






















In this note we show that any embedded graph has a checkerboard colourable twisted dual and any Eulerian embedded graph has a checkerboard colourable partial Petrial, answering questions posed by Ellis-Monaghan and Moffatt. The proofs are based on orientations of their medial graphs and orientations of boundary components of their corresponding ribbon graphs. The arrow presentations of ribbon graphs are also used. We also obtain two related results.
此内容由惯性聚合(RSS阅读器)自动聚合整理,仅供阅读参考。 原文来自 — 版权归原作者所有。