Dear all, I'm looking for examples of symmetric monoidal bicategories (where the structure is genuinely weak, i.e. the various isomorphisms are not identities) and I would appreciate some help. -- Actually, strict 2-categories with (genuinely) weak monoidal structure would be even more interesting, but I found it almost impossible to find anything on that. As I am using these categories as models, I need some structure that is "concrete enough" to do calculations with (while being as simple as possible). Right now I'm considering the bicategory of rings (or monoids or fields), bimodules over them, and bimodule homomorphisms, where the monoidal structure is defined by the tensor product etc. (Pointers to detailed accounts of this category would be very much appreciated, too. I've only found fairly sketchy mentions in the literature.) I would be grateful about any other examples of this kind! Thanks, Roman [For admin and other information see: http://www.mta.ca/~cat-dist/ ]