Realizing Public Announcements by Justifications

TitleRealizing Public Announcements by Justifications
Publication TypeJournal Article
Year of Publication2014
AuthorsBucheli, S, Kuznets, R, Studer, T
JournalJournal of Computer and System Sciences
KeywordsBelief revision, Dynamic epistemic logic, justification logic, Public announcements
AbstractModal public announcement logics study how beliefs change after public announcements. However, these logics cannot express the reason for a new belief. Justification logics fill this gap since they can formally represent evidence and justifications for an agent's belief. We present ${\sf OPAL(K)}$ and ${\sf JPAL(K)}$, two alternative justification counterparts of Gerbrandy–Groeneveld's public announcement logic ${\sf PAL(K)}$. We show that ${\sf PAL(K)}$ is the forgetful projection of both ${\sf OPAL(K)}$ and ${\sf JPAL(K)}$. We also establish that ${\sf JPAL(K)}$ partially realizes ${\sf PAL(K)}$. The question whether a similar result holds for ${\sf OPAL(K)}$ is still open.