comparable($number1, $number2) Returns whether two numbers can added, subtracted, or compared.

alpha($color) Returns the alpha component (opacity) of a color. This is 1 unless otherwise specified. This

floor($number) Rounds a number down to the previous whole number.

ie_hex_str($color) Converts a color into the format understood by IE filters.

opacify($color, $amount) Also known as: fade_in Makes

str_index($string, $substring) Returns the index of the first occurrence of $substring in $string

change_color($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha]) Changes one or more properties

to_lower_case($string) Convert a string to lower case,

selector_nest($selectors...) Return a new selector with all selectors in $selectors nested beneath one another

selector_unify($selector1, $selector2) Unifies two selectors into a single selector that matches only elements matched by