Constraint logic programming for structure-based reasoning about dynamic physical systems

The paper describes a constraint logic programming approach for reasoning about dynamic physical systems based on structure. The approach takes a bond graph model of a system and computes a causal graph representation of its causal structure. Causal graphs can be used for causal explanations and for explicating the eeect of modeling abstractions on causal structure. The paper shows how causal graphs can be used to compute a simulation model of a system in the form of a set of diier-ential algebraic equations. The topological properties of the causal graph determines whether a simulation model is regular, i.e., conforming to the criterion of \real-time representation" or causality. In case the simulation model is not regular, a method is given for identifying all causal problems of a bond graph model.