AAL 2026

Conference

This meeting is sponsored by the Association for Symbolic Logic. Student ASL members may apply for (limited) ASL travel funds (see here). The requirement is strict that they must be members of the ASL in order to apply, and applications must be received three months prior to the start of the meeting. Shannon Miller, the ASL administrator, is a good source of information and answers.

The Australasian Association for Logic will hold its annual conference from Monday 9 November to Friday 13 November, 2026. The physical location will be the Victoria University of Wellington in Wellington, New Zealand. The conference aims to bring together logicians, either based in Australasia or with the desire to connect with logicians based in Australasia, working in mathematical, computational, or philosophical logic. The conference is intended to provide a platform for presentation and exchange of ideas. Thus, we invite contributions in all areas of logic, especially if you would like to advertise your best results to logicians outside your own subfield. We welcome published or unpublished work.

There will be eight one-hour invited talks on different logic topics. The speakers will be Rod Downey (Victoria University of Wellington), Ed Mares (Victoria University of Wellington), Rob Goldblatt (Victoria University of Wellington), Guillermo Badia (University of Queensland), Sasha Rubin (Sydney), Bakh M.Khoussainov (University of Electronic Science and Technology of China & The University of Auckland), Takayuki Kihara (Nagoya University), and Isabella Scott (University of Wisconsin-Madison).

Session times will be 30 minutes. The scheduling is done according to Brisbane local time (AEDT, UTC+10). Find your local time.

To register, please email aalwellington2026@gmail.com. The Zoom URLs for the talks (for those attending online), as well as the abstracts, will be sent to registered participants.

We invite submission of abstracts in any area of logic, broadly construed. To submit, send a short abstract (at most 300 words, i.e. about three quarters of a page in the standard, 11pt LaTeX article style, including the title, other heading material, and references) and title to aalwellington2026@gmail.com with the subject “AAL 2026”. Please use the template of the ASL (https://aslonline.org/rules-for-abstracts/) in your submission as abstracts by ASL members will be published in the Bulletin of Symbolic Logic. The soft deadline for submissions is 5 September. Submissions will be accepted for consideration until the hard deadline of Saturday, 20 September. Decisions will be sent out in late September. We would like to encourage submissions from members of groups that are underrepresented in logic.

The inaugural 'M.J. Cresswell Best Talk Award' will be given out to the most remarkable contributed (preferably student) paper at the conference. The prize committee will be formed by the organizers and the invited speakers. M.J. Cresswell (1939-2024) was a distinguished Australasian logician and a former president of the AAL.

Organising committee: Sasha Melnikov (Victoria University of Wellington, New Zealand; local organizer), Noam Greenberg (Victoria University of Wellington, New Zealand; local organizer), and Dan Turestky (Victoria University of Wellington, New Zealand; local organizer).

Steering committee: Zach Weber (Otago), Dan Turetsky (Victoria University of Wellington) and Shawn Standefer (North Carolina State).

The book of abstracts for the conference will be available at a suitable date.

Schedule

Invited Speakers

TBA

Rod Downey, Victoria University of Wellington, New Zealand.

Abstract

TBA

Ed Mares, Victoria University of Wellington, New Zealand.

Abstract

TBA

Tomasz Kowalski, Jagiellonian University, Poland.

Abstract

TBA

Containment of Conjunctive Queries with Negative information over Semirings

Guillermo Badia, University of Queensland, Australia.

Abstract

In this paper, we study the containment problem for (unions of) conjunctive queries ((U)CQs) with negative information on semiring-annotated databases. Our approach to negative information follows the treatment of negation proposed by Grädel and Tannen (2017, 2019, 2021 and 2024) for first-order logic and fixed point logic which applies productively to large classes of semirings, including bounded distributive lattices, as well as the important provenance semirings studied for positive CQ containment by Green (2009).

Negation features in (U)CQs along two dimensions: negated equalities (disequations), and negated relational atoms. We study complexity for each of them separately, as well as jointly. For disequations, we extend a methodology that proves the same complexity bounds (in the second level of the polynomial hierarchy) for our semirings of interest as the ones already known for the standard Boolean semiring. For CQs with negated relational atoms we show that the complexity, surprisingly, is the same as that of the containment of CQs without negation when one considers model-defining and provenance-tracking interpretations (namely, nondeterministic polynomial time). Interestingly, among bounded distributive lattices, the Boolean two-element case is the only one where the complexity of the problem continues to be hard for the second level of the polynomial hierarchy for model-defining interpretations. Furthermore, we show that the complexity increases again for distributive lattices if we focus on other classes of interpretations. Finally, we consider queries that have both negated equalities and negated relational atoms and show that the complexity of containment continues to be that of the case with just negated equalities.

This is joint work with Carles Noguera, Gaia Petreni, Alice Portone and Val Tannen.

TBA

Bakh M.Khoussainov, University of Electronic Science and Technology of China & The University of Auckland, China and New Zealand.