The Euclidean flune is a flat, infinitely large four-dimensional space following the rules of four-dimensional Euclidean geometry. It can be created by taking the cartesian product of four copies of the Euclidean line. A flune can be used to bisect a peton, and polytera can have realms of symmetry through which they can be reflected. Taking multiple flunic cross sections of a polyteron can give insight into its structure, though embedding this in three dimensions can still be a challenge without taking further realmic cross sections of the flunic cross sections themselves.