foo {
  minus-before-minus: -3;
  minus-after-minus: 3;
  plus-before-minus: -1;
  plus-after-minus: -1;
  not-before-plus: false2;
  not-after-plus: 1false;

  minus-after-comma: 1, -2;
  plus-after-comma: 1, 2;
  slash-after-comma: 1, /2;
  not-after-comma: 1, false;
}