| 释义 |
orientable A surface is orientable if it is two-sided—such as the plane or sphere—and is otherwise non-orientable—such as the Möbius band or Klein bottle, which are one-sided surfaces. A closed surface in R3 has an inside and outside and so is orientable. The notion of orientability can be extended to higher-dimensional manifolds. See also Classification Theorem for Surfaces.
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