3>Basic Symbols</h3>

    The basic symbols of Obr are its identifiers, denotations, and
    delimiters.  The following regular expressions describe the
    structure of identifiers and integers in Obr.

<pre>
Identifier: [a-zA-Z][a-zA-Z0-9]*
Integer: [0-9]+
</pre>

    Upper- and lower-case versions of the same letter are distinct.
    The delimiters and other denotations of the language are the
    following special characters and keywords:

<pre>
( ) : ; + - * = , := ~ # &lt; &gt; . [ ] .. |
AND ARRAY BE