i recall looking over some years ago a very nice extended cartoon (it would be more apt to call it a graphical-novel proof, almost) of a theorem in mathematical logic, or maybe category theory. the illustration is not at a high level (ie it's not like, for example LOGICOMIX, but more like XKCD), but the math is real and quite detailed. it was not published book as far as i know. it is also not anything from XKCD. the subject matter was perhaps model theory, but i don't really remember. it features lots of simple characters with thought bubbles that contain embedded other bubbles, where what's in the bubbles is quite helpful for following the logic of the proof. i'd welcome a pointer to it if this rings a bell for anyone. -- Thane Plambeck tplambeck@gmail.com http://counterwave.com/