Cascais Miragem
33rd International Symposium on
Logic-based Program Synthesis and Transformation
October 23-24, 2023 - Cascais, Lisbon, Portugal
Co-located with PPDP 2023 as part of SPLASH 2023

Latest News

  • The recipients of the Best Paper Awards are:
    • Constrained Horn Clauses Satisfiability via Catamorphic Abstractions by Emanuele De Angelis, Fabio Fioravanti, Alberto Pettorossi and Maurizio Proietti (Regular Paper category)
    • Towards a Certified Proof Checker for Deep Neural Network Verification by Remi Desmartin, Omri Isac, Grant Passmore, Kathrin Stark, Guy Katz and Ekaterina Komendantskaya (Short Paper category)
  • The conference proceedings can be accessed at this link.
  • The complete SPLASH program is available.
  • Virtual registration is available as well.
  • Program is now available.
  • Invited speakers announced.
  • Registration is now open, early registration until 22 Sept.
  • Submission deadline extended until 9 June 2023 (AoE)
  • Submission open at https://easychair.org/conferences/?conf=lopstr2023.
  • Selected papers will be invited to the Journal of Theory and Practice of Logic Programming (TPLP).
  • All accepted papers will be incorporated into the conference proceedings and published by Springer as a volume in Lecture Notes in Computer Science (LNCS).
  • Program Committee announced.
  • The call for paper is out.


You can access the conference proceedings here. The free access for the conference participants will be granted until 17th of November (for 4 weeks).


(Virtual) Registration for LOPSTR 2023 is available through the SPLASH 2023 website.

Invited Speakers

Maribel Fernandez , King's College London, UK (Jointly with PPDP and sponsored by ALP).
Title: Unification Modulo Equational Theories in Languages with Binding Operators
Abtract: Unification (i.e., solving equations between terms) is a key step in the implementation of logic programming languages and theorem provers, and is also used in type inference algorithms for functional languages and as a mechanism to analyse rewrite-based specifications (e.g., to find critical pairs). Matching is a version of unification in which only one of the terms in the equation can be instantiated.
Often, operators satisfy equational axioms (e.g., associativity, commutativity), which must be taken into account during the unification or matching process. In addition, when the expressions to be unified involve binding operators (as is the case when representing programs, logics, computation models, etc.), unification and matching algorithms must take into account the alpha-equivalence relation generated by the binders.
In this talk, we present matching and unification algorithms for languages that include binding operators as well as operators that satisfy equational axioms, such as associativity and commutativity.
Manuel Hermenegildo , IMDEA Software Institute and Universidad Politecnica de Madrid, Spain (sponsored by ALP).
Title: On-The-Fly Verification via Incremental, Interactive Abstract Interpretation with CiaoPP and VeriFly
Abtract: Ciao Prolog pioneered the idea of being able to optionally and gradually add assertions or contracts to programs in order to offer formal guarantees, a now very popular solution for solving the classic trade-offs between dynamic and static languages. This approach is enabled by Ciao’s program analysis and verification framework, CiaoPP, which performs abstract interpretation-based, context- and path-sensitive analysis to infer information against which assertions are checked to achieve verification or flag errors statically. The framework supports multiple other languages in addition to Prolog, from machine code to smart contracts, by translation into Horn clauses. Program semantics is computed over different user-definable abstract domains, via efficient fixpoint computation. This allows inference and verification of both functional and non-functional properties, including, e.g., energy or ’gas’ consumption.
While this type of verification can be performed offline (e.g., as part of con- tinuous integration) it is very useful when it occurs interactively during software development, flagging errors as the program is written. However, while context- and path-sensitive global analysis over complex domains can provide the preci- sion needed for effective verification and optimization, it can also be expensive when applied to large code bases, sometimes making interactive use impracti- cal. On the other hand, in many program development situations modifications are small and isolated within a few components. The modular and incremental fixpoint algorithms used by CiaoPP take advantage of this to reuse as much as possible previous analysis results, reducing response times in interactive use.
In this talk we will review these ideas and show how the integration of the Ciao abstract interpretation framework within different IDEs takes advantage of our efficient and incremental fixpoint to achieve effective verification on-the-fly, as the program is developed. We also demonstrate a number of embeddings of this framework within the browser, and show as an example an application for building interactive tutorials, which we have used for teaching verification and abstract interpretation.

Program & Schedule

Times in the schedule are WEST (Western European Summer Time), i.e., local to Cascais.

Monday, October 23
11:00 - 11:10 OPENING



SESSION I. Chairs : Robert Glück and Santiago Escobar

  • Invited Talk PPDP+LOPSTR Unification Modulo Equational Theories in Languages with Binding Operators.
    Maribel Fernandez
  • Towards a Certified Proof Checker for Deep Neural Network Verification.
    Remi Desmartin, Omri Isac, Grant Passmore, Kathrin Stark, Guy Katz and Ekaterina Komendantskaya
12:30 - 14:00 Lunch Break




SESSION II. Chair: Michael Hanus

  • A Reusable Machine-Calculus for Automated Resource Analyses.
    Hector Suzanne and Emmmanuel Chailloux
  • A Logical Interpretation of Asynchronous Multiparty Compatibility.
    Marco Carbone, Sonia Marin and Carsten Schuermann
  • Relational Solver for Java Generics Type System.
    Peter Lozov, Dmitry Kosarev, Dmitry Ivanov and Dmitry Boulytchev
15:30 - 16:00 Coffee Break




SESSION III. Chairs : Chantal Keller

  • A Rule-Based Approach for Designing and Composing Abstract Domains.
    Daniel Jurjo, Jose F. Morales, Pedro Lopez-Garcia and Manuel V. Hermenegildo
  • Design Datalog Templates for Synthesizing Bidirectional Programs from Tabular Examples.
    Bach Nguyentrong, Kanae Tsushima and Zhenjiang Hu
  • Best Paper Awards.

Tuesday, October 24



SESSION IV. Chair: John Gallagher

  • Invited Talk On-The-Fly Verification via Incremental, Interactive Abstract Interpretation with CiaoPP and VeriFly.
    Manuel V. Hermenegildo
  • A Term Matching Algorithm and Substitution Generality.
    Marija Kulas
10:30 - 11:00 Coffee Break




SESSION V. Chairs : Maurizio Proietti

  • Predicate Anti-unification in (Constraint) Logic Programming.
    Gonzague Yernaux and Wim Vanhoof
  • A Novel EGs-Based Framework for Systematic Propositional-Formula Simplification.
    Jordina Francès de Mas and Juliana Bowles
  • From Static to Dynamic Access Control Policies via Attribute-Based Category Mining.
    Anna Bamberger and Maribel Fernandez
12:30 - 14:00 Lunch Break




SESSION VI. Chairs : Juliana Bowles

  • Constrained Horn Clauses Satisfiability via Catamorphic Abstractions.
    Emanuele De Angelis, Fabio Fioravanti, Alberto Pettorossi and Maurizio Proietti
  • Transforming Big-Step to Small-Step Semantics Using Interpreter Specialisation.
    John P. Gallagher, Manuel V. Hermenegildo, Jose F. Morales and Pedro Lopez-Garcia
  • Closing and Adjourn.


The aim of the LOPSTR series is to stimulate and promote international research and collaboration on logic-based program development. LOPSTR is open to contributions in logic-based program development in any language paradigm. LOPSTR has a reputation for being a lively, friendly forum for presenting and discussing work in progress.

LOPSTR 2023 will be held in-person at Hotel Cascais Miragem in Cascais, Lisbon, Portugal and will be co-located with PPDP 2023 as part of SPLASH 2023. At least one of the authors of the accepted paper is expected to attend the conference and present the paper. Information about venue and travel is available on the SPLASH 2023 website.

Topics of interest cover all aspects of logic-based program development, all stages of the software life cycle, and issues of both programming-in-the-small and programming-in-the-large, including, but not limited to:

  • synthesis
  • transformation
  • specialization
  • inversion
  • composition
  • optimisation
  • specification
  • analysis and verification
  • testing and certification
  • program and model manipulation
  • AI-methods for program development
  • verification and testing of AI-based systems
  • transformational techniques in software engineering
  • logic-based methods for security, cyber-physical and distributed system
  • applications, tools and industrial practice

Survey papers that present some aspects of the above topics from a new perspective and papers that describe experience with industrial applications and case studies are also welcome.


Submissions can be made in two categories:

  • Regular Papers (15 pages max.)
  • Short Papers (8 pages max.)
References do NOT count towards the page limit. Additional pages may be used for appendices not intended for publication. Reviewers are not required to read the appendices, and thus papers should be intelligible without them. All submissions must be written in English. Submissions must not substantially overlap with papers/tools that have been published or that are simultaneously submitted to a journal, conference, or workshop with refereed proceedings.

Submissions of Regular Papers must describe the original work. Work that already appeared in unpublished or informally published workshop proceedings may be submitted (please contact the PC chair in case of questions).

Submissions of Short Papers may include presentations of exciting if not fully polished research and tool demonstrations that are of academic and industrial interest. Tool demonstrations should describe the relevant system, usability, and implementation aspects of a tool.

All accepted papers will be included in the conference proceedings and published by Springer as a Lecture Notes in Computer Science (LNCS) volume.

After the symposium, a selection of a few best papers will be invited for submission to rapid publication in the Journal of Theory and Practice of Logic Programming (TPLP). Authors of selected papers will be invited to revise and/or extend their submissions to be considered for publication. The papers submitted to TPLP will be subject to the standard reviewing process of the journal.

Submission Guidelines

Authors should submit an electronic copy of the paper (written in English) in PDF, formatted in the Lecture Notes in Computer Science style. Each submission must include on its first page the paper title; authors and their affiliations; contact author's email; abstract; and three to four keywords which will be used to assist the PC in selecting appropriate reviewers for the paper. Authors should consult Springer's authors' instructions at the author's page, and use their proceedings templates, either for LaTeX (available also in overleaf) or for Word, for the preparation of their papers. Springer encourages authors to include their ORCIDs in their papers. In addition, upon acceptance, the corresponding author of each paper, acting on behalf of all of the authors of that paper, must complete and sign a Consent-to-Publish form. The corresponding author signing the copyright form should match the corresponding author marked on the paper. Once the files have been sent to Springer, changes relating to the authorship of the papers cannot be made.

Page numbers (and, if possible, line numbers) should appear on the manuscript to help the reviewers in writing their report. So, for LaTeX, we recommend that authors use:


Papers should be submitted via EasyChair: https://easychair.org/conferences/?conf=lopstr2023

Best Paper Award

Thanks to Springer's sponsorship, two best paper awards (one for each submission category) will be given at LOPSTR 2023. The program committee will select the winning papers based on relevance, originality and technical quality but may also take authorship into account (e.g. a student paper).


Program Chairs
Robert Glück University of Copenhagen, Denmark
Bishoksan Kafle IMDEA Software Institute, Spain
Publicity Chair
Daniel Jurjo IMDEA Software Institute, Spain
Program Committee Members
Slim Abdennadher German International University, Egypt
José Júlio Alferes Universidade Nova de Lisboa, Portugal
Roberto Amadini University of Bologna, Italy
William Byrd University of Alabama at Birmingham, USA
Michael Codish Ben-Gurion University of the Negev, Israel
Gregory Duck National University of Singapore, Singapore
Isabel Garcia University of Waterloo, Canada
Ashutosh Gupta IIT Bombay, India
Gopal Gupta The University of Texas at Dallas, USA
Michael Hanus University of Kiel, Germany
Temesghen Kahsai Amazon, USA
Maja Hanne Kirkeby Roskilde University, Denmark
Michael Leuschel Heinrich Heine University Düsseldorf, Germany
Nai-Wei Lin National Chung Cheng University, Taiwan
Fred Mesnard University of Reunion, France
José F. Morales IMDEA Software Institute, Spain
Carlos Olarte Université Sorbonne Paris Nord, France
Alberto Pettorossi Università di Roma Tor Vergata, Italy
Christoph Reichenbach Lund University, Sweden
Peter Schachte The University of Melbourne, Australia
Helge Spieker Simula Research Laboratory, Norway
Theresa Swift Universidade Nova de Lisboa, Portugal
Laura Titolo National Institute of Aerospace, USA
Kazunori Ueda Waseda University, Japan
Germán Vidal Universitat Politècnica de València, Spain
Nisansala Yatapanage Australian National University, Australia
Florian Zuleger Vienna University of Technology, Austria

Call for papers

The final call for papers can be found here.


LOPSTR is a renowned symposium that has been held for more than 30 years. The first meeting was held in Manchester, UK in 1991. Information about previous symposia can be found here.

You might have a look at the contents of past LOPSTR symposia at DBLP and past LNCS proceedings at Springer repository.

Contact Us

PC Chairs and
Local Organization
Robert Glück
University of Copenhagen
Bishoksan Kafle
IMDEA Software Institute, Spain
Vasco Thudichum Vasconcelos
General Chair, SPLASH
Andreia Mordido
Local Organizer Chair, SPLASH

In Cooperation with