简介:AsanimportantvariantofReiter'sdefaultlogic.Poole(1988)developedanonmonotonicreasoningframeworkintheclassicalfirst-orderlanguage,BrewkaandNebelextendedPoole'sapproachinordertoenablearepresentationofprioritiesbetweendefaults.Inthispaperageneralframeworkfordefaultreasoningispresented,whichcanbeviewedasageneralizationofthethreeapproachesabove.Itisprovedthatthesyntax-independentdefaultreasoninginthisframeworkisidenticaltothegeneralbeliefrevisionoperationintroducedbyZhangetal.(1997).Thisesultprovidesasolutiontotheproblemwhetherthereisacorrespondencebetweenbeliefrevisionanddefaultlogicfortheinfinitecase.Asaby-product,ananswertothethequestion,raisedbyMankinsonandGaerdenfors(1991),isalsogivenaboutwhetherthereisacounterpartcontracitoninnonmonotoniclogic.
简介:Inthispaperwestudytheone-dimensionalreflectedbackwardstochasticdifferentialequationswhicharedrivenbyBrownianmotionaswellasamutuallyindependentmartingaleappearinginadefaultablesetting.Usingapenalizationmethod,weprovetheexistenceanduniquenessofthesolutionstotheseequations.Asanapplication,weshowthatunderproperassumptionsthesolutionofthereflectedequationisthevalueoftherelatedmixedoptimalstopping-controlproblem.