Representing Relative Temporal Knowledge with TAND Connective

Several temporal models have been introduced to represent and reason temporal knowledge. These models are mainly based on the point based or interval based time theories. However both point based and interval based time models have their own weaknesses. Allen points out that there can be a time point in point based models where either two events could occur at the same time or none would occur. Galton shows weaknesses in interval based time models. On the other hand, standard logical connective AND does not represent temporal order of events. The AND connective is more suitable for concurrent events rather than for sequential events. Hence in this paper we suggest a new temporal logical connective TAND to represent sequential events and redefine the standard logical connective AND to represent concurrent events. TAND increases the expressive power of the temporal logic. We show how incomplete relative temporal relations can be represented using TAND and AND connectives.