Seminar in Logic and Games
Thursday, September 20, 2012, 1 PM to 2:30 PM, room 4421
Choosing Products in Social Networks
Krzysztof R. Apt (CWI and University of Amsterdam)
Abstract: Social networks have become a huge interdisciplinary
research area with
important links to sociology, economics, epidemiology, computer
science, and mathematics.
We introduce a new threshold model of social networks, in which the
nodes influenced by their neighbours can adopt one out of several
We study various algorithmic questions concerning these networks, for
example the problem of computing the minimum (resp. maximum) possible
spread of a product.
Also, using game-theoretic concepts, we analyze the consequences of
adopting products by the agents who form the network. In particular,
we prove that determining an existence of a (pure) Nash equilibrium is
We explain how these results can be used to analyze consequences
of the addition of new products to a social network. We show that in
some cases such an addition can permanently destroy market stability.
Based on joint works with Vangelis Markakis and Sunil Simon.
Friday, September 21, 2012 2:00 pm GC 6417
Professor Patricia Blanchette (Notre Dame University)
Logic and conceptual analysis in Frege
Abstract. Gottlob Frege understood logical entailment very differently
than did David Hilbert, and hence understood e.g. independence and
consistency in what now count as quite unorthodox ways. The purpose of
this talk is to explain the motivation for Frege’s conception, and to
investigate some of its implications for evaluating the importance of
e.g. the existence of models of theories, the completeness of
first-order logic, and related topics. I’ll argue that by coming to
understand Frege better, we gain a better understanding of the
historical trajectory that logic in fact followed, as contrasted with
the one that Frege would have pursued.
The New York Philosophical Logic Group
Tuesday, Sep 25, 2012
Speaker: Graham Priest (GC, CUNY)
Topic: Validity Curries
Time/Place: Tuesday Sept. 25, 7:15 p.m. to 9:15 p.m., 2nd floor seminar
room, NYU Philosophy Dept (5, Washington Place)
Brief Abstract: Curry Paradoxes involving truth and set-hood are well known.
Those who favour unrestricted truth predicates and abstraction principles,
have tended to solve the paradoxes by rejecting the principle of Contraction
for conditionals. Of late, paradoxes in the same family, but involving the
notion of validity, have been turning up; and it would appear that these
cannot be solved in this way. In this talk I will suggest how these may be
solved by deploying a sub-structural logic which rejects Contraction for