ILLC-LIRa February 2022

illc-lira@list.uva.nl

2 participants
10 discussions

LIRa Session: Louwe Kuijer (Thursday, 3 March 16:30)
by LIRa Seminar 25 Feb '22

25 Feb '22

Dear all, We will have our next LIRa session on Thursday, 3 March 16:30. Please use our recurring zoom link: https://uva-live.zoom.us/j/88142993494?pwd=d1BsQWR4T2UyK0Job29YNThjaGRkUT09 (Meeting ID: 881 4299 3494, Passcode: 352984) You can find the details of the talk below. Speaker: Louwe Kuijer (University of Liverpool) Date and Time: Thursday, March 3rd 2022, 16:30-18:00, Amsterdam time. Venue: online. Title: Doing the best I can. Abstract. A preference structure is a graph that indicates preferences between alternatives. These alternatives could be possible worlds, outcomes of an action, strategies in a game or something else entirely. The preferences, similarly, can mean many different things: a world might be preferred over another if it is more plausible, an outcome if it improves social welfare, and a strategy might be preferred over another strategy that it defeats. >From these preferences we can determine the set of "best" worlds, outcomes and strategies. Generally, one should believe the best worlds, strive to obtain the best outcomes and play the best strategies. As usual in deontic logic, we can then define a notion of obligation (to believe, bring about or play), where ϕ is obligatory, denoted B(ϕ) if all of the best alternatives satisfy ϕ (and thus it is impossible to satisfy the obligation to be "best'' without making ϕ true). This notion of obligation can be extended to a conditional one, B(ϕ|ψ), where ϕ is obligatory given ψ, by relativization. In other words, we restrict the preference structure to those alternatives that satisfy ψ, and check whether ϕ is true in all of the best alternatives in that structure. The properties of this conditional obligation operator depend on (1) exactly how we define what the "best" states in a preference structure are and (2) what properties the preference relation satisfies (e.g., transitive, total, anti-symmetric). In this talk, I will discuss characterizations of the conditional belief operator under various such assumptions. We will also consider one case where, despite searching for a long time, I did not manage to find a characterization: this turned out to be because such a characterization does not exist. Hope to see you there! The LIRa team

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LIRa session: Hannes Leitgeb (tomorrow, Thursday, 24 February 16:30)
by LIRa Seminar 23 Feb '22

23 Feb '22

Dear all, We will have our next LIRa session tomorrow, on Thursday, 24 February 16:30. Please use our recurring zoom link: https://uva-live.zoom.us/j/88142993494?pwd=d1BsQWR4T2UyK0Job29YNThjaGRkUT09 (Meeting ID: 881 4299 3494, Passcode: 352984) You can find the details of the talk below. Speaker: Hannes Leitgeb (LMU Munich) Date and Time: Thursday, February 24th 2022, 16:30-18:00, Amsterdam time. Venue: online. Title: A Finitistic Semantics for Mathematics Abstract. Is mathematics (arithmetic, analysis, set theory,...) committed to the existence of infinitely many objects? The aim of my talk will be to argue the answer is: No. For that purpose, I will introduce a new semantics ("role semantics“) according to which mathematical statements can be understood as having only finite ontological commitments. I will assess the semantics, show that its properties are similar to those of standard Tarskian semantics, and hence conclude that there is not much disadvantage in interpreting mathematics by the new semantics. At the same time, the finitistic role semantics does not come with any epistemological benefit: if anything, our epistemic access to finitistic models of mathematics is mediated by standard infinitary ones. Hope to see you there! The LIRa team

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LIRa session: Hannes Leitgeb (Thursday, 24 February 16:30)
by LIRa Seminar 18 Feb '22

18 Feb '22

Dear all, We will have our next LIRa session on Thursday, 24 February 16:30. Please use our recurring zoom link: https://uva-live.zoom.us/j/88142993494?pwd=d1BsQWR4T2UyK0Job29YNThjaGRkUT09 (Meeting ID: 881 4299 3494, Passcode: 352984) You can find the details of the talk below. Speaker: Hannes Leitgeb (LMU Munich) Date and Time: Thursday, February 24th 2022, 16:30-18:00, Amsterdam time. Venue: online. Title: A Finitistic Semantics for Mathematics Abstract. Is mathematics (arithmetic, analysis, set theory,...) committed to the existence of infinitely many objects? The aim of my talk will be to argue the answer is: No. For that purpose, I will introduce a new semantics ("role semantics“) according to which mathematical statements can be understood as having only finite ontological commitments. I will assess the semantics, show that its properties are similar to those of standard Tarskian semantics, and hence conclude that there is not much disadvantage in interpreting mathematics by the new semantics. At the same time, the finitistic role semantics does not come with any epistemological benefit: if anything, our epistemic access to finitistic models of mathematics is mediated by standard infinitary ones. Hope to see you there! The LIRa team

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LIRa Session: Torben Braüner (tomorrow, Thursday, 17 February 16:30)
by LIRa Seminar 16 Feb '22

16 Feb '22

Dear all, We will have our next LIRa session tomorrow, on Thursday, 17 February 16:30. Please use our recurring zoom link: https://uva-live.zoom.us/j/88142993494?pwd=d1BsQWR4T2UyK0Job29YNThjaGRkUT09 (Meeting ID: 881 4299 3494, Passcode: 352984) You can find the details of the talk below. Speaker: Torben Braüner (Roskilde University) Date and Time: Thursday, February 17th 2022, 16:30-18:00, Amsterdam time. Venue: online. Title: Understanding responses of people with ASD in diverse reasoning tasks: A formal study Abstract. Recent studies have shown that in some reasoning tasks people with Autism Spectrum Disorder (ASD) perform better than typically developing people. In this talk, I compare three such tasks, namely a syllogistic task, a decision-making task from behavioral economics, and a task from the heuristics and biases literature (the Linda task), the aim being to identify common structure as well as differences. In the terminology of David Marr's three levels of cognitive systems, the tasks show commonalities on the computational level in terms of the effect of contextual stimuli, though an in-depth analysis of such contexts provides certain distinguishing features in the algorithmic level. I also make some general remarks on the approach, so as to set the stage for further studies in the area which could provide a better understanding of the reasoning process of ASD individuals. Joint work with Aishwarya Ghosh (University of Utah, USA) and Sujata Ghosh (Indian Statistical Institute, Chennai, India). Hope to see you there! The LIRa team

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LIRa-related event: Humane Conversations with Katrin Schulz and Robert van Rooij
by LIRa Seminar 15 Feb '22

15 Feb '22

Dear all, The following virtual event might be of interest to the LIRa audience: This Friday, Feb 18, 14.00-15.00 (Amsterdam time), Anthia Solaki will be discussing "Stereotypes in Language & Computational Language Models" with Katrin Schulz and Robert van Rooij. You can find the details and the registration form here: https://humane-ai.nl/events_report/10-humane-conversation-stereotypes-in-la… The LIRa team

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LIRa Session: Torben Braüner (Thursday, 17 February 16:30)
by LIRa Seminar 11 Feb '22

11 Feb '22

Dear all, We will have our next LIRa session on Thursday, 17 February 16:30. Please use our recurring zoom link: https://uva-live.zoom.us/j/88142993494?pwd=d1BsQWR4T2UyK0Job29YNThjaGRkUT09 (Meeting ID: 881 4299 3494, Passcode: 352984) You can find the details of the talk below. Speaker: Torben Braüner (Roskilde University) Date and Time: Thursday, February 17th 2022, 16:30-18:00, Amsterdam time. Venue: online. Title: Understanding responses of people with ASD in diverse reasoning tasks: A formal study Abstract. Recent studies have shown that in some reasoning tasks people with Autism Spectrum Disorder (ASD) perform better than typically developing people. In this talk, I compare three such tasks, namely a syllogistic task, a decision-making task from behavioral economics, and a task from the heuristics and biases literature (the Linda task), the aim being to identify common structure as well as differences. In the terminology of David Marr's three levels of cognitive systems, the tasks show commonalities on the computational level in terms of the effect of contextual stimuli, though an in-depth analysis of such contexts provides certain distinguishing features in the algorithmic level. I also make some general remarks on the approach, so as to set the stage for further studies in the area which could provide a better understanding of the reasoning process of ASD individuals. Joint work with Aishwarya Ghosh (University of Utah, USA) and Sujata Ghosh (Indian Statistical Institute, Chennai, India). Hope to see you there! The LIRa team

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LIRa session: Salvador Mascarenhas (tomorrow, Thursday, 10 February 16:30)
by LIRa Seminar 09 Feb '22

09 Feb '22

Dear all, We will have our next LIRa session tomorrow, on Thursday, 10 February 16:30. Please use our recurring zoom link: https://uva-live.zoom.us/j/88142993494?pwd=d1BsQWR4T2UyK0Job29YNThjaGRkUT09 (Meeting ID: 881 4299 3494, Passcode: 352984) You can find the details of the talk below. Speaker: Salvador Mascarenhas (Institut Jean-Nicod, Department of Cognitive Studies, Ecole Normale Supérieure) Date and Time: Thursday, February 10th 2022, 16:30-18:00, Amsterdam time. Venue: online. Title: Question-answer dynamics and confirmation theory in reasoning with alternatives Abstract. Informally, confirmation-theoretic approaches to reasoning propose that humans often do not compute posterior probabilities, as the usual norms for rationality recommend, but instead ask themselves to what extent a piece of information (the evidence) supports a particular conclusion (the hypothesis). This family of theories yields our best accounts of the conjunction fallacy and related reasoning problems. Yet from an empirical standpoint, its full scope is still unknown: just how pervasive is this decision-making strategy in human inference making? Additionally, the computational-level justification for confirmation-theoretic reasoning is still an open question: why would humans deploy a mode of reasoning that so often fails to maximize the probability that the conclusions we draw are true? This talk tries to contribute to answering these two questions. I show that illusory inferences with alternatives, a broad paradigm of deductive fallacies, require confirmation-theoretic tools and cannot be accounted for within traditional deductive theories or with probabilistic theories that exclusively use posterior probabilities as the standard for rationality. Additionally, I present two experiments on the lawyers-and-engineers paradigm from Kahneman and Tversky (1973), showing that errors in variants of this probabilistic task also require confirmation-theoretic notions. One of the experiments applies a simplified version of Kahneman and Tversky's original paradigm to carefully normed materials, allowing for more fine-grained theory testing. The other is a visual version of the task, using ad hoc concepts where the underlying probabilistic distributions are completely transparent to participants. I then outline a theory that combines confirmation-theoretic tools with the erotetic theory of reasoning (Koralus and Mascarenhas, 2013, 2018), an account of naive deduction where question-answer dynamics are at the root of failures of reasoning in the cases at hand. I argue that confirmation-theoretic reasoning plausibly arises from the semantics and pragmatics of questions and answers, and I propose that this fact offers the beginning of an explanation for the pervasiveness of confirmation-theoretic reasoning. Hope to see you there! The LIRa team

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LIRa-related event: CELT2022: Connections between Epistemic Logic and Topology (Deadline Extended: February 14)
by LIRa Seminar 09 Feb '22

09 Feb '22

Dear all, We would like to draw your attention to the following LIRa-related event. - - - - - Call for Abstracts - Deadline Extended https://easychair.org/cfp/CELT2022 Haifa, Israel, July 31-August 1, 2022 Extended Submission deadline: February 14, 2022 The link between epistemic logic and topology has its roots, on the one hand, in the topological semantics of modal logic, and on the other hand, in the intimate relations between topology and concurrency, and between topology and distributed computing. Recent years have witnessed an explosion of new work in this area, from the development of more expressive logics capable of capturing fine topological structure, to the leveraging of topological tools to represent concepts such as observations, questions, and dependence relations, and encoding deep connections with distributed computing. The richness of this area has spawned a thriving, interdisciplinary research program with applications in learning theory, network epistemology, public and private communication, inquisitive semantics, philosophy of science, and knowledge representation in distributed computing, among others. This workshop aims at bringing together scholars working on various ways of connecting logic and topology to showcase a variety of recent developments and applications in the area, and to foster new research collaborations. The workshop will take place as a part of FLoC 2022<https://floc2022.org>—the Federated Logic Conference— in Haifa, Israel, affiliated with LICS<https://lics.siglog.org/lics22/>. Our workshop will be held in the 2-day, pre-FLoC workshop block (July 31st - August 1st). Invited Speakers: David Fernandez Duque (Ghent University, Belgium) Nina Gierasimczuk (Danish Techinal University) Eric Goubault (École Polytechnique, France) Sophia Knight (University of Minnesota Duluth, USA) Tamar Lando (Columbia University, USA) Jeremy Ledent (University of Strathclyde, UK) Susumu Nishimura (Kyoto University, Japan) Sonja Smets (University of Amsterdam, Netherlands) Submissions: We invite submissions for presentations. To apply, please submit an extended abstract of up to 3 pages (excluding bibliography) in PDF format. Abstracts should be submitted via EasyChair: https://easychair.org/conferences/?conf=celt2022 Important dates: • Extended Abstract submission: February 14th, 2022 • Notification for acceptance: March 7th, 2022 • Workshop: July 31st - August 1st, 2022 Organizers: Alexandru Baltag (ILLC, University of Amsterdam) Adam Bjorndahl (Carnegie Mellon University) Aybüke Özgün (ILLC, University of Amsterdam) Sergio Rajsbaum (Universidad Nacional Autónoma de México) - - - - - kind regards, The LIRa team

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LIRa session: Salvador Mascarenhas (Thursday, 10 February 16:30)
by LIRa Seminar 06 Feb '22

06 Feb '22

Dear all, We will have our next LIRa session on Thursday, 10 February 16:30. Please use our recurring zoom link: https://uva-live.zoom.us/j/88142993494?pwd=d1BsQWR4T2UyK0Job29YNThjaGRkUT09 (Meeting ID: 881 4299 3494, Passcode: 352984) You can find the details of the talk below. Speaker: Salvador Mascarenhas (Institut Jean-Nicod, Department of Cognitive Studies, Ecole Normale Supérieure) Date and Time: Thursday, February 10th 2022, 16:30-18:00, Amsterdam time. Venue: online. Title: Question-answer dynamics and confirmation theory in reasoning with alternatives Abstract. Informally, confirmation-theoretic approaches to reasoning propose that humans often do not compute posterior probabilities, as the usual norms for rationality recommend, but instead ask themselves to what extent a piece of information (the evidence) supports a particular conclusion (the hypothesis). This family of theories yields our best accounts of the conjunction fallacy and related reasoning problems. Yet from an empirical standpoint, its full scope is still unknown: just how pervasive is this decision-making strategy in human inference making? Additionally, the computational-level justification for confirmation-theoretic reasoning is still an open question: why would humans deploy a mode of reasoning that so often fails to maximize the probability that the conclusions we draw are true? This talk tries to contribute to answering these two questions. I show that illusory inferences with alternatives, a broad paradigm of deductive fallacies, require confirmation-theoretic tools and cannot be accounted for within traditional deductive theories or with probabilistic theories that exclusively use posterior probabilities as the standard for rationality. Additionally, I present two experiments on the lawyers-and-engineers paradigm from Kahneman and Tversky (1973), showing that errors in variants of this probabilistic task also require confirmation-theoretic notions. One of the experiments applies a simplified version of Kahneman and Tversky's original paradigm to carefully normed materials, allowing for more fine-grained theory testing. The other is a visual version of the task, using ad hoc concepts where the underlying probabilistic distributions are completely transparent to participants. I then outline a theory that combines confirmation-theoretic tools with the erotetic theory of reasoning (Koralus and Mascarenhas, 2013, 2018), an account of naive deduction where question-answer dynamics are at the root of failures of reasoning in the cases at hand. I argue that confirmation-theoretic reasoning plausibly arises from the semantics and pragmatics of questions and answers, and I propose that this fact offers the beginning of an explanation for the pervasiveness of confirmation-theoretic reasoning. Hope to see you there! The LIRa team

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LIRa session: Wesley Holliday (tomorrow, Thursday, 3 February 18:15)
by LIRa Seminar 02 Feb '22

02 Feb '22

Dear all, We will have our next LIRa session tomorrow, on Thursday, 3 February 18:15. Please use our recurring zoom link: https://uva-live.zoom.us/j/88142993494?pwd=d1BsQWR4T2UyK0Job29YNThjaGRkUT09 (Meeting ID: 881 4299 3494, Passcode: 352984) You can find the details of the talk below. Speaker: Wesley Holliday (University of California, Berkeley) NOTE THE UNUSUAL TIME! Date and Time: Thursday, February 3rd 2022, 18:15-19:45, Amsterdam time. Venue: online. Title: The Orthologic of Epistemic Modals Abstract. My talk will be based on a joint paper with Matthew Mandelkern (NYU), “The Orthologic of Epistemic Modals” (https://escholarship.org/uc/item/0ss5z8g3). Epistemic modals have peculiar logical features that are challenging to account for in a broadly classical framework. For instance, while a sentence of the form ‘p, but it might be that not p’ appears to be a contradiction, 'might not p' does not entail 'not p', which would follow in classical logic. Likewise, the classical laws of distributivity and disjunctive syllogism fail for epistemic modals. Existing attempts to account for these facts generally either under- or over-correct. Some theories predict that 'p and might not p', a so-called epistemic contradiction, is a contradiction only in an etiolated sense, under a notion of entailment that does not allow substitution of logical equivalents; these theories underpredict the infelicity of embedded epistemic contradictions. Other theories savage classical logic, eliminating not just rules that intuitively fail but also rules like non-contradiction, excluded middle, De Morgan’s laws, and disjunction introduction, which intuitively remain valid for epistemic modals. In our paper, we aim for a middle ground, developing a semantics and logic for epistemic modals that makes epistemic contradictions genuine contradictions and that invalidates distributivity and disjunctive syllogism but that otherwise preserves classical laws that intuitively remain valid. We start with an algebraic semantics, based on ortholattices instead of Boolean algebras, and then propose a more concrete possibility semantics, based on partial possibilities related by compatibility. Both semantics yield the same consequence relation, which we axiomatize. Then we show how to extend our semantics to explain parallel phenomena involving probabilities and conditionals. The goal throughout is to retain what is desirable about classical logic while accounting for the non-classicality of epistemic vocabulary. Hope to see you there! The LIRa team

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