Indeed, in projective geometry a cylindrical surface is just a special case of a conical surface. Multiplication is just a special case of integration, namely integrating a constant function. a singleton is just a special case of a pair

Indeed, in projective geometry a cylindrical surface is just a special case of a conical surface.

Multiplication is just a special case of integration, namely integrating a constant function.

a singleton is just a special case of a pair