@a: 2; @x: (@a * @a); @y: (@x + 1); @z: (@x * 2 + @y); @var: -1;

.variables {

width: (@z + 1cm); // 14cm

}

@b: @a * 10; @c: #888;

@fonts: “Trebuchet MS”, Verdana, sans-serif; @f: @fonts;

@quotes: “~” “~”; @q: @quotes; @onePixel: 1px;

.variables {

height: (@b + @x + 0px); // 24px
color: @c;
font-family: @f;
quotes: @q;

}

.redef {

@var: 0;
.inition {
    @var: 4;
    @var: 2;
    three: @var;
    @var: 3;
}
zero: @var;

}

@important-var: @c !important; @important-var-two: @a !important; .values {

minus-one: @var;
@a: 'Trebuchet';
@multi: 'A', B, C;
font-family: @a, @a, @a;
color: @c !important;
same-color: @important-var;
same-again: @important-var !important;
multi-important: @important-var @important-var, @important-var-two;
multi: something @multi, @a;

}

.variable-names {

.quoted {
    @var: 'hello';
    @name: 'var';
    name: @@name;
}

.unquoted {
    @var: 'hello';
    @name: var;
    name: @@name;
}

.color-keyword {
    @red: 'hello';
    @name: red;
    name: @@name;
}

}

.alpha {

@var: 42;
filter: alpha(opacity=@var);

}

.polluteMixin() {

@a: 'pollution';

} .testPollution {

@a: 'no-pollution';
a: @a;
.polluteMixin();
a: @a;

}

.units {

width: @onePixel;
same-unit-as-previously: (@onePixel / @onePixel);
square-pixel-divided: (@onePixel * @onePixel / @onePixel);
odd-unit: unit((@onePixel * 4em / 2cm));
percentage: (10 * 50%);
pixels: (50px * 10);
conversion-metric-a: (20mm + 1cm);
conversion-metric-b: (1cm + 20mm);
conversion-imperial: (1in + 72pt + 6pc);
custom-unit: (42octocats * 10);
custom-unit-cancelling: (8cats * 9dogs / 4cats);
mix-units: (1px + 1em);
invalid-units: (1px * 1px);
.fallback {
  @px: 14px;
  @em: 1.4em;
  @cm: 10cm;
  div-px-1: (@px / @em);
  div-px-2: ((@px / @em) / @cm);
  sub-px-1: (@px - @em);
  sub-cm-1: (@cm - (@px - @em));
  mul-px-1: (@px * @em);
  mul-em-1: (@em * @px);
  mul-em-2: ((@em * @px) * @cm);
  mul-cm-1: (@cm * (@em * @px));
  add-px-1: (@px + @em);
  add-px-2: ((@px + @em) + @cm);
  mul-px-2: ((1 * @px) * @cm);
  mul-px-3: ((@px * 1) * @cm);
}

}