></li>
</ol></dd>


<dt>arr_c</dt>
<dd><p>Arrow code for symbols at ends of probability links
(as a numeric value <code>-3 &lt;= arr_c &lt;= +6</code>),
with the following options:</p><ul><li><p><code>-1</code> to <code>-3</code>: points at one/other/both end/s;</p></li>
<li><p><code>0</code>: no symbols;</p></li>
<li><p><code>+1</code> to <code>+3</code>: V-arrow at one/other/both end/s;</p></li>
<li><p><code>+4</code> to <code>+6</code>: T-arrow at one/other/both end/s.</p></li>
</ul><p>Default: <code>arr