12th Workshop on Logical and Semantic Frameworks with Applications (LSFA 2017)
23-24 September 2017 - Universidade de Brasília, Brazil

Logical and semantic frameworks are formal languages used to represent logics, languages and systems. These frameworks provide foundations for formal specification of systems and programming languages, supporting tool development and reasoning.

LSFA 2017 aims to be a forum for presenting and discussing work in progress, and therefore to provide feedback to authors on their preliminary research. The proceedings are produced after the meeting, so that authors can incorporate this feedback in the published papers.

LSFA 2017 will be a satellite event of the 26th International Conference on Automated Reasoning with Analytic Tableaux and Related Methods (Tableaux 2017), the 11th International Symposium on Frontiers of Combining Systems (FroCoS 2017) and the 8th International Conference on Interactive Theorem Proving (ITP 2017) to be held in Brasília, Brazil, between 25 and 29 September 2017.

Previous editions took place in Porto (2016), Natal (2015), Brasília (2014), São Paulo (2013), Rio de Janeiro (2012), Belo Horizonte (2011), Natal (2010), Brasília (2009), Salvador (2008), Ouro Preto (2007) and Natal (2006).

Topics of Interest

Topics of interest to this forum include, but are not limited to:

  • Automated deduction
  • Applications of logical and/or semantic frameworks
  • Computational and logical properties of semantic frameworks
  • Formal semantics of languages and systems
  • Implementation of logical and/or semantic frameworks
  • Lambda and combinatory calculi
  • Logical aspects of computational complexity
  • Logical frameworks
  • Process calculi
  • Proof theory
  • Semantic frameworks
  • Specification languages and meta-languages
  • Type theory

Submission and Publication

Contributions should be written in English and submitted in the form of full papers with a maximum of 16 pages including references or short papers with a maximum of 6 pages including references. Additional technical material can be provided in a clearly marked appendix which will be read by reviewers at their discretion. Contributions must also be unpublished and not submitted simultaneously for publication elsewhere. The papers should be prepared in LaTeX using the generic ENTCS package (http://www.entcs.org/prelim.html). The submission should be in the form of a PDF file uploaded to Easychair:


The workshop pre-proceedings, containing the reviewed extended abstracts, will be handed-out at workshop registration. After the workshop the authors of both full and short papers will be invited to submit full versions of their works for the post-proceedings to be published in ENTCS. At least one of the authors should register for the conference. Presentations should be in English.

Important dates

  • Submission: 21 June 2017 DEADLINE EXTENDED TO: 28 JUNE 2017
  • Notification: 21 July 2017
  • Final pre-proceedings version due: 11 August 2017
  • LSFA 2017: 23-24 September 2017

Invited speakers

  • Beniamino Accattoli - INRIA
    • (In)Efficiency and Reasonable Cost Models

      This talk is about time cost models for the lambda-calculus. To allow the definition of basic complexity classes such as P or EXP directly in the lambda-calculus, a cost models has to be reasonable, that is, polynomially related to the one of Turing machines. For the lambda-calculus the existence of an evaluation strategy whose number of steps is a reasonable cost model has been a long-standing open problem. Positive answers to special cases were known since 1995, but a solution for the general case has been provided only in 2014. The problem is peculiar because some of its aspects are somewhat counter-intuitive. The talk is devoted to explain the subtleties of this fundamental topic, and to survey the results obtained so far. The key point that is often misunderstood, and on which we will focus, is that being efficient and being reasonable are two unrelated properties of evaluation strategies.

  • Hélène Kirchner - INRIA
    • Strategic Port Graph Rewriting in Porgy, an Interactive Modelling Framework

      The Porgy framework is based on strategic port graph rewriting to design executable specifications of complex systems. A system is represented by an initial graph and a collection of graph rewrite rules, together with a user-defined strategy to control the application of rules. The traditional operators found in strategy languages for term rewriting have been adapted to deal with the more general setting of graph rewriting, and some new constructs have been included in the strategy language to deal with graph traversal and management of rewriting positions. The talk will describe and illustrate the main concepts underlying the Porgy framework through examples from biological systems and social networks.

  • Renate Schmidt - University of Manchester
    • Automated Forgetting and Uniform Interpolation for Description Logics

      Forgetting eliminates symbols from a knowledge base so that consequences over the remaining symbols in the signature are preserved. In logic the problem has been studied as the uniform interpolation problem, a notion related to the Craig interpolation problem, but stronger. In computer science the importance of forgetting can be found in the knowledge representation literature, specification refinement literature and the area of description logic-based ontology engineering. In ontology-based information processing, forgetting allows users to focus on specific parts of ontologies in order to create decompositions and restricted views for in depth analysis or sharing with other users. Forgetting is also useful for information hiding, explanation generation. semantic difference computation and ontology debugging. Because forgetting is an inherently difficult problem - it is much harder than standard reasoning (satisfiability testing) - and very few logics are known to be complete for forgetting (or have the uniform interpolation property), there has been insufficient research on the topic and few forgetting tools are available.

      In recent work we have developed practical methods for computing uniform interpolants for ontologies defined in expressive OWL language dialects. These can forget both concept and role symbols and can handle ontologies specified in description logics from ALC to extensions of ALC with role inclusions, transitive roles role inverse and number restrictions and ABox statements. Another strand of our research investigates and develops practical methods for semantic forgetting, which is stronger than uniform interpolation. These methods can perform concept and role forgetting for expressive description logics with number restrictions, nominals, role inclusions, role inverse, role conjunction and the top role. Experiments on a large number of ontologies from real-world applications have shown both methods are practical.

      This is joint work with Patrick Koopmann and Yizheng Zhao.


Program Committee

Organizing Committee

Created: 2017-07-20 Qui 21:35