{"id":2254,"date":"2014-03-19T17:19:15","date_gmt":"2014-03-19T17:19:15","guid":{"rendered":"http:\/\/www.illc.uva.nl\/lgc\/seminar\/?p=2254"},"modified":"2014-03-22T21:29:05","modified_gmt":"2014-03-22T21:29:05","slug":"logiciclira-session-francesca-poggiolesi","status":"publish","type":"post","link":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/2014\/03\/logiciclira-session-francesca-poggiolesi\/","title":{"rendered":"LogiCIC\/LIRa Session: Francesca Poggiolesi and Brian Hill"},"content":{"rendered":"

Please note that in February and March the LIRa seminar will be held on WEDNESDAYS at 4:30.<\/em><\/p>\n

On Wednesday, \u00a0March 26, <\/strong>we will have a joint LogiCIC\/LIRa session with two 35 minutes talks<\/strong> (with a short break in between) by\u00a0Francesca Poggiolesi <\/strong><\/strong>and Brian Hill<\/strong><\/strong>. Everyone is cordially invited!<\/p>\n

Speakers:\u00a0Francesca Poggiolesi <\/strong>(CNRS-CEPERC) and\u00a0Brian Hill <\/strong>(CNRS-GREGHEC)
\nDate and Time: Wednesday, March 26, 2014,\u00a016:30-18:00 <\/strong>(first talk: 16:30-17:10, second talk: 17:20-18:00)
\n<\/strong>Venue: Science Park 107, Room\u00a0F1.15<\/strong><\/p>\n

———————————————————————
\nSpeaker: Francesca Poggiolesi <\/strong>(CNRS-CEPERC)
\nTitle:\u00a0An alternative proof-theoretical approach to standard conditional logics<\/strong>
\nTime: 16:30 – 17:10
\nAbstract:
\nConditional logics, which have a long and venerable history [5, 2, 3], have\u00a0been introduced to capture counterfactual sentences, i.e. conditionals of the\u00a0form “if A were the case, then B would be the case”, where A is false. If we interpret counterfactuals as material implications, we have that all counterfactuals\u00a0are trivially true, and this is an unpleasant conclusion. By means of conditional\u00a0logics, on the other hand, we can give a different and meaningful interpretation\u00a0of counterfactual sentences.
\nThere are several different systems of conditional logics. Amongst them we\u00a0focus on the system CK and its standard extensions, namely CK + {ID, MP,\u00a0CS, CEM}. These systems have a simple and useful semantics. One just needs\u00a0to consider a set of possible worlds W<\/em>, and a selection function f<\/em>; for each world\u00a0i<\/em> and each formula A<\/em>, f<\/em> selects the set of worlds of W<\/em> which are closer<\/em> to i <\/em>given the information A<\/em>. Thus a counterfactual sentence A > B<\/em> is true at a\u00a0world i<\/em> if, and only if, B<\/em> is true at all those worlds that are closer to i<\/em> given the\u00a0information A<\/em>.
\nIn this talk we aim at presenting sequent calculi for the system CK and all of\u00a0its extensions. These calculi are based on and fully exploit the simple semantics\u00a0interpretation of such systems. Moreover, they are contraction-free, weakening-free and cut-free; finally, their logical rules are all invertible.\u00a0As far as we know\u00a0the only other sequent calculi that have been proposed for the system CK and\u00a0its extensions are those of Olivetti and al. [4] (sequent calculi for other systems\u00a0of conditional logics have been proposed by e.g. [1]). With respect to these\u00a0calculi the main differences consist in a lighter formalisms and simpler logical\u00a0rules to manipulate.
\nBy using the same technique adopted for the sequent calculi, we will also\u00a0briefly show how to construct natural deduction calculi for CK + {ID, MP, CS,\u00a0CEM}.
\nReferences
\n[1] Crocco, G. and Lamarre, P. On the connection between non-monotonic inference systems and conditional logics. In Proceedings of the 3rd International Conference on Principles of Knowledge. Representation and Reasoning<\/em>, B. Nebel\u00a0and E. Sandewall Ed., 565-571, 1992.
\n[2] Lewis, D. Counterfactuals<\/em>. Basil Blackwell, 1973.
\n[3] Nute, D. Topics in Conditional Logic<\/em>. Reidel, Dordrecht, 1980.
\n[4] Olivetti, N., Pozzato, G. L., and Schwind, C. B. A sequent calculus and a
\ntheorem prover for standard conditional logics, ACM Transactions on Computational Logic (TOCL) 8 : 557-590, 2007.
\n[5] Stalnaker, R. A theory of conditionals, American Philosophical Quarterly,\u00a0Monograph Series no.2, Blackwell, Oxford, 98-112, 1968.<\/p>\n

——————————————————————-<\/p>\n

Speaker:\u00a0Brian Hill <\/strong>(CNRS-GREGHEC)
\nTitle: <\/span>Confidence in Beliefs and Decision Making
\n<\/strong>Time: 17:20 – 18:00
\nAbstract:
\nThe standard representation of beliefs in decision theory and much of formal epistemology, by probability measures, is incapable of representing an agent’s confidence in his beliefs. However, as shall be argued in this talk, the agent’s confidence in his beliefs plays, and should play, a central role in many of the most difficult decisions which we find ourselves faced with. The aim of this talk is to formulate a representation of agents’ doxastic states and a (axiomatically grounded) theory of decision which recognises and incorporates confidence in belief. Time-permitting, consequences for decision in the face of radical uncertainty will be examined.<\/p>\n","protected":false},"excerpt":{"rendered":"

Please note that in February and March the LIRa seminar will be held on WEDNESDAYS at 4:30.
\nOn Wednesday, \u00a0March 26, we will have a joint LogiCIC\/LIRa session with two 35 minutes talks (with a short break in between) by\u00a0Francesca Poggiolesi and Brian Hill. Everyone is cordially invited!
\nSpeakers:\u00a0Francesca Poggiolesi (CNRS-CEPERC) and\u00a0Brian Hill (CNRS-GREGHEC)
\nDate and Time: Wednesday, […]<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-2254","post","type-post","status-publish","format-standard","hentry","category-events"],"_links":{"self":[{"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/posts\/2254","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/comments?post=2254"}],"version-history":[{"count":17,"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/posts\/2254\/revisions"}],"predecessor-version":[{"id":2258,"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/posts\/2254\/revisions\/2258"}],"wp:attachment":[{"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/media?parent=2254"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/categories?post=2254"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/projects.illc.uva.nl\/lgc\/seminar\/wp-json\/wp\/v2\/tags?post=2254"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}