Improving on Domokos’s improvement of Swan’s theorem, we show that under certain conditions on a finite digraph, whenever \(p,q\) are vertices, then the number of even Eulerian paths from \(p\) to \(q\) is the same as the number of odd ones from \(p\) to \(q\).
Citation
James H.Schmerl. Even and Odd Eulerian Paths[J], Ars Combinatoria, Volume 097-A. 97-99. .