Abstract
This paper presents logical representations for causality and temporal reasoning by using these representations. First, a causal relation is interpreted by using two logical relations. One relation represents that if a cause state is occurred, an effect state will be occurred. Another relation represents that if an effect state doesn't exist and all of causes doesn't exist, an effect state will not exist. By using these two basic relations, three more logical relations are given. First one is that if an effect doesn't exist, causes didn't exist. Second one is that if an effect exists and causes didn't exist, an effect existed. Last one is that if an effect didn't exist and an effect exist at the next time, one of causes existed at least. And also, definite causality and possible causality are considered in these logical relations. These logical representations give us various interpretations about causality. These representations are applied to a protection system of a substation. Finally, program was developed based on these ideas. Results of temporal reasoning about states which have causal relations to another states are shown.
