2-$2$ -半等值环映射的一致覆盖
2-uniform covers of $2$-semiequivelar toroidal maps
摘要：
如果贴图中的每个顶点都有两种面循环类型中的一种，则称该贴图为$2$ -半等值面。2-均匀平铺是具有$2$不同传递性顶点类的正多边形的边到边平铺。显然，$2$ -一致映射是$2$ -半等价映射。这一点的反面一般来说并不正确。平面上有20个不同的2-均匀平铺（这些是$14$不同类型的）。本文证明了一个$2$ -半等维环面映射$K$有一个有限的$2$ -一致覆盖，如果$K$的泛覆盖是$2$ -一致的，除了两种类型.
英文摘要：
If every vertex in a map has one out of two face-cycle types, then the map is said to be $2$-semiequivelar. A 2-uniform tiling is an edge-to-edge tiling of regular polygons having $2$ distinct transitivity classes of vertices. Clearly, a $2$-uniform map is $2$-semiequivelar. The converse of this is not true in general. There are 20 distinct 2-uniform tilings (these are of $14$ different types) on the plane. In this article, we prove that a $2$-semiequivelar toroidal map $K$ has a finite $2$-uniform cover if the universal cover of $K$ is $2$-uniform except of two types.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
