[GAP Forum] a remark on the documentation

[Laurent Bartholdi]

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
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