摘要
This paper presents a characterization of the embeddability on a surface of genus arbitrarily given for a graph. Its specific case for the surface of genus zero leads to the famous planarity theorems given independently by Whitney via duality, MacLane via cycle basis and Lefschetz via double covering at a time.
This paper presents a characterization of the embeddability on a surface of genus arbitrarily given for a graph. Its specific case for the surface of genus zero leads to the famous planarity theorems given independently by Whitney via duality, MacLane via cycle basis and Lefschetz via double covering at a time.
