NB. written by T.Nishikawa Apr.2012 NB. Usage: NB. * cross 'JAPLA';'APL' NB. ------------------------------------ NB. Primes by Sieve wr =: 1!:2&2 primes =: 3 : 0 N =. 2 + i. <: y PR =. '' i =. 0 while. i < y do. P =. {. N wr PR =. PR, P wr N =. (-. 0 = P|N) # N wr '--------' if. 0 = #N do. goto_fin. end. i =. i + 1 end. label_fin. 'primes = ', ": PR ) NB. cross.ijs NB. cross 'JAPLA';'APL' cross =: 3 : 0 'P Q' =: y PQ0 =: P ="(1 0) Q IPQ0 =: { (i. #Q);(i. #P) IPQ =: (,PQ0) # (,IPQ0) (P ; Q) dis"(1) > IPQ ) NB. ('JAPLA';'APL') dis 1 2 dis =: 3 : 0 : 'I J' =: y 'R S' =: x CR0 =: ((#S), (#R))$' ' CR1 =: S (<(i.#S);J) } CR0 CR2 =: R I } CR1 )