he error. By default, this is generated automatically.</p></dd>


<dt>supplement</dt>
<dd><p>Optional. A (named) character vector which gives some
additional information about the error. The names are used to create
bullets, see <code><a href="throw.html">throw()</a></code>. By default, this is left empty.</p></dd>


<dt>zero</dt>
<dd><p>Optional. <code>TRUE</code> or <code>FALSE</code> which indicates if zero is
acceptable. The default value is <code>FALSE</code>.</p></dd>


<dt>...</dt>
<dd><p>Optional. A