Math doesn't contain any variables, only functions and a constant.

Variable name	Variable type	Description
if_then_else(x,y,z)	function, x = boolean, y/z = any type, return y or z	if then else structure, x = condition, y = return/execute if true, z = return/execute if false (x ? y : z)
add(x,y)	function, x & y = decimal, return decimal	adds two numbers together (x + y)
subtract(x,y)	function, x & y = decimal, return decimal	subtracts y from x (x - y)
divide(x,y)	function, x & y = decimal, return decimal	divides x by y (x / y)
mod(x,y)	function, x & y = decimal, return decimal	modulus, remaining of the division x by y (x % y)
multiply(x,y)	function, x & y = decimal, return decimal	multiplies x by y (x * y)
negate(x)	function, x = decimal, return decimal	invert sign of x (-x)
posivate(x)	function, x = decimal, return decimal	posivate (x)
pow(x,y)	function, x & y = decimal, return decimal	x raised to the y power (x ^ y)
pi	constant	gives a value of 3.1415926535....
cos(x)	function, x = decimal, return decimal	returns the cosine of x
sin(x)	function, x = decimal, return decimal	returns the sine of x
tan(x)	function, x = decimal, return decimal	returns the tangent of x
acos(x)	function, x = decimal, return decimal	returns the inverse cosine of x
asin(x)	function, x = decimal, return decimal	returns the inverse sine of x
atan(x)	function, x = decimal, return decimal	returns the inverse tangent of x
HSL2RGB(x)	function, x = list of 3 decimals, return list of 3 decimals	Convert [H(ue),S(aturation),L(ightness)] to [R(ed),G(reen),B(lue)]
HSL2RGB(x)	function, x = list of 4 decimals, return list of 4 decimals	Convert [H(ue),S(aturation),L(ightness),A(lpha)] to [R(ed),G(reen),B(lue),A(lpha)]
RGB2HSL(x)	function, x = list of 3 decimals, return list of 3 decimals	Convert [R(ed),G(reen),B(lue)] to [H(ue),S(aturation),L(ightness)]
RGB2HSL(x)	function, x = list of 4 decimals, return list of 4 decimals	Convert [R(ed),G(reen),B(lue),A(lpha)] to [H(ue),S(aturation),L(ightness),A(lpha)]
HSV2RGB(x)	function, x = list of 3 decimals, return list of 3 decimals	Convert [H(ue),S(aturation),V(alue)] to [R(ed),G(reen),B(lue)]
HSV2RGB(x)	function, x = list of 4 decimals, return list of 4 decimals	Convert [H(ue),S(aturation),V(alue),A(lpha)] to [R(ed),G(reen),B(lue),A(lpha)]
RGB2HSV(x)	function, x = list of 3 decimals, return list of 3 decimals	Convert [R(ed),G(reen),B(lue)] to [H(ue),S(aturation),V(alue)]
RGB2HSV(x)	function, x = list of 4 decimals, return list of 4 decimals	Convert [R(ed),G(reen),B(lue),A(lpha)] to [H(ue),S(aturation),V(alue),A(lpha)]
addlist(x,y)	function, x & y = list, return list	add two lists together (x ++ y)
boolnegate(x)	function, x = boolean, return boolean	invert x (!x)
comp.	sub group	See Math.comp.
and(x,y)	function, x & y = boolean, return boolean	boolean logic AND, return true if both are true (x && y)
or(x,y)	function, x & y = boolean, return boolean	boolean logic OR, return true if any is true (x || y)

From Phun Beta 5.28