BEGIN:VCALENDAR METHOD:REQUEST PRODID:Microsoft Exchange Server 2010 VERSION:2.0 BEGIN:VTIMEZONE TZID:Pacific Standard Time BEGIN:STANDARD DTSTART:16010101T020000 TZOFFSETFROM:-0700 TZOFFSETTO:-0800 RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=1SU;BYMONTH=11 END:STANDARD BEGIN:DAYLIGHT DTSTART:16010101T020000 TZOFFSETFROM:-0800 TZOFFSETTO:-0700 RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=2SU;BYMONTH=3 END:DAYLIGHT END:VTIMEZONE BEGIN:VEVENT ORGANIZER;CN="Beesley, Lisa":mailto:[email protected] DESCRIPTION;LANGUAGE=en-US:A Double Session of the\nOCIE Seminar in the His tory and Philosophy\nof Mathematics and Logic\n\n\nPlease note the early s tart time (3 p.m.) for this double session.\n\nIterated modalities\nSpeake r:\nBrice Halimi\n\n(Université Paris Cité)\n\nFriday\, March 13\, 2026\ n3 - 4:30 p.m. (PST)\nKeck Center 153\nChapman University\n\nAlso in hybri d format on Zoom:\nhttps://chapman.zoom.us/j/99548174703<https://schmidcol legeofscienceandtechnology.cmail20.com/t/r-i-tkudjrc-l-y/>\nMeeting ID: 99 5 4817 4703\nPasscode: 000000\n\nAbstract:\n\nModal iteration is the super position of modal clauses\, as when some proposition is said to be\, for i nstance\, necessarily necessarily true. It has a very strong meaning: Sayi ng that a proposition is necessarily necessarily true amounts\, intuitivel y\, to saying that that proposition is necessarily true “whatever the ra nge of the possible itself may be.” In terms of possible worlds\, the la tter phrase implies that the collection of all possible worlds has itself many possible configurations\, corresponding to “second-order” possibl e worlds. The admissibility of iterated modalities is not self-evident at all and is a fundamental issue throughout the philosophical tradition\, wh ich deserves to be highlighted more than it has been so far. That will be my starting point.\n\nThen\, assuming the meaningfulness of iterated modal ities\, how to specify their semantics? In terms of possible worlds\, the semantic counterpart of modal iteration is a “change of scale\,” i.e.\ , the shift to ranges of possible worlds in the form of second-order possi ble worlds\, then to ranges of second-order possible worlds in the form of third-order possible worlds\, and so on. Such a progression thus refers t o higher-order possible worlds\, based on an open-ended collection of rang es of possible worlds lying at higher and higher levels\, in sharp contras t to the metaphysical single-levelness that Leibniz bestowed on his possib le worlds.\n\nI will argue that Kripke semantics for propositional modal l ogic remains too Leibnizian in that respect. I will thus put forward anoth er semantic framework\, geared to better formalizing modal change of scale and the concept of higher-order possible world. The ensuing modal semanti cs\, developed with tools coming from differential geometry\, aims to gene ralize Kripke semantics and to endow modal logic with a deepened geometric meaning.\n\nGödel's Incompleteness Theorems Beyond the Classical: LFIs a nd Provability Logic\nSpeaker:\nWalter Carnielli\n\n(Centre for Logic\, Ep istemology and the History of Science\, University of Campinas\, Brazil)\n \nFriday\, March 13\, 2026\n4:30 - 6 p.m. (PST)\nKeck Center 153\nChapman University\n\nAlso in hybrid format on Zoom:\nhttps://chapman.zoom.us/j/99 548174703<https://schmidcollegeofscienceandtechnology.cmail20.com/t/r-i-tk udjrc-l-j/>\nMeeting ID: 995 4817 4703\nPasscode: 000000\n\nAbstract:\n\nG ödel's Incompleteness Theorems rank among the deepest results in the foun dations of mathematics. Their classical proofs\, however\, rely on the Pri nciple of Explosion — a classical principle long regarded as logically h eavy-handed\, lacking both constructive force and logical relevance: it de rives anything whatsoever from a contradiction\, with no constructive just ification. This raises a natural question: are Gödel's results truly univ ersal\, or do they depend on the particular logic in which they are formul ated?\n\nThis talk investigates whether Gödel's theorems resist the press ure when classical logic is replaced by a more flexible framework: the Log ics of Formal Inconsistency (LFIs). Unlike classical logic\, LFIs allow co ntradictions to occur in a controlled\, local way without trivializing the whole system — by means of an explicit consistency operator that govern s when Explosion may be applied.\n\nWe show that both Incompleteness Theor ems can be reconstructed within this paraconsistent setting\, combined wit h tools from provability logic and modal logic. The price to pay is explic it: classical global assumptions must be replaced by careful local consist ency conditions. Once these are made transparent\, Gödel's arguments go t hrough.\n\nThe conclusion is philosophically significant: Gödel survives. Incompleteness is not an artifact of classical logic\, but a deep structu ral boundary of formal reasoning — one that persists even when consisten cy and contradiction are carefully pulled apart.\n\nThis is joint work wit h D\, Fuenmayor\, Bamberg\, Germany.\n\n\nThis seminar session will also c ount as a session of the MPP Seminar / Graduate Colloquium<https://schmidc ollegeofscienceandtechnology.cmail20.com/t/r-i-tkudjrc-l-t/>. The MPP Semi nar will also meet on Thursday\, March 12\, at 11:30am.\n\nFor more inform ation\, please contact Marco Panza ([email protected]) or Lisa Beesley (be [email protected]. See the complete OCIE Seminar Series calendar here<http s://www.chapman.edu/scst/graduate/ocie-seminar-series.aspx>.\n\n UID:040000008200E00074C5B7101A82E00800000000EAA9430B00B0DC01000000000000000 01000000082BBF1ADBE5EC945AD92F0B27560F8FD SUMMARY;LANGUAGE=en-US:OCIE Seminar Double Session: Brice Halimi and Walter Carnielli DTSTART;TZID=Pacific Standard Time:20260313T150000 DTEND;TZID=Pacific Standard Time:20260313T180000 CLASS:PUBLIC PRIORITY:5 DTSTAMP:20260309T200516Z TRANSP:OPAQUE STATUS:CONFIRMED SEQUENCE:0 LOCATION;LANGUAGE=en-US:KC 153 or Zoom X-MICROSOFT-CDO-APPT-SEQUENCE:0 X-MICROSOFT-CDO-OWNERAPPTID:2124631786 X-MICROSOFT-CDO-BUSYSTATUS:TENTATIVE X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY X-MICROSOFT-CDO-ALLDAYEVENT:FALSE X-MICROSOFT-CDO-IMPORTANCE:1 X-MICROSOFT-CDO-INSTTYPE:0 X-MICROSOFT-DONOTFORWARDMEETING:FALSE X-MICROSOFT-DISALLOW-COUNTER:FALSE X-MICROSOFT-REQUESTEDATTENDANCEMODE:DEFAULT X-MICROSOFT-ISRESPONSEREQUESTED:TRUE X-MICROSOFT-LOCATIONDISPLAYNAME:KC 153 or Zoom X-MICROSOFT-LOCATIONSOURCE:None X-MICROSOFT-LOCATIONS:[{"DisplayName":"KC 153 or Zoom"\,"LocationAnnotation ":""\,"LocationUri":""\,"LocationStreet":""\,"LocationCity":""\,"LocationS tate":""\,"LocationCountry":""\,"LocationPostalCode":""\,"LocationFullAddr ess":""}] BEGIN:VALARM DESCRIPTION:REMINDER TRIGGER;RELATED=START:-PT15M ACTION:DISPLAY END:VALARM END:VEVENT END:VCALENDAR
invite.ics
Description: application/ics
