e list of <em>Coxeter generators</em>)</li><li><code>nref(W)</code> which  returns the  number of  reflections of  <code>W</code>, if  <code>W</code> is  finite or <code>nothing</code> if <code>W</code> is infinite.</li></ul><p>It  should  be  noted  that  a  Coxeter  group  can  be <em>any</em> kind of group implementing the above functions.</p><p>Because  of the  easy solution  of the  word problem  in Coxeter  groups, a convenient  way  to  represent  their  elements  is as words in the Coxeter generator