Using Default Reasoning to Discover Inconsistencies in Natural Language Requirements

The use of logic in identifying and analysing inconsistencyin requirements from multiple stakeholders has been found tobe effective in a number of studies.Default reasoning is atheoretically well founded formalism that is especially suitefor supporting the evolution of requirements.However, directuse of logic in eliciting requirements an in discussing themwith stakeholers poses serious useability problems.In thispaper we explore the integration of natural language parsingtechniques with default reasoning to overcome these if difficulties. We also propose a method for automatically discovering scenarios that expose inconsistencies in requirements, and show how to deal with them in a formal manner.These techniques were implemented and tested in a prototype tool called CARL.