Reducing ambiguity in qualitative reasoning

Qualitative reasoning derives the behavior of a physical system using a representation of the fundamental principles for the domain. In qualitative reasoning parameters are mapped into intervals covering the relevance values. The mapping can introduce ambiguity into the qualitative solution, possibly rendering the solution meaningless. The qualitative calculus defines valid operations between the qualitative parameters. A parameter has relationships, such as greater than, equal to, or smaller than, with other parameters. Four techniques, basic calculus operations with parameter relations, transitivity relationships, constant elimination, and consistency checking, can be used to avoid the ambiguity in the qualitative reasoning process.