In this paper we describe an algorithm for producing infinitely many examples of set-theoretic complete intersection monomial curves in P n+1 , starting with a single set-theoretic complete intersection monomial curve in P n. Moreover we investigate the numerical criteria to decide when these monomial curves can or cannot be obtained via semigroup gluing.

As a practical foundation for a homotopy theory of abstract spacetime, we propose a convenient category S , which we show to extend a category of certain compact partially ordered spaces. In particular, we show that S ′ is Cartesian closed and that the forgetful functor S →T ′ to the category T ′ of compactly generated spaces creates all limits and colimits.