In geometry, an apeirogonal prism or infinite prism is the arithmetic limit of the family of prisms; it can be considered an infinite polyhedron or a tiling of the plane. Thorold Gosset called it a 2-dimensional semi-check, like a single row of a checkerboard. If the sides are squares, it is a uniform tiling. If colored with two sets of alternating squares it is still uniform. * Uniform variant with alternate colored square faces. * Its dual tiling is an apeirogonal bipyramid.