令Γ是S^3中的一个抽象平面图,Γ’是在图Γ上加上有限条边后所得到的图.主要考虑图Γ’的抽象平面性,并且给出了Γ’是抽象平面图的一个充要条件,另外还从平坦嵌入的角度对平面图做了一些讨
Let Γ be an abstractly planar graph in S^3 , and Γ' a graph obtained by adding a finite number of edges to Γ. The abstract planarity of Γ' is considered. A necessary and sufficient condition under which Γ' is abstractly planar is given. Some discussions of planar graph in the viewpoint of flat embedding are done.