Figure 7. Graph T obtained by identifying points intersecting red and blue arrows respectively is a digital 2-torus.T. The join T⊕T is the digital homogeneous 5-dimensional surface with a local non-spherical topology. To make this operation visible, the join of a continuous tori T is shown

From

Graph Theoretical Models of Discrete Spaces with Locally Non-spherical Topology

Alexander V. Evako

Applied Mathematics and Physics. 2017, 5(2), 47-52 doi:10.12691/amp-5-2-3