$a1: 10.0001;
$b1: 10.01;
$c1: -10.0001;
$d1: -10.01;

#foo {
  a: $a1;
  b: $b1;
  c: $c1;
  d: $d1; }

$a2: 0.0001;
$b2: 0.01;
$c2: -0.0001;
$d2: -0.01;

#foo {
  a: $a2;
  b: $b2;
  c: $c2;
  d: $d2; }

$a3: .0001;
$b3: .01;
$c3: -.0001;
$d3: -.01;

#foo {
  a: $a3;
  b: $b3;
  c: $c3;
  d: $d3; }