Dear all,
We will have our next LIRa session tomorrow, on Thursday, 6 October 16:30.
This will be a hybrid session. If you want to attend online, please use our recurring zoom link:
https://uva-live.zoom.us/j/89230639823?pwd=YWJuSnJmTDhXcWhmd1ZkeG5zb0o5UT09
(Meeting ID: 892 3063 9823, Passcode: 421723)
You can find the details of the talk below.
Speaker: Lingyuan Ye
Date and Time: Thursday, October 6th 2022, 16:30-18:00
Venue: F1.15 and online.
Title: Unification of Semantics of Modal Logic via Topological
Categories
Abstract. In this talk we will provide a unifying description of
different types of semantics of modal logic found in the literature,
via topological categories. In particular, we will show how the
natural extensions of basic modal logic, including multi-agency,
epistemic dependence, group agency, and logical dynamics, could be
naturally associated to various semantic structures within topological
categories. The unifying description and such correspondence would
allow us to generalise the interpretation of these extensions
simultaneously to any semantics of modal logic, and prove certain
structural results about them in the style of categorical logic.
Hope to see you there!
The LIRa team
Dear all,
We will have our next LIRa session on Thursday, 6 October 16:30.
This will be a hybrid session. If you want to attend online, please use our recurring zoom link:
https://uva-live.zoom.us/j/89230639823?pwd=YWJuSnJmTDhXcWhmd1ZkeG5zb0o5UT09
(Meeting ID: 892 3063 9823, Passcode: 421723)
You can find the details of the talk below.
Speaker: Lingyuan Ye
Date and Time: Thursday, October 6th 2022, 16:30-18:00
Venue: F1.15 and online.
Title: Unification of Semantics of Modal Logic via Topological Categories
Abstract. In this talk we will provide a unifying description of
different types of semantics of modal logic found in the literature,
via topological categories. In particular, we will show how the
natural extensions of basic modal logic, including multi-agency,
epistemic dependence, group agency, and logical dynamics, could be
naturally associated to various semantic structures within topological
categories. The unifying description and such correspondence would
allow us to generalise the interpretation of these extensions
simultaneously to any semantics of modal logic, and prove certain
structural results about them in the style of categorical logic.
Hope to see you there!
The LIRa team
Dear all,
We will have our next LIRa session tomorrow, on Thursday, 29 September 16:30.
This will be a hybrid session. If you want to attend online, please use our recurring zoom link:
https://uva-live.zoom.us/j/89230639823?pwd=YWJuSnJmTDhXcWhmd1ZkeG5zb0o5UT09
(Meeting ID: 892 3063 9823, Passcode: 421723)
You can find the details of the talk below.
Speaker: Thomas Randriamahazaka (University of St Andrews)
Date and Time: Thursday, September 29th 2022, 16:30-18:00
Venue: F1.15 and online.
Title: Aboutness and partiality: a duality-theoretic perspective.
Abstract. A familiar story identifies propositions with sets of
possible worlds. This can be understood as the semantic upshot of
Stone duality, once it is accepted that propositions form a Boolean
algebra. However, possible world semantics is often said to be too
coarse-grained to account for some semantic phenomena. To solve this
problem, it is possible to distinguish between two popular
hyperintensional strategies. The first one is to supplement the space
of possible worlds by a mereology of topics and to individuate
propositions as pairs consisting of a set of possible worlds and a
topic. The second one is to replace possible worlds by partial states.
The goal of this talk is to identify a bridge between these two
strategies using the tools of duality theory. From an algebraic point
of view, the first strategy can be seen as the application of the
construction known as Plonka sum. More precisely, the algebra of
propositions can be described as the Plonka sum of Boolean algebras
over the semilattice of topics. The main result of this talk is the
description of the topological dual of the Plonka sum construction,
dubbed co-Plonka sum. To do so, a new, weaker notion of topological
space will be needed. This dual construction will allow us to lift
Stone duality through the Plonka sum and have a description of the
dual space of the algebra of propositions. Just like the points of the
dual Stone space of a Boolean algebra can be understood as possible
worlds, the points of the dual space of the algebra of propositions
are best described as partial states, linking the first and the second
strategies.
Hope to see you there!
The LIRa team
Dear all,
We will have our next LIRa session on Thursday, 29 September 16:30.
This will be a hybrid session. If you want to attend online, please use our recurring zoom link:
https://uva-live.zoom.us/j/89230639823?pwd=YWJuSnJmTDhXcWhmd1ZkeG5zb0o5UT09
(Meeting ID: 892 3063 9823, Passcode: 421723)
You can find the details of the talk below.
Speaker: Thomas Randriamahazaka (University of St Andrews)
Date and Time: Thursday, September 29th 2022, 16:30-18:00
Venue: F1.15 and online.
Title: Aboutness and partiality: a duality-theoretic perspective.
Abstract. A familiar story identifies propositions with sets of
possible worlds. This can be understood as the semantic upshot of
Stone duality, once it is accepted that propositions form a Boolean
algebra. However, possible world semantics is often said to be too
coarse-grained to account for some semantic phenomena. To solve this
problem, it is possible to distinguish between two popular
hyperintensional strategies. The first one is to supplement the space
of possible worlds by a mereology of topics and to individuate
propositions as pairs consisting of a set of possible worlds and a
topic. The second one is to replace possible worlds by partial states.
The goal of this talk is to identify a bridge between these two
strategies using the tools of duality theory. From an algebraic point
of view, the first strategy can be seen as the application of the
construction known as Plonka sum. More precisely, the algebra of
propositions can be described as the Plonka sum of Boolean algebras
over the semilattice of topics. The main result of this talk is the
description of the topological dual of the Plonka sum construction,
dubbed co-Plonka sum. To do so, a new, weaker notion of topological
space will be needed. This dual construction will allow us to lift
Stone duality through the Plonka sum and have a description of the
dual space of the algebra of propositions. Just like the points of the
dual Stone space of a Boolean algebra can be understood as possible
worlds, the points of the dual space of the algebra of propositions
are best described as partial states, linking the first and the second
strategies.
Hope to see you there!
The LIRa team
Dear all,
We will have the first LIRa session of the new semester tomorrow, on Thursday, 15 September at 16:30.
This will be a hybrid session. If you want to attend online, please use our recurring zoom link:
https://uva-live.zoom.us/j/89230639823?pwd=YWJuSnJmTDhXcWhmd1ZkeG5zb0o5UT09
(Meeting ID: 892 3063 9823, Passcode: 421723)
You can find the details of the talk below.
Speaker: Zoé Christoff (University of Groningen)
Date and Time: Thursday, September 15th 2022, 16:30-18:00
Venue: room F1.15 at ILLC (NIKHEF building) and online / hybrid
Title: Reasoning about Cascading Ability in Social Networks
(joint work with Thomas Ågotnes)
Abstract. We propose a coalition logic to reason about the power of
influence of groups of agents in social networks. We focus on
threshold models, where agents are influenced into adopting a new
product or behaviour as soon as enough of their direct
network-neighbours have adopted it already. We introduce the syntax
and semantics and illustrate how it captures the ability of (groups
of) agents to trigger cascading effects in the network. We discuss
some properties featured by the new logic, some of which are directly
inherited from the underlying standard Coalition Logic, and some that
are novel.
Hope to see you there!
The LIRa team
Dear all,
Welcome back after the summer break!
We will start into the new academic year with our first LIRa session next week Thursday, 15 September at 16:30.
This will be a *hybrid* session. You are invited to join us on location, or you may attend online using this (new!) zoom link:
https://uva-live.zoom.us/j/89230639823?pwd=YWJuSnJmTDhXcWhmd1ZkeG5zb0o5UT09
(Meeting ID: 892 3063 9823, Passcode: 421723)
You can find the details of the talk below.
Speaker: Zoé Christoff (University of Groningen)
Date and Time: Thursday, September 15th 2022, 16:30-18:00
Venue: room F1.15 at ILLC (NIKHEF building) and online / hybrid
Title: Reasoning about Cascading Ability in Social Networks
(joint work with Thomas Ågotnes)
Abstract. We propose a coalition logic to reason about the power of
influence of groups of agents in social networks. We focus on
threshold models, where agents are influenced into adopting a new
product or behaviour as soon as enough of their direct
network-neighbours have adopted it already. We introduce the syntax
and semantics and illustrate how it captures the ability of (groups
of) agents to trigger cascading effects in the network. We discuss
some properties featured by the new logic, some of which are directly
inherited from the underlying standard Coalition Logic, and some that
are novel.
Hope to see you there!
The LIRa team
Dear all,
We will have our next LIRa session tomorrow, on Thursday, 30 June 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: Réka Markovich (University of Luxembourg)
Date and Time: Thursday, June 30th 2022, 16:30-18:00, Amsterdam time.
Venue: online.
Title: Multi-modal Logics for the Conceptual Analysis of Epistemic Rights
Abstract. The Deontic Logic for Epistemic Rights (DELIGHT) project
proposes to combine existing and develop new logics for reasoning
about epistemic rights as normative positions. In this talk, I
introduce the background theory of normative positions and the notion
of epistemic rights, and show how we have used different multi-modal
logics for the analysis of freedom of thought and the right to know.
Hope to see you there!
The LIRa team
Dear all,
We will have our next LIRa session on Thursday, 30 June 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: Réka Markovich (University of Luxembourg)
Date and Time: Thursday, June 30th 2022, 16:30-18:00, Amsterdam time.
Venue: online.
Title: Multi-modal Logics for the Conceptual Analysis of Epistemic Rights
Abstract. The Deontic Logic for Epistemic Rights (DELIGHT) project
proposes to combine existing and develop new logics for reasoning
about epistemic rights as normative positions. In this talk, I
introduce the background theory of normative positions and the notion
of epistemic rights, and show how we have used different multi-modal
logics for the analysis of freedom of thought and the right to know.
Hope to see you there!
The LIRa team
Dear all,
We will have our next LIRa session tomorrow, on Thursday, 23 June 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: Gaia Belardinelli (University of Copenhagen)
Date and Time: Thursday, June 23rd 2022, 16:30-18:00, Amsterdam time.
Venue: online.
Title: The dark side of knowledge: modeling implicit cognition in unawareness structures.
Abstract. There are different notions of implicit knowledge in
psychology, sociology, philosophy, logic, computer science, etc. A
common feature is that they refer to knowledge that lies in some
"dark" (non-explicit) level of awareness. Unawareness structures by
Heifetz et al. (2006, 2008) are event-based models featuring a
complete lattice of state-spaces. The spaces are used to represent
different awareness levels, which makes these structures naturally
suited to represent various implicit knowledge notions. Yet, so far,
unawareness structures only include a notion of explicit knowledge. In
this talk, we first show how to define implicit knowledge à la
Fagin-Halpern (1988) in unawareness structures, by deriving it from
explicit knowledge. Second, we use a notion of awareness bisimulation
contraction, based on awareness bisimulation by van Ditmarsch et al.
(2018), to construct an unawareness structure from a Fagin-Halpern '88
awareness model (and vice versa), and prove their formula equivalence
with respect to a language for implicit and explicit knowledge and
awareness. Third, we extend unawareness structures to include a notion
of tacit knowledge à la Polanyi (1962, 1966), and point at future
directions of this project, such as how to empirically identify and
thus reveal an agent's tacit knowledge from her actions, or how to
weaken the strong S5 notion of implicit knowledge to capture more
descriptive phenomena such as implicit biases. This is joint work with
Burkhard C. Schipper.
Hope to see you there!
The LIRa team
Dear all,
We will have our next LIRa session on Thursday, 23 June 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: Gaia Belardinelli (University of Copenhagen)
Date and Time: Thursday, June 23rd 2022, 16:30-18:00, Amsterdam
time.
Venue: online.
Title: The dark side of knowledge: modeling implicit cognition in unawareness structures.
Abstract. There are different notions of implicit knowledge in
psychology, sociology, philosophy, logic, computer science, etc. A
common feature is that they refer to knowledge that lies in some
"dark" (non-explicit) level of awareness. Unawareness structures by
Heifetz et al. (2006, 2008) are event-based models featuring a
complete lattice of state-spaces. The spaces are used to represent
different awareness levels, which makes these structures naturally
suited to represent various implicit knowledge notions. Yet, so far,
unawareness structures only include a notion of explicit knowledge. In
this talk, we first show how to define implicit knowledge à la
Fagin-Halpern (1988) in unawareness structures, by deriving it from
explicit knowledge. Second, we use a notion of awareness bisimulation
contraction, based on awareness bisimulation by van Ditmarsch et al.
(2018), to construct an unawareness structure from a Fagin-Halpern '88
awareness model (and vice versa), and prove their formula equivalence
with respect to a language for implicit and explicit knowledge and
awareness. Third, we extend unawareness structures to include a notion
of tacit knowledge à la Polanyi (1962, 1966), and point at future
directions of this project, such as how to empirically identify and
thus reveal an agent's tacit knowledge from her actions, or how to
weaken the strong S5 notion of implicit knowledge to capture more
descriptive phenomena such as implicit biases. This is joint work with
Burkhard C. Schipper.
Hope to see you there!
The LIRa team