Function: forprime
Section: programming
C-Name: forprime
Prototype: vV=GGI
Help: forprime(X=a,b,seq): the sequence is evaluated, X running over the
 primes between a and b

Function: _diffptr
Class: gp2c_internal
Help: Table of difference of primes.
Description:
 ():bptr        diffptr

Function: _forprime_next
Class: gp2c_internal
Help: Compute the next prime from the diffptr table.
Description:
 (*small,*bptr):void  NEXT_PRIME_VIADIFF($1, $2)

