>
</p><p>There are others, such as trigonometric operators, that are not implemented yet, because I did not find a use for them in my work. Should you need them, press me.</p><h2>Calling generic function on nodes content<a name="7"></a></h2><p>Another solution, if you do not find happiness with the above operators, is to call a generic function on the nodes content. There is two methods to do that.</p><p><b><tt>treefun</tt></b> apply a 1-argument function on the content of each node and generate a new tree 