KRL has several libraries that are useful for dealing with special data types and extend the allowed functions. In general, to reference a function from a library, you use the following syntax:
<library-name>:<function-name>(<arg0>,<arg1>,...,<argn>)
The following sections describe a few of the most useful built-in libraries. For information on other libraries, as well as more detail on the ones reviewed here, see the KRL documentation.