BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250312T174502EDT-7861uNu8b6@132.216.98.100 DTSTAMP:20250312T214502Z DESCRIPTION:Bridging logic and constraint satisfaction with relational stru ctures and filters.\n\nWe investigate a correspondence between the complex ity hierarchy of constraint satisfaction problems and a hierarchy of logic al compactness hypotheses for finite relational structures. It seems that the harder a constraint satisfaction problem is\, the stronger the corresp onding compactness hypothesis is. At the top level\, the NP-complete const raint satisfaction problems correspond to compactness hypotheses that are equivalent to the ultrafilter axiom in all the cases we have investigated. At the bottom level\, the simplest constraint satisfaction problems corre spond to compactness hypotheses that are readily provable from the axioms of Zermelo and Fraenkel.\n \n This is joint work with Claude Tardif and Davi d Wehlau\, arXiv:1609.05221 [math.LO].\n DTSTART:20161104T193000Z DTEND:20161104T203000Z LOCATION:Room 1B23\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Danny Rorabaugh\, Queen'S University URL:/mathstat/channels/event/danny-rorabaugh-queens-un iversity-263866 END:VEVENT END:VCALENDAR