Built-in functions are similar to operation codes in that they perform operations on data you specify. Built-in functions can be used in expressions. Additionally, constant-valued built-in functions can be used in named constants. These named constants can be used in any specification.

All built-in functions have the percent symbol (%) as their first character. The syntax of built-in functions is:

function-name{(argument{:argument...})}  

Arguments for the function may be variables, constants, expressions, a prototyped procedure, or other built-in functions. An expression argument can include a built-in function.