protected function opCmpNumberNumber($left, $right)
    {
        $n = $left[1] - $right[1];

        return new Node\Number($n ? $n / abs($n) : 0, '');
    }
protected function opCmpNumberNumber($left, $right)
    {
        $n = $left[1] - $right[1];

        return new Node\Number($n ? $n / abs($n) : 0, '');
    }
protected function opCmpNumberNumber ( $ left , $ right ) { $ n = $ left [ 1 ] - $ right [ 1 ] ; return new Node \ Number ( $ n ? $ n / abs ( $ n ) : 0 , '' ) ; }
Three-way comparison, aka spaceship operator

@param array $left
@param array $right

@return \Leafo\ScssPhp\Node\Number
Three - way comparison aka spaceship operator