The Tenth Scandinavian Logic Symposium

The Tenth Scandinavian Logic Symposium (SLS 2018) was held at the University of Gothenburg, Sweden during June 11-13, 2018, under the auspices of the Scandinavian Logic Society. The previous two meetings of the SLS were held in Tampere, Finland (2014) and Roskilde, Denmark (2012).

The primary aim of the Symposium is to promote research in the field of logic (broadly conceived) carried out in research communities in Scandinavia. Moreover, it warmly invites participation of logicians from all over the world. The meeting will include invited lectures and a forum for participants to present contributed talks.

The scope of this event covers mathematical, computational, and philosophical logic. The major topics include (but are not limited to) the areas of Proof Theory, Constructivism, Model Theory, Set Theory, Computability Theory, Algebra and Logic, Categorical Logic, Logic and Computer Science, Logic and Linguistics, Logic in AI and Multi-Agent Systems, Logics of Games, Modal and other non-classical Logics, Axiomatic Theories of Truth, and Philosophical Logic.

We are proud to announce that the 2018 Lindström Lectures will be a part of SLS 2018 and delivered by Michael Rathjen. For more information see Lindström lectures webpage.

SLS 2018 is collocated with the Workshop on Dialogue and Perception 2018, June 14-15, 2018.

Important dates

• Abstract deadline: April 1, 2018 Extended to: April 8, 2018.
• Notification: April 20, 2018
• Early registration deadline: May 1, 2018
• Main event: June 11-13, 2018

Content

• Speakers
• Schedule
• Registration
• Submit an abstract
• Conference dinner
• Information and venue
• Organization and sponsors

Speakers

Invited speakers:

• Joel David Hamkins (CUNY): Set-theoretic potentialism and the universal finite set
  Providing a set-theoretic analogue of the universal algorithm, I shall define a certain finite set in set theory {x | φ(x)} and prove that it exhibits a universal extension property: it can be any desired particular finite set in the right set-theoretic universe and it can become successively any desired larger finite set in top-extensions of that universe. Specifically, ZFC proves the set is finite; the definition φ has complexity Σ₂ and therefore any instance of it φ(x) is locally verifiable inside any sufficiently large V~θ~; the set is empty in any transitive model; and if φ defines the set y in some countable model M of ZFC and y ⊂ z for some finite set z in M, then there is a top-extension of M to a model N of ZFC in which φ(x) defines the new set z. I shall draw out consequences of the universal finite set for set-theoretic potentialism and discuss several issues it raises in the philosophy of set theory.
  The talk will include joint work with W. Hugh Woodin, Øystein Linnebo and others. Questions and commentary concerning the talk can be made at: http://jdh.hamkins.org/set-theoretic-potentialism-sls-2018.

• Luke Ong (Oxford): Higher-order constrained Horn clauses and automatic program verification
  We introduce constrained Horn clauses in higher-order logic, and study satisfiability and related decision problems motivated by the automatic verification of higher-order programs. Although satisfiable systems of higher-order clauses in the standard semantics do not generally have least models, by viewing these systems as a kind of monotone logic programs, we show that there are non-standard semantics that do satisfy the least model property. Moreover the respective satisfiability problems in the standard and non-standard semantics are inter-reducible. With a view to exploiting the remarkable efficiency of SMT solvers, we survey recent developments in the algorithmic solution of higher-order Horn systems by reduction to first order, and discuss related problems.

• Michael Rathjen (Leeds) Public Lindström Lecture on Monday: Progressions of theories and slow consistency
  The fact that “natural” theories, i.e. theories which have something like an “idea” to them, are almost always linearly ordered with regard to logical strength has been called one of the great mysteries of the foundation of mathematics. Using paradoxical methods, e.g. self-reference Rosser-style, one can distill theories with incomparable logical strengths and show that the degree structure of logical strengths is dense in that between two theories S < T one can always find a third Q such that S < Q < T . But are there “natural” examples of such phenomena? We also know how to produce a stronger theory by adding the consistency of the theory. Can we get a stronger theory by adding something weaker than consistency that is still “natural”? These and other questions will be broached in the talk.

• Michael Rathjen (Leeds) Research Lindström Lecture on Wednesday: Bounds for the strength of the graph minor and the immersion theorem
  The graph minor theorem, GM, is arguably the most important theorem of graph theory. The strength of GM exceeds that of the standard classification systems of RM known as the “big five”. The plan is to survey the current knowledge about the strength of GM and other Kruskal-like principles, presenting lower and upper bounds.

• Katrin Tent (Münster): Ampleness in strongly minimal structures
  The notion of ampleness captures essential properties of projective spaces over fields. It is natural to ask whether any sufficiently ample strongly minimal set arises from an algebraically closed field. In this talk I will explain the question and survey recent results on ample strongly minimal structures.

The programme and book of abstracts is available as a pdf.

Schedule

The schedule for the symposium is available as a pdf.

Registration

To register please use the registration form. Please note that if a Swedish university is paying the registration fee you should not pay the VAT.

After you have registered you need to pay through the payment site. Please use the exact same name when paying as you used to register.

Early registration fees, applicable until 1st May, are:

• Regular fee (incl. VAT). 600 SEK
• Regular fee (excl. VAT). 480 SEK
• Student fee (incl. VAT). 400 SEK
• Student fee (excl. VAT). 320 SEK

Late fees will be announced later. If you need more information please contact the organisers.

Submit an abstract

Abstracts of contributed talks must be submitted as pdf files via EasyChair: https://easychair.org/conferences/?conf=sls2018

The abstracts should be prepared according to the ASL abstract guidelines: http://www.aslonline.org/rules_abstracts.html.

Upon notification of acceptance, authors will be requested to submit the LaTeX source files.

Conference dinner

The dinner will be held at Villa Belparc located in the beautiful park Slottskogen right by the Botanical Gardens.

• Dinner fee (incl. VAT). 700 SEK
• Dinner fee (excl. VAT). 600 SEK

Information and venue

The conference will be held at Eklandagatan 86, once the home of the Maths department and now housing the Department of History. It’s located close to Chalmers Johanneberg campus and a short bus trip (or a 20 minute walk) from Korsvägen – the first stop of the airport coaches.

We recommend the nearby located Quality Hotel Panorama.

Please see the map with the venue, hotel, lunch places and bus stops marked.

Organization and sponsors

Programme and organizing committee:

• Bahareh Afshari (co-chair)
• Rasmus Blanck
• Ali Enayat (co-chair)
• Fredrik Engström
• Martin Kaså
• Graham Leigh

For enquiries please email: sls2018 at flov.gu.se

Sponsors:

• Association for Symbolic Logic
• Department of Philosophy, Linguistics and Theory of Science (University of Gothenburg)
• Knut and Alice Wallenberg Foundation
• Wenner-Gren Stiftelserna