The lack of fact-oriented, time-dependent formalizations of conceptual models leads to difficulties in inspecting and reasoning about system properties and predicting future behavior from past behavior. We can better serve these needs by formalized conceptualizations that more closely match the demands of such applications. We therefore set forth in this chapter a fact-oriented, time-dependent formalism, called
, for object existence, object interrelationships, object behavior, and object interaction. OSM-Logic is formally grounded in predicate calculus, and is thus mathematically sound and well defined.