TAHTA 4D NO FURTHER A MYSTERY

In three Proportions, a circle could be extruded to sort a cylinder. In 4 dimensions, there are plenty of various cylinder-like objects. A sphere can be extruded to get a spherical cylinder (a cylinder with spherical "caps", often called a spherinder), plus a cylinder may be extruded to obtain a cylindrical prism (a cubinder). Lagrange wrote in hi