loop-scope {
  forward--1: 1 1;
  forward--2: 2 2;
  forward--3: 3 3;
  forward--4: 4 4;
  forward--5: 5 5;
  forward--6: 6 6;
  forward--7: 7 7;
  forward--8: 8 8;
  forward--9: 9 9;
  backward-1: 1 1;
  backward-2: 2 2;
  backward-3: 3 3;
  backward-4: 4 4;
  backward-5: 5 5;
  backward-6: 6 6;
  backward-7: 7 7;
  backward-8: 8 8;
  backward-9: 9 9;
}