
Conjecture Let
be an eulerian graph of minimum degree
, and let
be an eulerian tour of
. Then
admits a decomposition into cycles none of which contains two consecutive edges of
.






Kotzig proved the converse statement:
Theorem Let
be an eulerian graph of minimum degree
and let
be a decomposition into cycles of
. Then
admits an eulerian tour such that none of the
,
, contains two consecutive edges of
.








For more details on eulerian graphs, see [F].
Bibliography
*[F] H. Fleischner. Eulerian Graphs and Related Topics. Part 1. Vol. 1. Annals of Discrete Mathematics, Vol. 45, (1990) North-Holland, Amsterdam.
* indicates original appearance(s) of problem.