The following functions may be used in the expression to be evaluated (and not directly following the $fn: keyword). Function names may be in upper or lower case. X and Y represent values passed to the built-in expression function:

SQR(X) returns square value of X
SIN(X) returns sine of X
COS(X) returns cosine of X
ATAN(X)returns arc-tangent of X
SINH(X) returns hyperbolic sine of X
COSH(X) returns hyperbolic cosine of X
COTAN(X) returns co-tangent of X
TAN(X) returns tangent of X
EXP(X) returns exponential of X
LN(X) returns natural logarithm of X
LOG(X) returns base ten logarithm of X
SQRT(X) returns square root of X
ABS(X) returns absolute value of X
SIGN(X) returns -1 if X negative else 1
TRUNC(X) returns integer portion of X
CEIL(X) returns lowest integer greater than or equal to X
FLOOR(X) returns highest integer less than or equal to X
RND(X) returns random integer between 0 and X
RANDOM(X) returns random value between 0 and X
INTPOW(X,Y) returns value of X raised to integral power of Y
POW(X,Y) returns value of X raised to power of Y
LOGN(X,Y) returns logarithm base X of Y
MIN(X,Y) returns minimum value of X or Y
MAX(X,Y) returns maximum value of X or Y
IF(BOOL,X,Y)returns X if BOOL non-zero, else Y (both X and Y are evaluated)

The expression may also contain the following arithmetical operators:

+add
-subtract
*multiply
/divide
^power

In a boolean expression, the following operators may be used:

=equal
<>not equal
> greater than
<less than
>=greater than or equal
<=less than or equal

Parentheses ( ) should be used to control the parsing of complex expressions