Apologies for the late mailing this week.

Happy Thanksgiving to all,

Jonas Reitz

This Week in Logic at CUNY:

– – – – Monday, Nov 21, 2011 – – – –

– – – – Tuesday, Nov 22, 2011 – – – –

Computational Logic Seminar

Room C202. Time 2:00 – 4:00 PM. Note an unusual venue!

November 22.

Note an unusual day: Nov.22 (Tuesday) CUNY will follow the Thursday schedule, hence the change of venue.

There will be two one-hour talks.

Talk I, 2-3pm

Speaker: Robert Milnikel (Kenyon College)

Title: Embedding Answer Set Programming in Justification Logic Abstract: Answer Set Programming is a particular interpretation of logic programs with negation based on the Stable Model Semantics of M. Gelfond and V. Lifschitz. I will present a natural translation of finite propositional logic programs into the reflected fragment of the justification logic JD45 such that the JD45 models capture stable models of the original logic program. These are very preliminary results of a work in progress. No background in logic programming will be assumed, and relevant definitions and results of justification logic will be presented.

Talk II, 3-4pm

Speakers: Christian W. Bach and Andrés Perea (Maastricht University) Title: Utility Proportional Beliefs

Abstract: In game theory, basic solution concepts often conflict with experimental findings or intuitive reasoning. This fact is possibly due to the requirement that zero probability be assigned to irrational choices in these concepts. Here, we introduce the epistemic notion of common belief in utility proportional beliefs which also assigns positive probability to irrational choices, restricted however by the natural postulate that the probabilities should be proportional to the utilities the respective choices generate. Besides, we propose an algorithmic characterization of our epistemic concept. With regards to experimental findings common belief in utility proportional beliefs fares well in explaining observed behavior.

– – – – Wednesday, Nov 23, 2011 – – – –

– – – – Thursday, Nov 24, 2011 – – – –

*** CUNY Holiday ***

– – – – Friday, Nov 25, 2011 – – – –

*** CUNY Holiday ***

Next Week in Logic at CUNY:

– – – – Monday, Nov 28, 2011 – – – –

– – – – Tuesday, Nov 29, 2011 – – – –

– – – – Wednesday, Nov 30, 2011 – – – –

– – – – Thursday, Dec 1, 2011 – – – –

– – – – Friday, Dec 2, 2011 – – – –

Logic and Games Seminar

Friday, December 2, 2011 10:00 am GC, Room 3212

Professor Noson S. Yanofsky (Brooklyn College of the City University of New York)

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Set Theory Seminar

Friday, December 2, 2011 10:00 am GC 6417

Professor Victoria Gitman (NYC College of Technology (CUNY)) Forcing and gaps in 2^omega

Abstract. For a and b elements of 2^omega, we say that a is eventually dominated by b if a(n)<=b(n) for all but finitely many n. Consider a pair of sequences A={a_alpha|alpha < kappa} and B={b_beta|beta < lambda}, where a_alpha,b_beta are elements of2^omega and kappa,lambda are infinite regular cardinals. The pair (A,B) is called a

(kappa,lambda)-pregap if the a_alpha form an eventually dominating increasing sequence and the b_beta form an eventually dominating decreasing sequence, while each a_alpha is eventually dominated by each b_beta. A set c in 2^omega is said to separate a pregap (A,B) if it eventually dominates all a_alpha and is eventually dominated by all b_beta. A pregap (A,B) is called a gap if there is no such set c. Gaps have been studied since before the inception of set theory. In the late 1800’s Hadamard showed that there are no (omega,omega)-gaps and in the early 1900’s Hausdorff, who did much of the early work on gaps, showed that there is an (omega_1,omega_1)-gap. In this talk, we focus on the interaction between (omega_1,omega_1)-gaps and forcing. We shall consider the question of which gaps are destructible by omega_1-preserving forcing, that is, when we can add by forcing a set c separating the gap. Correspondingly, we shall consider the question of which gaps are indestructible by omega_1-preseving forcing and how we can force to make a gap indestructible in all further forcing extensions. For a more extensive abstract see

http://boolesrings.org/victoriagitman/2011/11/03/forcing-and-gaps-in-2omega/.

Model Theory Seminar

Friday, December 2, 2011 12:30 pm GC 6417

Mr. Manuel Alves (Ph.D. Program in Mathematics, Graduate Center of CUNY) Zilber’s trichotomy II

Logic Workshop

Friday, December 2, 2011 2:00 pm GC 6417

Dr. Janak Ramakrishnan (CMAF, University of Lisbon)

Interpretable groups are definable

Abstract. We present joint work with K. Peterzil and P. Eleftheriou that in an arbitrary o-minimal structure, every interpretable group is definably isomorphic to a definable one. Moreover, every definable group lives in a cartesian product of one-dimensional definable group-intervals (or one-dimensional definable groups).

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– – – – Web Site – – – –

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