Meta Ontology

How does your information change when you learn that something might be the case, where the modal ''might'' is epistemic? On the orthodox view, a proposition is added to your information base; on the view defended here, no propositions are added to your information base but some are removed from it. I argue that Stephen Yablo's recent attempt to define this removal operation as a kind of propositional subtraction fails, offer a definition of my own in terms of the part--whole relations between the truthmakers of the propositions one accepts, and argue that a deontic analogue of this account solves a problem about permission posed long ago by David Lewis