on"></a>

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<pre>
<i>bracket-expression</i> ::= <b>"["</b> <i>item</i>+ <b>"]"</b>
                   |   <b>"[^"</b> <i>item</i>+ <b>"]"</b>
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<p>
A bracket expression specifies a set of characters by enclosing a
nonempty list of items in brackets.  Normally anything matching any
item in the list is matched.  If the list begins with <tt>^</tt> the
meaning is negated; any character matching no item in the list is
matched.
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<p>
