Introspective forgetting

Hans van Ditmarsch

Andreas Herzig

pp. 405-423

in: Thomas Ågotnes, Johan van Benthem, Eric Pacuit (eds), Knowledge, rationality & action, Synthese 169 (2), 2009.

Abstract

We model the forgetting of propositional variables in a modal logical context where agents become ignorant and are aware of each others’ or their own resulting ignorance. The resulting logic is sound and complete. It can be compared to variable-forgetting as abstraction from information, wherein agents become unaware of certain variables: by employing elementary results for bisimulation, it follows that beliefs not involving the forgotten atom(s) remain true.