The Situation Calculus and the Fluent Calculus are successful action formalisms that share many concepts. But until now there is no formal relation between the two calculi that would allow to formally analyze the relationship between the two approaches as well as between the programming languages based on them, Golog and FLUX. Furthermore, such a formal relation would allow to combine Golog and FLUX and to ana-lyze which of the underlying computation principles is better suited for different classes of programs. We develop a for-mal translation between domain axiomatizations of the Situ-ation Calculus and the Fluent Calculus and present a Fluent Calculus semantics for Golog programs. For domains with deterministic actions our approach allow...