Logic@GU
The Logic Group at the University of Gothenburg
Welcome to the webpage of the Logic group at the University of Gothenburg. Information about our research and activities can be found through the menu at the top. More detailed information about our research and activities can be found on the personal pages of group members and our homepage at the University of Gothenburg.
Our group holds a bi-weekly research seminar in Logic, the annual Lindström Lecture series and other events including workshops and an annual Gothenburg World Logic Day Pub Quiz. Together with Stockholm University, we organise the monthly Nordic Online Logic Seminar.
Announcements
| 20 Mar 2026 | Scandinavian Logic Symposium and Summer School, 17-23 August, 2026 |
|---|---|
| 20 Feb 2026 | GothCaT, a new seminar series on Categories and Types |
| 23 Dec 2025 | Congratulations to Gianluca Curzi on his promotion to docent (Associate Professor) |
| 12 Sep 2025 | The 2025 Lindström Lectures will be delivered by Jouko Väänänen |
| 4 Jan 2025 | Welcome Ivan Di Liberti who has joined the group as lecturer! |
Upcoming seminars and events
Licentiate Seminar
Orvar Lorimer-Olsson (FLoV)
Power Lifting Logics: An Algebraic Approach to Semantic Set Lifting
Public defence of Orvar Lorimer Olsson’s Licentiate thesis.
Opponent Assistant Professor Fan Yang, Utrecht University
Examiner Professor Graham E Leigh, Göteborgs universitet
Abstract
This thesis concerns semantic set-lifting procedures in logic, particularly plurivalence and team semantics. These are methods of constructing new logical semantics in terms of collections of semantic objects from an initial logical semantic (for the studied cases in terms of sets of truth values or teams of assignments respectively). By representing the underlying semantics in terms of algebraic structures we present versions of these set-lifting constructions in terms of power algebras [Brink, 1992], that is, algebras of subsets with pointwise operations in an underlying algebraic structure. Doing so, and by considering the classes of such algebras, we present versions of the set-lifting procedures that are independent of the semantic representation of the original logic.
This thesis includes three papers presenting applications of the power-algebra interpretation of set-lifting procedures in three different cases. Paper I presents two new syntactic categorisations of a family of eight logics called the FDE-family, previously categorised semantically by Priest. These categorisations are also extended to larger families of logics. Paper II describes Priest’s notion of plurivalence in terms of power matrices and shows that reiterating the plurivalent construction is logically equivalent to a single application. Paper III (joint work with Fredrik Engström) instead deals with team semantics, and presents the logic of team properties (LTP) as a natural algebraically defined abstract team-semantic extension of classical propositional logic. LTP is a team logic closed under substitution (a property that is missing for most logics with team semantics) and still expressive enough to encode many traditional team logics as axiomatisable syntactic fragments.
The thesis can be accessed via the Gothenburg University Library Archive at https://hdl.handle.net/2077/93583
Articles contained within the thesis
This thesis is a compilation of the following articles
- Paper I: Forthcoming in The Australasian Journal of Logic.
- Paper II: Published in Proceedings of the ESSLLI 2026 Student Session, available via: https://philpapers.org/rec/JOSPOT-2
- Paper III: Unpublished. Also available via: https://arxiv.org/abs/2303.14022.