Public announcements, public assignments and the complexity of their logic

Hans van Ditmarsch, Andreas Herzig, Tiago de Lima
2012 Journal of Applied Non-Classical Logics  
We study the extension of public announcement logic PAL by public assignments, that we call PALA. Just as in the case of PAL, the standard procedure for deciding PALA validity, i.e., the use of so-called reduction axioms to translate PALA formulae into formulae in epistemic logic EL, may lead to exponential growth. In this paper, we show that such price is not mandatory, for we provide a polynomial translation of PALA into EL. This is based on abbreviations of subformulae by new propositional
more » ... tters. Such optimal translation also enables us to show the computational complexity of the problem of deciding PALA validity, which turns out to be coNP-complete in the single-agent case and PSPACE-complete in the multiagent case.
doi:10.1080/11663081.2012.705964 fatcat:56r5waj2r5dobblkcuxnii7yga