Logic and Semantics Group


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Who We Are

We are an informal subgroup of the Lab for High-Assurance Software of the Dept. of Software Science of the Tallinn University of Technology (TUT).

We used to belong to the Institute of Cybernetics (IoC), a research institute that was closed 31 Dec 2016 in connection to a major reorganization of TUT. In the new organization, we were merged with the Formal Methods Group of the Dept. of Computer Science.

We pursue "Theory B": logic, semantics and theory of programming.

In the national evaluation exercise of ICT R&D 2009-2014, we were rated "excellent", which was the highest possible mark. Unfortunately, in the next exercise, assessing years 2018-2022, individual groups were not evaluated separately.

The current members of the group are:

Our current interns are

Our former members include:

As interns, we have in the past hosted:

Within the department, we collaborate closely with the Formal Methods Group of Jüri Vain and the Compositional Systems and Methods "TallCats" Group of Pawel Sobocinski.

Nationally, we collaborate with Vesal Vojdani's Software Technology Group at U. of Tartu's CS Department, including Danel Ahman (from Jan. 2024), and with Ülo Reimaa from the Algebra Group at their Math Department.

What We Do

We conduct research into a number of directions:

Check our list of publications.

We run a regular (almost weekly) research seminar, the Theory Seminar (TSEM).

We participated in the European FP6 IST project MOBIUS (2005-2009), the major proof-carrying code project of the Old World, and the FP7 ICT project HATS (2009-2013) on trustworthy highly adaptive software. We were part of the COST actions FoVeOOS (2008-2012) on verification of object-oriented software, Rich Model Toolkit (2009-2013), BETTY (2012-2016) on behavioral type systems, ARVI (2014-2018) on runtime verification and EUTYPES (2016-2020) on type theory and its applications, CERCIRAS (2020-2024) on resource-aware computing. We are part of EuroProofNet (2021-2025) on formal proofs.

At home, we were part of the Centre of Excellence in Computer Science (EXCS), which was one of the seven Estonian CoEs 2008-2015, and then Excellence in IT in Estonia (EXCITE), one of the nine Estonian CoEs 2016-2023. We ran the Coinduction project of the Estonian ICT research programme 2013-2015. Until the end of 2022, we benefited from the Estonian IT Academy research measure (2018-2023), the software trustworthiness theme.

Four of us are supported by an ETAG team grant (2021-2025) led by Pawel Sobocinski. Niccolò Veltri had a "bridging" ETAG starting grant for one year (2021) and won then a "proper" such (2022-2025, extended to 2026). Stephan Spahn had an ETAG postdoc grant (2021-2023) to work with us.

We were the organizing team behind all these international events that happened in Estonia: APPSEM 2004, AFP 2004, TFP/ICFP/GPCE 2005, IFIP WG 2.8 Meeting #22 (2005), MPC/AMAST 2006, EffTT 2007, NWPT 2008, COST FoVeOOS 2009 Winter School, ETAPS 2012, NWPT 2013, AIM XX (2014), TYPES 2015, Estonian-Finnish logic meeting of 2015, COST ARVI MC&WG meeting (2015), NWPT 2019, PPDP/LOPSTR 2021 and FSCD 2024.

We are active supporters of the annual EWSCS international winter schools in TCS and the (more or less) annual Estonian-Latvian CS Theory Days. The most recent editions were the Theory Days at Randivälja and EWSCS 2024. Coming up now is EWSCS 2025.

Since 2021 we have been organizing WLD Estonia events. The latest of those was the WLD 2025 Logic in Estonia Workshop.

We enjoy receiving guests. In 2023, we hosted Margus Veanes (Microsoft Research Redmond), Dylan McDermott (Reykjavik U.) (twice), Yasuaki Morita (Reykjavik U.) and Bryce Clarke (Inria). In 2024, we hosted Margus Veanes, Valentin Goranko, Jan von Plato, Giulio Fellin (U. di Verona), J.S. Lemay (Macquarie U.), Rory Lucyshyn-Wright (Brandon U.), Robin Cockett (U. of Calgary) and Keisuke Hoshino (Kyoto U.) visited.

We teach courses on programming languages, verification, algorithms and data structures and mathematics for computer science:

Interested in Working Here or Visiting?

If you are interested in doing a PhD with one of us, get in touch - there may be opportunities for this.

Also, if you would like to visit and give a seminar talk, email us.


We are proud to be supported by Zulip and grateful.


Tarmo Uustalu
Last update 1 February 2025