-- Lots of merging can end up deleting all
of the new facets for a point.  This is a rare event that has
only been seen while debugging the code.

<p>
<li><b>Triangulated output leads to precision problems</b> -- With sufficient
merging, the ridges of a non-simplicial facet may have serious topological
and geometric problems.  A ridge may be between more than two
neighboring facets.  If so, their triangulation ('<a href="qh-optq.htm#Qt">Qt</a>')
will fail since two facets have the same vertex set.  Furtherm