Now showing items 1-1 of 1

    • Non repetitive walks in graphs and digraphs 

      Currie, James Daniel (The University of CalgaryUniversity of Calgary, 1987-06)
      A word $w$ over alphabet $\Sigma$ is {\em non-repetitive} if we cannot write $w=abbc$, $a,b,c\in\Sigma^*$, $b\ne\epsilon$. That is, no subword of $w$ appears twice in a row in $w$. In 1906, Axel Thue, the Norwegian number ...