P31

(de is-prime (N)
   (or
      (= N 2)
      (and
         (> N 1)
         (bit? 1 N)
         (for (D 3  T  (+ D 2))
            (T (> D (sqrt N)) T)
            (T (=0 (% N D)) NIL) ) ) ) )

http://picolisp.com/wiki/?99p31

10jul10

abu