Extracting Duration Facts in Qualitative Simulation using Comparison Calculus

In a previous work, we described the duration consistency filter, which could extract information about the relative lengths of the time intervals (duration facts) in the output of qualitative simulation and use the inconsistencies among them to eliminate spurious behaviors. In this paper, we de-scribe a new method for extracting duration facts that can-not be obtained by our previously described method. The power of the duration consistency filter is therefore in-creased. To prove the correctness of our approach, we have developed a new sign algebra, the Extended Sign Algebra SR1 * and a new comparison formalism; Comparison Calcu-lus