Action models for knowledge and awareness
Hans van Ditmarsch, Tim French, Fernando R. Velázquez–Quesada · 2012
We considersemantic structures and logics that differentiate betweenbeinguncertainaboutaproposition,beingunaware of a proposition, becoming aware of a proposition and getting to know the truth value of a proposition. In this paper wegiveaunifiedsettingtomodelallthisvarietyofstaticand dynamic aspects of awareness and knowledge, without any constraints on the modal properties of knowledge (or belief —suchasintrospection)orontheinteractionbetweenawareness and knowledge (such as awareness introspection). Our primitive epistemic operator is called speculative knowledge. This is different from the better known implicit knowledge, now definable, which plays amorerestrictedrole. Some dynamicsemanticprimitivesthatareelegantlydefinableinour setting are the actions of ‘becoming aware of apropositional variable’, ‘implicit knowledge’, ‘addressing a novel issue in anannouncement’, andalsomorecomplexwaysinwhichan agentcanbecomeawareofanovelissuebywayofincreasing the complexityofthe epistemicmodel.