 On the larger question of the relation between belief revision and defeasible reasoning, there are two possibilities: that a theory of defeasible reasoning should be grounded in a theory of belief revision, and that a theory of belief revision should be grounded in a theory of defeasible reasoning. The second view has been defended by John Pollock (Pollock 1987; Pollock 1995) and by Hans Rott (Rott 1989). On this second view, we must make a sharp distinction between basic or foundational beliefs on the one hand and inferred or derived beliefs on the other. We can then model belief change on the assumption that new beliefs are added to the foundation (and are logically consistent with the existing set of those beliefs). Beliefs can be added which are inconsistent with previous inferred beliefs, and the new belief state consists simply in the closure of the new foundational set under the relation of defeasible consequence. On such an approach, default conditionals can be explicitly represented among the agent’s beliefs. Gärdenfors’s triviality result is then avoided by rejecting one of the assumptions of the theorem, preservation: