A function is a predefined procedure that computes and returns a result. Functions defined below with a parameter list of list accept two or more arguments separated by commas (,) or semicolons (;). As to which separator is permitted, is defined by the document's listSeparator (§2.15.1.56) element. Arguments to functions can be constants, formulas, or bookmark names that refer to constants or formulas. The functions AVERAGE, COUNT, MAX, MIN, PRODUCT, and SUM can also accept references to table cells as arguments. In the context of a table cell, functions taking a list also accept a single argument that designates a named-list of contiguous cells (§2.16.3.5). Function names are not case-sensitive, and white space can occur between a function's name and its argument list, if any.

The functions supported are as follows:

Functions
Function	Description
ABS(x)	Returns the absolute value of x.
AND(x,y)	Returns 1 if the logical expressions x and y are both true; otherwise, it returns 0.
AVERAGE(list)	Returns the average value of the items in list.
COUNT(list)	Returns the number of items in list.
DEFINED(x)	Returns 1 if the expression x is well formed; otherwise, it returns 0.
FALSE	Returns 0.
INT(x)	Returns the value of the integer part of x.
MAX(list)	Returns the largest value in list.
MIN(list)	Returns the smallest value in list.
MOD(x,y)	Returns the value x - ny, for some integer n such that, if y is nonzero, the result has the same sign as x and magnitude less than the magnitude of y. If y is zero, a diagnostic shall be issued. (y need not be a whole number.) [Example: MOD(21,5) results in 1 MOD(21,-5) results in 1 MOD(-21,5) results in -1 MOD(-21,-5) results in -1 end example]
NOT(x)	Returns 0 if the logical expression x is true, or 1 if the expression is false.
OR(x,y)	Returns 1 if either or both logical expressions x and y are true; otherwise, it returns 0.
PRODUCT(list)	Returns the result of multiplying together all members in list.
ROUND(x,y)	Returns the value of x rounded to the specified number of decimal places indicated by floor(y), where floor has the mathematical meaning. If y is negative, any fractional part is discarded and the integer part of the value is rounded to the corresponding power of 10.
SIGN(x)	Returns 1 if x is positive; returns 0 if x is zero; and returns –1 if x is negative.
SUM(list)	Returns the sum of the items in list.
TRUE	Returns 1.