Creates a loop with a custom step.
STEP changes how the counter increments between each loop.
for i to j step k as ?a
i start j finish k step ?a variable
Source for 1 to 10 step 3 as ?i print "i+3 = ?i" nextExecution i+3 = 1 i+3 = 4 i+3 = 7 i+3 = 10