“An animal may have holes”

“An animal may have holes.” So says the report: “Animal enumerations on regular tilings in Spherical, Euclidean, and Hyperbolic 2-dimensional spaces,” Tomás Oliveira e Silva, July 25, 2013. The author, at the Departamento de Eletrónica, Telecomunicações e Informática, Universidade de Aveiro, Portugal, writes: “An animal with area n is any edge-connected set of n polygons (chosen […]