suchquestionsforcenturies(unrestrictedbythecapabilitiesofanyhard- ware). Theprinciplesgoverningtheinteractionofseveralprocesses,forexample, areabstractansimilartoprinciplesgoverningthecooperationoftwolarge organisation.Adetailedrulebasedeffectivebutrigidbureaucracyisvery muchsimilartoacomplexcomputerprogramhandlingandmanipulating data. Myguessisthattheprinciplesunderlyingoneareverymuchthe sameasthoseunderlyingtheother. Ibelievethedayisnotfarawayinthefuturewhenthecomputerscientist willwakeuponemorningwiththerealisationthatheisactuallyakindof formalphilosopher! TheprojectednumberofvolumesforthisHandbookisabout18.The subjecthasevolvedanditsareashavebecomeinterrelatedtosuchanextent thatitnolongermakessensetodedicatevolumestotopics.However,the volumesdofollowsomenaturalgroupingsofchapters. Iwouldliketothankourauthorsarereadersfortheircontributionsand theircommitmentinmakingthisHandbookasuccess. Thanksalsoto ourpublicationadministratorMrsJ.Spurrforherusualdedicationand excellenceandtoKluwerAcademicPublishersfortheircontinuingsupport fortheHandbook. DovGabbay King'sCollegeLondon x Logic II IT Natural Program Artificialin- Logic p- language controlspec- telligence gramming processing ification, verification, concurrency Temporal Expressive Expressive Planning. Extension of logic poweroftense power for re- Time depen- Horn clause operators. currentevents. dent data. with time Temporal Specification Eventcalculus. capability. indices. Sepa- of tempo- Persistence Eventcalculus. rationofpast ral control. throughtime- Temporallogic fromfuture Decisionprob- the Frame programming. Problem.Tem- lems. Model checking. poral query language. temporal transactions. Modal logic. generalised Actionlogic Beliefrevision. Negation by Multi-modal quantifiers Inferential failure and logics databases modality Algorithmic Discourse rep- New logics. Generaltheory Proceduralap- proof resentation. Generic theo- of reasoning. proachtologic Direct com- remprovers Non-monotonic putation on systems linguisticinput Non- Resolving Loopchecking. Intrinsiclogical Negation by monotonic ambigui- Non-monotonic discipline for failure.Deduc- reasoning ties. Machine decisionsabout AI. Evolving tivedatabases translation. loops. Faults and com- Document insystems. municating classification. databases Relevance theory Probabilistic logicalanalysis Realtimesys- Expert sys- Semantics for and fuzzy oflanguage tems tems.Machine logicprograms logic learning Intuitionistic Quantifiers in Constructive Intuitionistic Horn clause logic logic reasoning and logicisabetter logic is really proof theory logical basis intuitionistic.