This library contains code adopted from Ben Pfaff's libavl.  It differs
from marpa_avl, my other adaptation of Ben's libavl in being closer to
the original, and less adopted to Marpa's special needs.  This makes it
more powerful, more general and less efficient.  The marpa_tavl library
is used by Marpa in those cases where it does need the greater power
and generality.

Ben Pfaff's original README is in this directory as README.Pfaff, and
includes the description of his licensing.
