FUNCTION Main()
   LOCAL r

   /* STEP -1 (downward) */
   r := FrbExec( ;
      'FUNCTION Main()' + Chr(10) + ;
      '   LOCAL i, n := 0' + Chr(10) + ;
      '   FOR i := 5 TO 1 STEP -1' + Chr(10) + ;
      '      n := n + i' + Chr(10) + ;
      '   NEXT' + Chr(10) + ;
      '   RETURN n' + Chr(10) )
   ? "FOR 5 TO 1 STEP -1 sum =", r, "(expect 15)"

   /* STEP 2 (upward by 2) */
   r := FrbExec( ;
      'FUNCTION Main()' + Chr(10) + ;
      '   LOCAL i, n := 0' + Chr(10) + ;
      '   FOR i := 1 TO 10 STEP 2' + Chr(10) + ;
      '      n := n + i' + Chr(10) + ;
      '   NEXT' + Chr(10) + ;
      '   RETURN n' + Chr(10) )
   ? "FOR 1 TO 10 STEP 2 sum =", r, "(expect 25)"

   RETURN NIL