EN_KOZAK 20210823.20220813
KOZAK (the name originated by shortening the Czech words for “constant curved shape”) is a geometric four-dimensional (4D) shape enclosed in such a way that its surface represents a 3D space with constant curvature. Just as the 3D surface of a sphere represents a 2D space with constant curvature, and a 2D circle represents a 1D space with constant curvature.