Dear categorists, the following preprint, now available on arXiv, is related to a recent discussion on this list and may be of interest to some of you: Some remarks on multicategories and additive categories Abstract: Categories are coreflectively embedded in multicategories via the "discrete cocone" construction, the right adjoint being given by the monoid construction. Furthermore, the adjunction lifts to the "cartesian level": preadditive categories are coreflectively embedded (as theories for many-sorted modules) in cartesian multicategories (general algebraic theories). In particular, one gets a direct link between two ways of considering modules over a rig, namely as additive functors valued in commutative monoids or as models of the theory generated by the rig itself. Comments are of course welcome. I also hope that someone will help me to fill the gap in the proof of proposition 3.8. Best regards, Claudio [For admin and other information see: http://www.mta.ca/~cat-dist/ ]