Alun D. Preece Clifford Grossner Thiruvengadam Radhakrishnan Validating dynamic properties of rule-based systems. 145-169 1996 44 Int. J. Hum.-Comput. Stud. 2 http://dx.doi.org/10.1006/ijhc.1996.0008 db/journals/ijmms/ijmms44.html#PreeceGR96