Knowledge and implicit knowledge in a distributed environment: preliminary report

Abstract: We characterize the states of knowledge that are attainable in distributed systems, where communication is done by unreliable message exchange. The reason that certain states of knowledge are unattainable is a conservation principle which says that information about “nature ” that can be obtained by combining all of the knowledge of the members of a closed system is preserved. We axiomatize the class of formulas in the propositional modal logic of knowledge that are valid in attainable knowledge states, and we determine the complexity of the decision problem