This section describes various actions and functions which may be used on the LHS and RHS of rules, from the toplevel command prompt, and from other constructs such as deffunctions, defmessagehandlers, and defmethods. The terms functions, actions, and commands should be thought of interchangeably. However, when the term function is used it generally refers to a function which returns a value. The term action refers to a function having no return value but performing some basic operation as a side effect (such as printout). The term command refers to functions normally entered at the toplevel command prompt (such as the reset command, which does not return a value, and the set-strategy command, which does return a value).

12.1 PREDICATE FUNCTIONS