Re: [Jprogramming] the most impressive & beautiful J phras

[Mike Powell]

Although p: and q: have taken much of the fun out of writing prime  
number algorithms, I've always liked the following for testing for  
whether a number is prime:

[: =/ ] +. >:@i.@<[EMAIL PROTECTED]:
(This also seems to do what you'd expect for negative arguments.)

Mike Powell
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