tracking
algorithm in [<a
href="./bibliography.html#fortin96:_graph_iso_prob">46</a>,<a
href="./bibliography.html#reingold77:_combin_algo">48</a>].  The file
<a href="./isomorphism-impl.pdf">isomorphism-impl.pdf</a> contains a (somewhat out-of-date)
&quot;literate&quot; description of the implementation.  The algorithm
used is simple but slow. A more efficient (and much more complex)
algorithm is described in [<a
href="./bibliography.html#mckay81:_pract_graph_iso">47</a>]. When (and
if) a version of this al