!"# #$ !"# $% "#% " " # #$ # " ""! !"# "" " # $ # %"" !"# " "" !" "" # # % $" " %" !" %" #"" %$" ! $%$" "" %% % % ! %"" $" #$ " # %% & !% ’%# $ $%$" "" %% (!) *$% "#% +%$" "" %% +"% % % " " 1. Introduction Epistemic logic is a language for reasoning about the individual or groups knowledge of agents in a system. Majority of the systems are dynamics and the knowledge or the group knowledge of the agents will change by the actions. Distributed knowledge is a notion of group knowledge. Consider the following example. Sara was killed last week. An investigator works on it. In the Judge’s private office, the investigator declares the two following facts to the judge. : The knife was in the dresser of the bedroom when the murderer killed Sara. : If Anna knows the above statement then her husband is innocent. Peradventure, Anna knows , and she is sitting in the court's yard right now. The judge goes to ask Anna about the place of the knife. Before judge reaches to Anna, a