The Dangerous ``All'' in Specifications

Daniel M. Berry

Cheriton School of Computer Science
University of Waterloo
Waterloo, ON, Canada

Erik Kamsties

Fraunhofer Institute for Experimental Software Engineering
Kaiserslautern, Germany


Rupp and Goetz observe that some, but not all, requirement specification sentences involving universal quantification, are dangerous because they are usually not true. Jackson and Zave provide a classification of requirement specification sentences into indicative and optative sentences. It is observed that the dangerous sentences involving universal quantifiers are all indicative.