in preparation

Work on multiagent, collective belief and intention revision
Work on DEL-style updates on CGSs, with Rustam Galimullin, Maksim Gladyshev and Munyque Mittelmann
Work on applying quantitative temporal logics to Deep Reinforcement Learning, with Giovanni Varricchione and others
Coalgebraic Analysis of Social Systems, with Nina Otter and Emily Roff
Semipromonads and Unitalization

papers, talks & organized events

2024

IJCAI
Revising Beliefs and Intentions in Stochastic Environments

Nima Motamed, Natasha Alechina, Mehdi Dastani and Dragan Doder

In Proceedings of the Thirty-Third International Joint Conference on Artificial Intelligence, IJCAI-24

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The development of autonomous agents operating in dynamic and stochastic environments requires theories and models of how beliefs and intentions are revised while taking their interplay into account. In this paper, we initiate the study of belief and intention revision in stochastic environments, where an agent’s beliefs and intentions are specified in a decidable probabilistic temporal logic. We then provide general Katsuno & Mendelzon-style representation theorems for both belief and intention revision, giving clear semantic characterizations of revision methods.
@inproceedings{MotamedEtAl2024Revising, title = {Revising Beliefs and Intentions in Stochastic Environments}, author = {Motamed, Nima and Alechina, Natasha and Dastani, Mehdi and Doder, Dragan}, booktitle = {Proceedings of the Thirty-Third International Joint Conference on Artificial Intelligence, {IJCAI-24}}, publisher = {International Joint Conferences on Artificial Intelligence Organization}, editor = {Larson, Kate}, pages = {3513--3522}, year = {2024}, month = aug, note = {Main Track}, doi = {10.24963/ijcai.2024/389}, }
VvL Ess

Social Choice Essentials

Organized in May 2024, at University of Groningen in Groningen, The Netherlands.

Description URL

VvL Essentials talks are relatively high-level and broad overviews, that introduce early-career logicians (specifically PhDs) and logic-adjacent researchers to a field they may not be familiar with. This forms a low-threshold way to broaden their knowledge of the field at large, and encourages collaborations. The talks are hosted at different universities within the Netherlands.

This edition was on Social Choice Theory, with speaker Davide Grossi (University of Groningen). Abstract below:

In this lecture I will review some important contributions of social choice theory to our thinking about democracy, and the way we practice it: from classical results to more recent advances actively supporting contemporary democratic innovations.

2023

VvL Ess

Dynamic Epistemic Logic Essentials

Organized in Nov 2023, at Utrecht University in Utrecht, The Netherlands.

Description URL

VvL Essentials talks are relatively high-level and broad overviews, that introduce early-career logicians (specifically PhDs) and logic-adjacent researchers to a field they may not be familiar with. This forms a low-threshold way to broaden their knowledge of the field at large, and encourages collaborations. The talks are hosted at different universities within the Netherlands.

This edition was on Dynamic Epistemic Logic, with speaker Rustam Galimullin (University of Bergen). Abstract below:

Dynamic epistemic logic (DEL) is an umbrella term for a numerous family of formalisms for reasoning about how agents’ knowledge or beliefs change as a result of various epistemic actions. Such actions capture a plethora of scenarios: public and private announcements, observations, eavesdropping, etc. In the lecture, we will get acquainted with some of the classic DELs, flesh out some of the overarching patterns and intuitions in the field, and introduce foundational concepts and results. Moreover, we will survey the current state of the art and recent exciting research directions within DEL. For the lecture, I will not assume any familiarity with DEL or modal logics in general.
IJCAI
Probabilistic Temporal Logic for Reasoning about Bounded Policies

Nima Motamed, Natasha Alechina, Mehdi Dastani, Dragan Doder and Brian Logan

In Proceedings of the 32nd International Joint Conference on Artificial Intelligence (IJCAI-23)

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To build a theory of intention revision for agents operating in stochastic environments, we need a logic in which we can explicitly reason about their decision-making policies and those policies’ uncertain outcomes. Toward this end, we propose PLBP, a novel probabilistic temporal logic for Markov Decision Processes that allows us to reason about policies of bounded size. The logic is designed so that its expressive power is sufficient for the intended applications, whilst at the same time possessing strong computational properties. We prove that the satisfiability problem for our logic is decidable, and that its model checking problem is PSPACE-complete. This allows us to e.g. algorithmically verify whether an agent’s intentions are coherent, or whether a specific policy satisfies safety and/or liveness properties.
@inproceedings{MotamedEtAl2023bProbabilistic, author = {Motamed, Nima and Alechina, Natasha and Dastani, Mehdi and Doder, Dragan and Logan, Brian}, title = {Probabilistic Temporal Logic for Reasoning about Bounded Policies}, year = {2023}, month = aug, booktitle = {Proceedings of the 32nd International Joint Conference on Artificial Intelligence (IJCAI-23)}, editor = {Elkind, Edith}, pages = {3296--3303}, note = {Main Track}, doi = {10.24963/ijcai.2023/367}, }
DLPD

Dutch Logic PhD Day 2023

Organized in Jun 2023, at University of Groningen in Groningen, The Netherlands.

Description URL

Organized under the auspices of the VvL (The Dutch Association for Logic and Philosophy of the Exact Sciences), the Dutch Logic PhD Day 2023 is an event bringing together PhD students in Logic and related areas (Philosophy, Computer Science and AI) to foster exchanges of ideas and collaborations between young researchers from all over the Netherlands.

The Dutch Logic PhD Day 2023 will take place on June 23, 2023, at the University of Groningen. The event is planned as a full-day event, during which PhD students will have the possibility to present their research in the form of contributed talks. We invite the submission of works from any areas of Logic or related fields. Depending on the preference of the speaker, contributed talks can be shorter (15 minutes, including Q&A) or longer (30 minutes, including Q&A).

In addition to the contributed talks, there will be two invited talks. We are very happy to announce that the two invited speakers for this year’s event will be Natasha Alechina (Utrecht University) and Herman Geuvers (Radboud University).
ACLiC

Algebra, Categories and Logic in Computing: A Farsi-English Workshop

Organized in Jun 2023, in Saint-Erme-Outre-et-Ramecourt (Saint-Erme), France.

Description Poster URL

Algebra, category theory and logic have traditionally played an important role in our understanding of computing. Recently, there has been a surge in new ways of understanding how these disciplines can help in tackling old and new challenges in the theory and applications of computing, which include: combining machine learning and proof-theoretic approaches for compositional models of natural language; reasoning in and about multi-agent systems; developing languages and (compositional) models for programming, specifying and analysing systems and protocols.

The aim of this workshop is to bring together both leading and upcoming researchers who use such approaches, with the goal of promoting collaborations across the different disciplines.

This workshop is the first event in a program aimed at offering Farsi-speaking mathematicians — as well as any mathematician interested in building cross-cultural connections — opportunities to build a network and receive mentoring from leading Farsi-speaking mathematicians. The workshop will be held in a bilingual Farsi-English setting, and participants do not need to be fluent in both languages to attend.

Confirmed mentors for the event include Farhad Arbab (Centrum Wiskunde & Informatica, Amsterdam), Mehdi Dastani (Utrecht University) and Mehrnoosh Sadrzadeh (University College London).
AAAI-SSS

Probabilistic Temporal Logic for Reasoning about Bounded Policies

Talk at AAAI 2023 Spring Symposium On the Effectiveness of Temporal Logics on Finite Traces in AI, in Burlingame, California, USA (Online). Mar 2023

Slides URL
JMM

Extending Blockmodel Analysis to Higher-Order Models of Social Systems

Talk at Joint Mathematics Meetings 2023, in Boston, Massachusetts, USA. Jan 2023

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In network science, blockmodel analysis is an umbrella term that includes different methods and ideas for partitioning the set of nodes of a network into blocks of nodes that are similar. When networks are used to model social systems, these blocks correspond to the social positions of actors in the network. We discuss how to generalise blockmodel analysis to models that can take into account higher-order relations between social actors, such as simplicial complexes or hypergraphs. Using methods from universal coalgebra, we give a unifying framework for different types of equivalence relations used traditionally for the partitioning in blockmodel analysis, and we show how to perform the analysis within this new framework. Additionally, we give a coalgebraic generalisation of a result by Otter & Porter (2020) that relates blockmodel analysis with what is referred to within network science as role analysis. This generalisation allows us to instantiate the result for the higher-order structure we consider, and therefore relate specific variants of the two analyses for said structures. Finally, we discuss how our framework might accommodate approximate notions of equivalence, which are crucial for studying real-world systems.

2022

EUMAS
Participatory Budgeting with Multiple Resources

Nima Motamed, Arie Soeteman, Simon Rey and Ulle Endriss

In Proceedings of the 19th European Conference on Multi-Agent Systems (EUMAS 2022)

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We put forward a formal model of participatory budgeting where projects can incur costs with respect to several different resources, such as money, energy, or emission allowances. We generalise several well-known mechanisms from the usual single-resource setting to this multi-resource setting and analyse their algorithmic efficiency, the extent to which they are immune to strategic manipulation, and the degree of proportional representation they can guarantee. We also prove a general impossibility theorem establishing the incompatibility of proportionality and strategyproofness for this model.
@inproceedings{MotamedEtAl2022Participatory, author = {Motamed, Nima and Soeteman, Arie and Rey, Simon and Endriss, Ulle}, title = {Participatory Budgeting with Multiple Resources}, year = {2022}, month = sep, booktitle = {Proceedings of the 19th European Conference on Multi-Agent Systems (EUMAS 2022)}, pages = {330--347}, doi = {10.1007/978-3-031-20614-6_19}, editors = {Rothe, Jörg and Baumeister, Dorothea}, publisher = {Springer}, }
LAMAS & SR
A Probabilistic Finite Temporal Logic for Policies and Intentions

Nima Motamed, Natasha Alechina, Mehdi Dastani and Dragan Doder

In International Workshop on Logical Aspects in Multi-Agent Systems and Strategic Reasoning 2022 (LAMAS & SR 2022)

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We propose a new probabilistic temporal logic for Markov decision processes allowing us to reason about finite histories and policies. We comment on how the logic can express statements important for a theory of intention revision, show that it possesses the finite model property, and show that the model checking and satisfiability problems for the logic are both decidable.
@inproceedings{MotamedEtAl2022Probabilistic, author = {Motamed, Nima and Alechina, Natasha and Dastani, Mehdi and Doder, Dragan}, title = {A Probabilistic Finite Temporal Logic for Policies and Intentions}, year = {2022}, month = aug, booktitle = {International Workshop on Logical Aspects in Multi-Agent Systems and Strategic Reasoning 2022 (LAMAS & SR 2022)}, editors = {Mogavero, Fabio, and Pinchinat, Sophie}, }
AMS MRC

AMS Mathematics Research Communities 2022: Applied Category Theory

Participated in event, held in Jun 2022, in Java Center, NY, USA.

Description URL

Was one of the selected participants for the 2022 American Mathematical Society’s Mathematics Research Communities, for the topic of Applied Category Theory. This involved getting funded to attend a research meet with other participants, working on projects supervised by John Baez, Valeria de Paiva, and Nina Otter. I was on Nina Otter’s team, working on a study of social networks using simplicial complexes and categorical machinery.
CMCS
Boolean-Valued Multiagent Coalgebraic Logic

Alexander Kurz and Nima Motamed

In Short Contributions of the 16th IFIP WG 1.3 International Workshop on Coalgebraic Methods in Computer Science (CMCS 2022)

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We study coalgebraic generalisations of Fitting’s multiagent semantics of modal logic from his article "How True It Is = Who Says It’s True". First, we lift two-valued logics via distributive laws to multiagent logics on (co-)Kleisli categories, thus giving a category-theoretic account of Fitting’s notion of slicing. Second, we provide an alternative semantics where slicing is modelled in the functor instead of in the base category. Third, we extend our models to work with ordered sets of agents, and show that this enables the modelling of differences in expertise, certainty, and ability to achieve outcomes.
@inproceedings{KurzMotamed2022Boolean, author = {Kurz, Alexander and Motamed, Nima}, title = {Boolean-Valued Multiagent Coalgebraic Logic}, year = {2022}, month = apr, booktitle = {Short Contributions of the 16th IFIP WG 1.3 International Workshop on Coalgebraic Methods in Computer Science (CMCS 2022)}, editors = {Hansen, Helle Hvid and Zanasi, Fabio}, }

2021

MSc. Thesis
Multivalued Coalgebraic Modal Logic for Multiagent Systems and Multiplayer Games

Nima Motamed

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This thesis investigates coalgebraic generalizations of two multiagent modal logics from the literature, in which truth values are identified with sets of agents. In the first logic, which is due to Melvin Fitting, the truth value of a formula is identified as the set of agents for whom the formula is true, while in the second logic, which is due to Loes Olde Loohuis and Yde Venema, the truth value of a formula is identified as the set of players that have a winning strategy at a corresponding position in a multiplayer evaluation game. For the first logic, we identify a new base category of interest, from which the generalization comes forth naturally using the theory of coalgebraic modal logic, and give proofs of adequacy and expressivity. For the second logic, we define multiplayer evaluation games in which play proceeds nondeterministically, and use the well-known fact that predicate liftings induce transformations from coalgebras to neighbourhood frames. Finally, we prove that fragments of our generalizations are equiexpressive, and show how they can naturally describe situations with multiple agents.
@phdthesis{Motamed2021Thesis, author = {Motamed, Nima}, title = {Multivalued Coalgebraic Modal Logic for Multiagent Systems and Multiplayer Games}, school = {Institute for Logic, Language and Computation, University of Amsterdam}, year = {2021}, month = aug, address = {Amsterdam, The Netherlands}, type = {Master's thesis}, }

2020

CoSaQ

Quantifiers, Complexity, and Degrees of Universals: A Large-Scale Analysis

Talk at Cognitive Semantics and Quantities Seminar, held at the University of Amsterdam (Online). Oct 2020

2018

BSc. Thesis
A Performance Analysis of Filtering Methods Applied to WiFi-Based Position Reconstruction

Nima Motamed

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WiFi-based position reconstruction is becoming an increasingly important field of study, with applications in both ubiquitous computing and crowd analysis. Many approaches to this problem provide high accuracy at the cost of low ease of use, by often requiring either specialised hardware or costly offline phases. We compare and analyze the use of several filtering methods in order to increase the accuracy of a low-cost and out-of-the-box trilateration approach to WiFi-based position reconstruction, by applying the filtering methods to positions reconstructed from walks through the largest stadium in the Netherlands. The compared filtering methods consist of exponential filtering, Gaussian filters, Savitzky-Golay filters, median filters and Kalman filters, along with several variations. In addition to the performance comparison, we apply sensitivity analysis to the parameters of the methods, determining which are of most importance to resulting accuracy. We find that the median filter and some of its variations perform the best, improving upon the baseline accuracy by seven metres. Other high performers include the Gaussian and Savitzky-Golay filters, which like the median filter, are simple in their procedures and require few parameters.
@phdthesis{Motamed2018Thesis, author = {Motamed, Nima}, title = {A Performance Analysis of Filtering Methods Applied to WiFi-Based Position Reconstruction}, school = {University of Amsterdam}, year = {2018}, month = aug, address = {Amsterdam, The Netherlands}, type = {Bachelor's thesis}, }