  In  Baker 1989,  Andrew Baker presented a solution to the version of the Yale Shooting problem in the Situation Calculus, using a circumscriptive inertial axiom. The very brief account of circumscription above in  Section 3 indicated that circumscription uses preferred models in which the extensions of certain predicates are minimized. In the course of this minimization, a set of parameters (including, of course, the predicates to be minimized) is allowed to vary; the rest are held constant. Which parameters vary and which are held constant is determined by the application. 