prod,sum := 1,0;  /* start with a product of unity, sum of 0 */
x,y,z := 5, -5, -2;
one,three,seven := 1,3,7;
foreach j in (Walker.chain([-three..(3).pow(3),three], // do these sequentially
               [-seven..seven,x], [555..550 - y], [22..-28,-three], #[start..last,step]
               [1927..1939], [x..y,z], [(11).pow(x)..(11).pow(x) + one])){
   sum+=j.abs();	/* add absolute value of J */
   if(prod.abs()<(2).pow(27) and j!=0) prod*=j; /* PROD is small enough & J */
}
/* SUM and PROD are used for verification of J incrementation */
println("sum  = %,d\nprod = %,d".fmt(sum,prod));