A model of epistemic change in belief sets that is iterable and based on polynomials is reported on in this paper. An epistemic state, encoding uncertain information, is represented by a total preorder on the set of all interpretations (states, worlds) of our underlying knowledge representation language. Such preorders are given a representation as polynomials over the Boolean semiring ={0,1}. Revision operators are then also interpreted in terms of polynomials.

The idea is interesting, and will hopefully be the subject of considerable further study. One should also ask whether it might not be useful to replace with some other suitable semiring.