ILLC-LIRa June 2021

illc-lira@list.uva.nl

3 participants
8 discussions

CANCELLED: DIEP seminar by Alexandru Baltag
by LIRa Seminar 16 Jun '21

16 Jun '21

Dear all, Unfortunately the DIEP seminar by Alexndru Baltag that was scheduled for tomorrow (June 17th 11.00 am) is cancelled due to the heat wave. The talk will be rescheduled for September and will get back to you with the details in due time. Please note that it is *only* the DIEP seminar in the morning that is canceled and the weekly LIRa talk scheduled for tomorrow 15.00 (please note the unusual time!), will be held as planned. All the best, The LIRa team

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Tomorrow: DIEP talk (Alexandru Baltag) and LIRa Session *AT UNUSUAL TIME* (Cedegao Zhang)
by LIRa Seminar 16 Jun '21

16 Jun '21

Dear all, Tomorrow we will have two events of interest to the LIRa audience. The first is the DIEP talk of Alexandru Baltag, from 11:00 to 12:30. The second is our LIRa session with Cedegao Zhang, from 15:00 to 16:30 (please note the ***UNUSUAL TIME*** compared to our regular sessions!). You can find the details for both events, as well as their Zoom links, below. ----------------------------------------------------- *DIEP talk* Date and time: Thursday, June 17th 2021, 11:00-12:30, Amsterdam time. Speaker: Alexandru Baltag (UvA) Title: Group (Ir)Rationality: Can Logic help? Abstract: I present some applications of logical methods (in particular, of so-called dynamic epistemic logics) to the study of emergent phenomena in groups of `agents\\\', capable of reflection, communication, reasoning, argumentation etc.The main focus on the understanding of belief/preference formation and diffusion in social networks, and on how this affects the group\\\'s ``epistemic potential\\\": the ability of the agents to track the truth of the matter (with respect to some given relevant topic). While in some cases, ``wisdom of the crowds\\\" can increase the epistemic potential, in other situations the group\\\'s dynamics leads to informational distortions (-- the ``madness of the crowds\\\": cascades, ``groupthink\\\", the curse of the committee, pluralistic ignorance, group polarization, doxastic cycles etc). I explain how logic (in combination with probabilistic methods) can be used to provide some explanations for both types of situations, as well as to suggest some partial solutions to informational distortions. Zoom link: https://uva-live.zoom.us/j/85608909905 ---------------------------------------------------- *LIRa Session* Speaker: Cedegao Zhang (University of California, Berkeley) Date and Time: Thursday, June 17th 2021, 15:00-16:30, Amsterdam time. Title: A Computational Model of Higher-Order Epistemic Reasoning. Abstract. Reasoning about what other people know is an important cognitive ability, known as epistemic reasoning, which has fascinated psychologists, economists, and logicians. We propose a computational model of humans’ epistemic reasoning, including higher-order epistemic reasoning—reasoning about what one person knows about another person’s knowledge—that we test in an experiment using a deductive card game called “Aces and Eights”. Our starting point is the model of perfect higher-order epistemic reasoners given by the framework of dynamic epistemic logic. We modify this idealized model with bounds on the level of feasible epistemic reasoning and stochastic update of a player’s space of possibilities in response to new information. These modifications are crucial for explaining the variation in human performance across different participants and different games in the experiment. Our results demonstrate how research on epistemic logic and cognitive models can inform each other. This is a joint work with Ham Huang and Wesley Holliday. A preprint is available at https://psyarxiv.com/7hkzd/. Zoom link: https://uva-live.zoom.us/j/92907704256?pwd=anY3WkFmQVhLZGhjT2JXMlhjQVl1dz09 (Meeting ID: 929 0770 4256, Passcode: 036024) Hope to see you there! The LIRa team

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next week: DIEP talk (Alexandru Baltag) and LIRa session at *UNUSUAL TIME* (Cedegao Zhang)
by LIRa Seminar 12 Jun '21

12 Jun '21

Dear all, Next Thursday, June 17th, we have two events of interest to the LIRa audience. The first is the DIEP talk of Alexandru Baltag, from 11:00 to 12:30. The second is our LIRa session with Cedegao Zhang, which will take place at 15:00-16:30 (note the ***UNUSUAL TIME*** compared to our regular sessions!). You can find the details for both events, as well as their zoom links, below. ----------------------------------------------------- Date and time: Thursday, June 17th 2021, 11:00-12:30, Amsterdam time. Speaker: Alexandru Baltag (UvA) Title: Group (Ir)Rationality: Can Logic help? Abstract: I present some applications of logical methods (in particular, of so-called dynamic epistemic logics) to the study of emergent phenomena in groups of `agents\', capable of reflection, communication, reasoning, argumentation etc.The main focus on the understanding of belief/preference formation and diffusion in social networks, and on how this affects the group\'s ``epistemic potential\": the ability of the agents to track the truth of the matter (with respect to some given relevant topic). While in some cases, ``wisdom of the crowds\" can increase the epistemic potential, in other situations the group\'s dynamics leads to informational distortions (-- the ``madness of the crowds\": cascades, ``groupthink\", the curse of the committee, pluralistic ignorance, group polarization, doxastic cycles etc). I explain how logic (in combination with probabilistic methods) can be used to provide some explanations for both types of situations, as well as to suggest some partial solutions to informational distortions. Zoom link: https://uva-live.zoom.us/j/85608909905 ---------------------------------------------------- Speaker: Cedegao Zhang (University of California, Berkeley) Date and Time: Thursday, June 17th 2021, 15:00-16:30, Amsterdam time. Venue: online. Title: A Computational Model of Higher-Order Epistemic Reasoning. Abstract. Reasoning about what other people know is an important cognitive ability, known as epistemic reasoning, which has fascinated psychologists, economists, and logicians. We propose a computational model of humans’ epistemic reasoning, including higher-order epistemic reasoning—reasoning about what one person knows about another person’s knowledge—that we test in an experiment using a deductive card game called “Aces and Eights”. Our starting point is the model of perfect higher-order epistemic reasoners given by the framework of dynamic epistemic logic. We modify this idealized model with bounds on the level of feasible epistemic reasoning and stochastic update of a player’s space of possibilities in response to new information. These modifications are crucial for explaining the variation in human performance across different participants and different games in the experiment. Our results demonstrate how research on epistemic logic and cognitive models can inform each other. This is a joint work with Ham Huang and Wesley Holliday. A preprint is available at https://psyarxiv.com/7hkzd/. Recurring zoom link: https://uva-live.zoom.us/j/92907704256?pwd=anY3WkFmQVhLZGhjT2JXMlhjQVl1dz09 (Meeting ID: 929 0770 4256, Passcode: 036024) Hope to see you there! The LIRa team

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LIRa Session *today at 15:00*: Jiatu Li
by LIRa Seminar 10 Jun '21

10 Jun '21

Dear all, This is a reminder that our LIRa session with Jiatu Li today will take place at an UNUSUAL TIME, namely 15:00-16:30. You can find the details of the talk below. We will use our recurring zoom link: https://uva-live.zoom.us/j/92907704256?pwd=anY3WkFmQVhLZGhjT2JXMlhjQVl1dz09 (Meeting ID: 929 0770 4256, Passcode: 036024). Speaker: Jiatu Li Date and Time: Thursday, June 10th 2021, 15:00-16:30, Amsterdam time. Venue: online. Title: Formalization of PAL in Lean. Abstract. Proof assistant (or theorem prover) is a useful tool to organize and check formal mathematical proofs. Despite of several impressive stories, it still seems hopeless for common mathematicians to use it for their daily work. However, it may be handy for logicians in some certain applications, for example, in developing proof systems. In this talk, we will demonstrate a formalization of public announcement logic (including syntax, semantics, a proof system and meta-theorems including soundness and completeness) in Lean theorem prover. We will also discuss in general the potential applications of proof assistant in logic research. Hope to see you there! The LIRa team

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tomorrow: DIEP talk (Casper van Elteren) and LIRa session at *unsual time* (Jiatu Li)
by LIRa Seminar 09 Jun '21

09 Jun '21

Dear all, Tomorrow, June 10th, we have two events of interest to the LIRa audience. The first is the DIEP talk of Casper van Elteren, from 11:00 to 12:30. The second is our LIRa session with Jiatu Li, which will take place on 15:00-16:30 (note the UNUSUAL TIME compared to our regular sessions!). You can find the details for both events, as well as their zoom links, below. ----------------------------------------------------- Date and time: Thursday, June 10th 2021, 11:00-12:30, Amsterdam time. Speaker: Casper van Elteren (UvA) Title: Through the looking glass - Information flows in complex systems Abstract: Understanding dynamical systems is a fundamental problem for the 21st century. Despite the prima facie differences and purposes of many real-world networks, previous research shows several universal characteristics in networks properties such as the small-world phenomenon, fat-tail degree and feedback loops. This has led to the common but often implicit assumption that the connectedness of a node in the network is proportional to its dynamic importance. For example in epidemic research, high degree nodes or \\\"super-spreaders\\\" are associated to dominant epidemic risk and therefore deserve special attention. Yet prior research shows that the shared universality in network characteristics is not shared in the dynamic or functional properties of many real-world systems. In this talk I will explore the relation between local interactions and macroscopic properties of a system through the lens of statistical physics and information theory. In particular, I will show novel methods on determining the so-called driver node in complex systems, and how tipping points can be studied from an information theoretical perspective. (website + slides: https://cvanelteren.github.io/talk/diep2021/) Zoom link: https://uva-live.zoom.us/j/85608909905 ----------------------------------------------------- Speaker: Jiatu Li Date and Time: Thursday, June 10th 2021, 15:00-16:30, Amsterdam time. Venue: online. Title: Formalization of PAL in Lean. Abstract. Proof assistant (or theorem prover) is a useful tool to organize and check formal mathematical proofs. Despite of several impressive stories, it still seems hopeless for common mathematicians to use it for their daily work. However, it may be handy for logicians in some certain applications, for example, in developing proof systems. In this talk, we will demonstrate a formalization of public announcement logic (including syntax, semantics, a proof system and meta-theorems including soundness and completeness) in Lean theorem prover. We will also discuss in general the potential applications of proof assistant in logic research. Recurring zoom link: https://uva-live.zoom.us/j/92907704256?pwd=anY3WkFmQVhLZGhjT2JXMlhjQVl1dz09 (Meeting ID: 929 0770 4256, Passcode: 036024) Hope to see you there! The LIRa team

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next week: DIEP talk (Casper van Elteren) and LIRa session at *unsual time* (Jiatu Li)
by LIRa Seminar 04 Jun '21

04 Jun '21

Dear all, Next Thursday, June 10th, we have two events of interest to the LIRa audience. The first is the DIEP talk of Casper van Elteren, from 11:00 to 12:30. The second is our LIRa session with Jiatu Li, which will take place on 15:00-16:30 (note the UNUSUAL TIME compared to our regular sessions!). You can find the details for both events, as well as their zoom links, below. ----------------------------------------------------- Date and time: Thursday, June 10th 2021, 11:00-12:30, Amsterdam time. Speaker: Casper van Elteren (UvA) Title: Through the looking glass - Information flows in complex systems Abstract: Understanding dynamical systems is a fundamental problem for the 21st century. Despite the prima facie differences and purposes of many real-world networks, previous research shows several universal characteristics in networks properties such as the small-world phenomenon, fat-tail degree and feedback loops. This has led to the common but often implicit assumption that the connectedness of a node in the network is proportional to its dynamic importance. For example in epidemic research, high degree nodes or \"super-spreaders\" are associated to dominant epidemic risk and therefore deserve special attention. Yet prior research shows that the shared universality in network characteristics is not shared in the dynamic or functional properties of many real-world systems. In this talk I will explore the relation between local interactions and macroscopic properties of a system through the lens of statistical physics and information theory. In particular, I will show novel methods on determining the so-called driver node in complex systems, and how tipping points can be studied from an information theoretical perspective. (website + slides: https://cvanelteren.github.io/talk/diep2021/) Zoom link: https://uva-live.zoom.us/j/85608909905 ----------------------------------------------------- Speaker: Jiatu Li Date and Time: Thursday, June 10th 2021, 15:00-16:30, Amsterdam time. Venue: online. Title: Formalization of PAL in Lean. Abstract. Proof assistant (or theorem prover) is a useful tool to organize and check formal mathematical proofs. Despite of several impressive stories, it still seems hopeless for common mathematicians to use it for their daily work. However, it may be handy for logicians in some certain applications, for example, in developing proof systems. In this talk, we will demonstrate a formalization of public announcement logic (including syntax, semantics, a proof system and meta-theorems including soundness and completeness) in Lean theorem prover. We will also discuss in general the potential applications of proof assistant in logic research. Recurring zoom link: https://uva-live.zoom.us/j/92907704256?pwd=anY3WkFmQVhLZGhjT2JXMlhjQVl1dz09 (Meeting ID: 929 0770 4256, Passcode: 036024) Hope to see you there! The LIRa team

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tomorrow: DIEP talk (Velimir Ilić) and regular LIRa session (Guillermo Menéndez Turata)
by LIRa Seminar 02 Jun '21

02 Jun '21

Dear all, Tomorrow, June 3rd, we have two events of interest to the LIRa audience. The first is the DIEP talk of Velimir Ilić, from 11:00 to 12:30. The second is our regular LIRa session with Guillermo Menéndez Turata, from 16:30 to 18:00. You can find the details for both events, as well as their zoom links, below. ----------------------------------------------------- Date and time: Thursday, June 3rd 2021, 11:00-12:30, Amsterdam time. Speaker: Velimir Ilić (Mathematical Institute of the Serbian Academy of Sciences and Arts) Title: An overview and characterization of generalized information measures Abstract: The aim of this talk is to present a comprehensive classification of the main entropic forms introduced in the last fifty years within statistical physics and information theory and to review the fundamental questions about the meaning of information. I will particularly focus on axiomatic approaches to the characterization of various generalizations of the Shannon entropy, such as the Rényi, the Tsallis, the Sharma-Mittal, and the Sharma-Mittal-Taneja entropies, as well as the more general classes of pseudo-additive entropies with a well-defined mathematical and information theoretic structure. Finally, I will point out possible applications of these measures in communication theory, statistical inference and complex systems modeling. Zoom link: https://uva-live.zoom.us/j/85608909905 ----------------------------------------------------- Speaker: Guillermo Menéndez Turata Date and Time: Thursday, June 3rd 2021, 16:30-18:00, Amsterdam time. Venue: online. Title: Uniform interpolation from cyclic proofs: the case of modal mu-calculus. Abstract. Uniform interpolation was first established for the modal mu-calculus by D’Agostino and Hollenberg via a combination of semantic and syntactic methods. A natural question is whether a purely syntactical proof of this result, in the style of Pitt’s seminal work on uniform interpolation for intuitionistic logic, can be produced. One possible reason Pitt’s method has not been applied to the modal mu-calculus is that it requires a setting where uniform interpolation can be proved by induction on cut-free derivations in a finitary system. While it is feasible to design cut-free calculi for fixpoint modal logics, they are often infinitary, i.e., derivations may have infinite branches. In this talk we apply Pitt’s technique to the modal mu-calculus and show how to construct uniform interpolants from cyclic derivations in an annotated goal-oriented proof system introduced by Jungteerapanich and Stirling. Recurring zoom link: https://uva-live.zoom.us/j/92907704256?pwd=anY3WkFmQVhLZGhjT2JXMlhjQVl1dz09 (Meeting ID: 929 0770 4256, Passcode: 036024) Hope to see you there! The LIRa team

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LIRa-related event next week: LoC conference
by LIRa Seminar 01 Jun '21

01 Jun '21

Dear all, Apart from our regular LIRa talks and the DIEP talk advertised earlier, we would like to bring to your attention the Logic of Conceivability Conference, scheduled for 7th-9th of June. You can find the details of the conference and the registration below. -------------------------------- The ability to think about non-actual possibilities is crucial for rational decision and action. When deciding what to do in situations of uncertainty or risk, we use our powers of imagination and conception to surveil the ways the world might be for all we know, and ponder the possible consequences of our actions. What is the logic of conceivability? Do thinking and imagining exhibit sufficient structure so to be amenable to precise modeling? Under what conditions does an imaginative episode establish a non-actual scenario as a real possibility? What are the special features of thought, talk and knowledge about mere possibility and conditionality? The aim of this conference, organized by the members of the Logic of Conceivability project, is to facilitate the conversation on these questions by bringing together both senior and rising young researchers from around the world. Date: June 7th – June 9th, 2021. Venue: online. Confirmed Speakers: Magdalena Balcerak Jackson (University of Miami); Ruth Byrne (Trinity College Dublin); Thomas Ferguson Peter Hawke (Lingnan University); Karolina Krzyżanowska (ILLC, University of Amsterdam / Arché, University of St. Andrews); Emiliano Lorini (CNRS, Université Paul Sabatier); Aybüke Özgün (ILLC, University of Amsterdam); Graham Priest (CUNY); Eva Rafetseder (University of Stirling); Sonia Roca Royes (University of Stirling); Tom Schoonen (ILLC, University of Amsterdam); Sonja Smets (ILLC, University of Amsterdam); Anthi Solaki (ILLC, University of Amsterdam); and Rineke Verbrugge (ALICE, University of Groningen). Attendance is free, but registration is required. Please check the conference website for more information: http://projects.illc.uva.nl/conceivability/LoC-Conference/ The LIRa team

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ILLC-LIRa June 2021