From a category theoretic point of view, subtraction is a natural candidate for comparison: It is the internal hom-functor in the ordered monoid of integers. On

From a category theoretic point of view, subtraction is a natural candidate for comparison: It is the internal hom-functor in the ordered monoid of integers. One could argue that internal hom functors are the very essence of a "comparison". The sole problem seems to be that integers in C are not actually integers.