case and otherwise call TryNextMethod (2.4-1). But this requires factoring of an integer, which cannot be guaranteed to be very cheap, so one should not install this method as an immediate method. ---------------------- this strikes me as strange: one doesn't have to factor the order, one just must check whether it's a proper power, and if not whether it's prime. both tests are polynomial in number of digits, and probably blindingly fast for all groups that GAP can handle. therefore 1) i think the example in the documentation is a bit confusing; 2) this method should be implemented if it's not there already.
best, laurent -- Laurent Bartholdi \ laurent.bartholdi<at>gmail<dot>com EPFL SB SMA IMB MAD \ Téléphone: +41 21-6935458 Station 8 \ Secrétaire: +41 21-6935471 CH-1015 Lausanne, Switzerland \ Fax: +41 21-6930339 _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
