token classes</I>. Literals (like &quot;while&quot; and
&quot;&gt;=&quot;) may be incorporated directly into productions as
strings, and do not have to be named. Token classes (such as identifiers or
numbers) must be named, and have structures that are specified by regular
expressions, defined in EBNF. There are usually many different instances of a
token class (e.g., many different identifiers) which are all recognized as the
same kind of token. </P>

<P>A scanner specification consists of six optional par