Lecture Notes in Computer Science 1783 EditedbyG.Goos,J.HartmanisandJ.vanLeeuwen 3 Berlin Heidelberg NewYork Barcelona HongKong London Milan Paris Singapore Tokyo Tom Maibaum (Ed.) Fundamental Approaches to Software Engineering Third International Conference, FASE 2000 Held as Part of the Joint European Conferences on Theory and Practice of Software, ETAPS 2000 Berlin, Germany, March 25 –April 2, 2000 Proceedings 1 3 SeriesEditors GerhardGoos,KarlsruheUniversity,Germany JurisHartmanis,CornellUniversity,NY,USA JanvanLeeuwen,UtrechtUniversity,TheNetherlands VolumeEditor TomMaibaum King’sCollegeLondon DepartmentofComputerScience Strand,LondonWC2R2LS,UK E-mail:[email protected] Cataloging-in-PublicationDataappliedfor DieDeutscheBibliothek-CIP-Einheitsaufnahme Fundamentalapproachestosoftwareengineering:thirdinternational conference;proceedings/FASE2000,heldaspartoftheJoint EuropeanConferencesonTheoryandPracticeofSoftware,ETAPS2000, Berlin,Germany,March25-April2,2000.TomMaibaum(ed.).-Berlin; Heidelberg;NewYork;Barcelona;HongKong;London;Milan; Paris;Singapore;Tokyo:Springer,2000 (Lecturenotesincomputerscience;Vol.1783) ISBN3-540-67261-3 CRSubjectClassification(1991):D.2,D.3,F.3 ISSN0302-9743 ISBN3-540-67261-3Springer-VerlagBerlinHeidelbergNewYork Thisworkissubjecttocopyright.Allrightsarereserved,whetherthewholeorpartofthematerialis concerned,specificallytherightsoftranslation,reprinting,re-useofillustrations,recitation,broadcasting, reproductiononmicrofilmsorinanyotherway,andstorageindatabanks.Duplicationofthispublication orpartsthereofispermittedonlyundertheprovisionsoftheGermanCopyrightLawofSeptember9,1965, initscurrentversion,andpermissionforusemustalwaysbeobtainedfromSpringer-Verlag.Violationsare liableforprosecutionundertheGermanCopyrightLaw. Springer-VerlagisacompanyintheBertelsmannSpringerpublishinggroup. ©Springer-VerlagBerlinHeidelberg2000 PrintedinGermany Typesetting:Camera-readybyauthor,dataconversionbyBollerMediendesign Printedonacid-freepaper SPIN10719952 06/3142 543210 Foreword 000 r o uro o o r o or r o o r u r o r o u r o o r r o r o r or o o ur u o u or o r r rou o o ro u o o ro u o oo oo u or r o r o or r r r r o o r or r o o o o ou r o o r o u o o r o r u r r o o r o o u oo o r o r o r ro r o ro or o o o ro o o o r u o r o r ro r o ur r o o o ur r r r or u o o o r o o r o o r o o o r ro or u r r r r or o o o o oru o r ou r r r r r o o r or r r or r r r ro r o 000 u u u r r o oru o r ou r u ur or o o o r r o o ou oo ro 000 o r o r or o o r r r r r u r ro r oor o r r r o ¨ u o u u r o o r r u u r or ¨ r o r ro u r r o r or o r r o o r o o urr r VI Foreword o o o r r r r oo o r u r r o ro o r u u r u r r o uro o r u r ¨ r u r o u o o r r or u o o r o r u r o r r o r o r ru¨ o¨ or o ur r o r ru¨ r r or u o o r ur r o r r ru¨ 000 r rou o or ro u or o u o o r oo o r uro o o or ro r u uro o o or or o u r uro o o or o r oo o r o o o uro o o r or ro r ou o r r r u o o o or o ro r o r o o r or r o r r r r or r o u ro u r 000 o r o r Preface r r r gi ri g i r r i i i r i i g r r rig r i i i gi r r r r i r i i r rr i g r i r r r i i r ri r i r i i i i i i r i i r gi ri grig r ri i i gi r i i i i i i r r ri i i ig r i gi i i i g i r i i i i r r i i ri g r r r r r r i i i r r gi ri g i i i r gi ri g r ir gi ri g ig i i r r gr i i r gi ri g ri i r r g i gr i g r r i ri i r i i g ri g r r i i r i g gi ri g r ri r i i r i r r r r gi ri g r r r i ri i r r gi ri g r r i i g i – r ig ig i r r i g r r i i r i g i i – r gr ri i r r i r r r i – gr i r i i gi ri g i – i i g r gr i gi r gr i gi rg r r i r – ri i r r r gi ri g g r r i – i i i ri i r gi ri g – r i g i ri ri r gi ri g – ig r ri i i i ii ri i VIII Preface r gr i i g i ri i i r i i r ig i ri ¨ r i rg r ig r r r i ri g i i ir i ri i i rr i i ri i r ri i i ri r ig i ri i i ri r i r r r g ri g i ir i g g i ri i i i i i r i r i i ri ri r i ri r r r i i ri r r i 0 r r i r i i i i ri r r i i g i i i r r r gr r r r i i i r r i i r i ri i r r r i i r i ri r r r r r i r i i g r i r r i r i i i i i 21 r i ir i r r r r r i r r r r i r i g i r g i ig r r ri i i i r ig i i i r r i ri i rig i g r gi ri g r r rigi r i i g i i i i r r r r i i r ir i r r r r gi ri g i i i r r i i i r i i g r r g i i r i r i r r r ri i r iri i r r rr r i r r r i i i r i ii i i i gi r i r ii i r i Referees (cid:2) (cid:2)