不可定向

如果曲面是可定向的，那么称这个地图是可定向的，否则，称做不可定向的。

A map is said to be orientable if the supporting surface is orientable . Otherwise , said to be non-orientable .

为Mobius带选一个始终如一的的法向量是不可能的，这就是所谓的不可定向的曲面。

There 's no way to choose consistently a normal vector for the Mobius strip So , that 's what we call a non-orientable surface .

对于不可定向曲面上地图的计数，大部分的文献都是集中在小亏格的曲面上，如射影平面，Klein瓶等。

On the enumeration of maps on the nonorientable surfaces , most of literatures concentrated on such surfaces as the projective plane and the Klein bottle .

图的不可定向最大亏格

The maximum non - orientable genus of a graph

一个不可定向地图，如果只有一个顶点和一个面，则称它为一个魔。

A nonorientable map with one vertex and one face is called a barfly .

对于给定的棱数，得到不同构的可定向与不可定向根瓣丛的数目。

For the size given , extract the numbers of orientable and nonorientable nonisomorphic rooted pedal bundles .

不可定向地图组合分类

Combinatorial classification of nonorientable maps

对于一类特殊的魔，称为简魔，论证了棱数不同的简魔不可能初等等价，任何一个不可定向地图都与某个简魔初等等价。

For a type of special barflies , said to be simplified , it is shown that two simplified barflies of different sizes are not basic equivalent and that any nonorientable map is basic equivalent to one of the simplified barflies .