Graph-Relational Data, Ontologies, and Rules

February 12, 2019 at 10:48 PM

Combinations of the Semantic Web, Graph Databases, and Logic Programming are explored. Data are complemented by Knowledge (Ontologies and Rules). Graphs and Relations are integrated. The ensuing synergies cross-fertilize tools and techniques and contribute to eXplainable Artificial Intelligence and IT at large. As an example, representations of Cypher's Labeled Property Graphs in RDF and PSOA RuleML are discussed.



RuleML+RR 2018 Report

January 24, 2019 at 3:06 PM
The 2nd International Joint Conference on Rules and Reasoning RuleML+RR 2018 was held on September 18-21, 2018, at campus Belval of the University of Luxembourg. The conference was organised as one of several collocated events of the Luxembourg Logic for AI Summit 2018, which was substantially supported by the Luxembourg National Research Fund (FNR, RESCOM/18/12426287).

The Luxembourg Logic for AI Summit 2018 (LuxLogAI 2018, September 17-26, 2018) summit had a special theme: tools and methods for responsible AI. The summit brought together a number of events, including (besides RuleML+RR 2018):

  • the 4th Global Conference on Artificial Intelligence (GCAI 2018), a young international conference series covering all topics in AI;
  • DecisionCAMP 2018, a renowned event series in the field of business rules and decision management technology;
  • the 14th Reasoning Web Summer School (RW 2018), a high-level educational initiative devoted to reasoning techniques related to the semantic web, linked data and knowledge graph application scenarios;
  • MIning and REasoning with legal texts (MIREL 2018), an international workshop in the field of legal reasoning;
  • Deduktionstreffen 2018, the annual meeting of the deduction systems chapter of the German Gesellschaft für Informatik;
  • AI: Truth or Dare, a public round table discussion on responsible AI and the European future with high profile panelists from politics, industry and academia;
  • AI and Art, a combination of art exhibitions,  cultural events and discussion sessions;
  • a workshop on self-organising systems and a tutorial on advanced belief change and default entailment.

LuxLogAI 2018 featured a stellar line-up of eleven internationally recognized invited speakers, complemented by regular presentations of research papers.

RuleML+ RR 2018 provided a rich programme, with five keynote talks, two tutorials, a regular program together with several sub-events: an industry track, the 12th International Rule Challenge 2018 , a doctoral consortium and a poster session.

The five keynote presenters were:

  • Hannah Bast (University of Freiburg) presenting  "Efficient and Convenient Search on Very Large Knowledge Bases"
  • Georg Gottlob (University of Oxford) presenting "Vadalog: A Language and System for Knowledge Graphs"
  • Guido Governatori (Data61/CSIRO) presenting  "Modal Rules: Extending Defeasible Logic with Modal Operators"
  • Valeria de Paiva (Nuance Communications) presenting "Bridging Trouble”
  • Philipp Slusallek (Saarland University/DFKI) presenting "Understanding the World with AI: Training and Validating Autonomous Systems Using Synthetic Data"

Gottlob, de Paiva and Slusallek were each a joint GCAI keynote.

The two tutorials were:

  • LegalRuleML, by Guido Governatori (Data61/CSIRO) and Monica Palmirani (Bologna University)
  • Logic and Smart Contracts, by Bob Kowalski (Imperial College London), Miguel Calejo ( and Fariba Sadri (Imperial College London)

The regular program included ten full research papers and twelve technical communication papers selected from thirty-three submissions. The presentations were grouped in seven sessions: description logic; KR systems and applications;  ontological reasoning; benchmarking; reasoning with modalities; complex event processing; rule system and applications. Presentation abstracts and a selection of slides are available on-line:

Information on the various LuxLogAI conference proceedings, including the Springer LNCS proceedings of RuleML+RR 2018, are available at:

The Doctoral Consortium (DC) consisted of four papers, one of which, the winner of the DC best paper award, was presented as a full research paper and is contained in the RuleML+RR 2018 proceedings. The six presentations and demos of the Rule Challenge addressed diverse areas, like air traffic control regulations, the British Succession to the Crown Act 2013', rule mining and ontologies.  The industry track consisted of four invited presentations on the topic of rule languages and AI in industry. It was followed by the highly successful public round table discussion event  AI: Truth or Dare at KPMG Luxembourg devoted to Responsible Artificial Intelligence and the European future. This public round table was perhaps one of the main highlights of the LuxLogAI conference. The panel consisted of nine experts in AI from politics, industry and academia, like for instance Viviane Reding, former vice president of the European Union. The event had repercussion in the media, see The poster session of RuleML+RR was combined with that of the Deduktionstreffen, and consisted of seven poster presentations.

The LuxLogAI conference dinner took place on a boat on the Moselle river during a cruise in the evening. Artist Egberdien van der Torre gave an art performance, and Yolanda Spinola-Elias (University of Seville) held a dinner speech entitled “An AI+A serendipity?”. She explained that Artificial Intelligence and Art confluences and conjunctions may not rely only on a serendipity process, but on a deeply intentional Art, Science, Technology and Society creative research system. Meta, multi and/or interdisciplinary creative processes were some of the issues that “AI and Art” covered during LuxLogAI 2018 in order to provide a wide perspective of AI impact in Art and vice versa.

LuxLogAI attracted a total of 224 registered participants. Of these 224 participants, approx. 100 attended RuleML+RR and GCAI.

The conference produced several award winners:

  • The LuxLogAI/GCAI best student paper award was given to Ruin Silva, Francisco S. Melo and Manuela Veloso, for their paper “What if the world were different? Gradient-based exploration for new optimal policies”.
  • The winners of the RuleML+RR best paper award were Stathis Delivorias, Michel Leclere, Marie-Laure Mugnier and Federico Ulliana, for their paper entitled “On the k-Boundedness for Existential Rules".
  • The winners of the RuleML+RR Best rule challenge demo were Theodoros Mitsikas, Sofia Almpani, Petros Stefaneas, Panayiotis Frangos and Iakovos Ouranos  for their presentation entitled “Formalizing Air Traffic Control Regulations in PSOA RuleML”.
  • The winner of the RuleML+RR best poster award was Lukas Grätz, for his contribution entitled “Concepts as Modalities in Description Logics”.

A selection of the papers with the highest reviewing scores were invited to submit an extended version of their papers to the Special issue on “Logic Rules and Reasoning” of the Journal of Theory and Practice of Logic Programming (TPLP).

A special thanks goes to all sponsors of RuleML+RR 2018 and LuxLogAI 2018: Binarypark; the Computer Science and Communications (CSC) Research Unit at the University of Luxembourg; the Department of Mathematics and Computer Science at the University of Calabria; the Interdisciplinary Centre for Security, Reliability and Trust (SnT) and the Interdisciplinary Lab for Intelligent and Adaptive Systems (ILIAS) at the University of Luxembourg; LogicalContracts; the Luxembourg National Research Fund (FNR); oXygen; and Springer. A special thanks also goes to the publisher, Springer, for their cooperation in editing and publishing the conference proceedings, and to the CEUR voluntary organisation and EasyChair Publications for providing the facility to publish the proceedings of the conference sub-events.

The 3nd Int'l Joint Conference on Rules and Reasoning is planned as part of the second edition of the Logic for AI Summit. It will take place in Bolzano in Italy in September 2019.

PSOA RuleML Explained with Blockchain Examples

December 6, 2018 at 2:55 PM
Grailog Visualizations, Herbrand Models, and PSOATransRun Queries

The PSOA RuleML language and its PSOATransRun engine provide cross-paradigm deductive querying. Knowledge representation in PSOA RuleML is explored with a progression of data and rules built from relations (tables), objects (graphs), as well as their systematic integration and extension. All kinds of data from this PSOA systematics are visualized by generalized (hyper)graphs in an extended Grailog. Building on relational Herbrand models, object-centered and object-relational Herbrand models are presented as a novel model-theoretic semantics for such data and rules. Comprehensive PSOATransRun query & answer pairs for the same PSOA knowledge bases exemplify the proof-theoretic semantics. General notions are illustrated by varieties of transitive closure as high-level knowledge about blockchains like Gridcoin and Chia Network.


Knowledge Authoring for Rule-based Reasoning,

October 29, 2018 at 9:40 AM
Modern knowledge bases have matured to the extent of being capable of complex reasoning at scale. Unfortunately, wide deployment of this technology is still hindered by the fact that specifying the requisite knowledge requires skills that most domain experts do not have, and skilled knowledge engineers are in short supply. A way around this problem could be to acquire knowledge from text.

The current knowledge acquisition technologies for information extraction are not up to the task because logic reasoning systems are extremely sensitive to errors in the acquired knowledge, and existing techniques lack the required accuracy by too large of a margin. Because of the enormous complexity of the problem, controlled natural languages (CNLs) were proposed in the past, but even they lack high enough accuracy. Instead of tackling the general problem of text understanding, our interest is in a related, but different, area of knowledge authoring—a technology designed to enable domain experts to manually create formalized knowledge using CNL. Our KALM system approach adopts and formalizes the FrameNet methodology for representing the meaning, enables incrementally-learnable and explainable semantic parsing, and harnesses rich knowledge graphs like BabelNet in the quest to obtain unique, disambiguated meaning of CNL sentences. Our experiments show that this approach is 95.6% accurate in standardizing the semantic relations extracted from CNL sentences—far superior to alternative systems.

For more information, see KALM Code and KALM short presentation.

Luxembourg Logic for AI Summit: Second Call For Participation

August 6, 2018 at 11:24 AM
Second Call For Participation Luxembourg Logic for AI Summit (LuxLogAI 2018) *** The early registration deadline is on 09-August-2018 *** 17-26 Sep 2018, Luxembourg
Second Call For Participation (early registration deadline approaching)
Luxembourg Logic for AI Summit (LuxLogAI 2018)

17-26 Sep 2018, Luxembourg

***   The early registration deadline is on 09—August-2018   ***
  Both student and regular early registrants receive €100 off.

***   The normal registration deadline is on 01—Septemeber-2018   ***
  Registrations after the deadline are considered as late registrations.
     For regular registrants (non-students), a late fee applies.


The Luxembourg Logic for AI Summit (LuxLogAI 2018) brings together the 2nd International Joint Conference on Rules and Reasoning (RuleML+RR 2018), the Reasoning Web Summer School (RW 2018), the Global Conference on Artificial Intelligence (GCAI 2018), DecisionCAMP 2018, the MIREL workshop and the annual meeting of the Deduction Systems group (Deduktionstreffen 2018).

With its special focus theme on “methods and tools for responsible AI”, a core objective of LuxLogAI is to present the latest developments and progress made on the crucial question of how to make AI more transparent, responsible and accountable.

The summit will provide a forum for stimulating cooperation and cross-fertilization between the many different communities focused on the research, development and applications of Artificial Intelligence and Rule-based Systems. We invite you to join rigorous researchers and inventive practitioners in Luxembourg, a world-class location for research, development and innovation at the heart of Europe.

- Luxembourg National Research Fund (FNR)
- The University of Luxembourg
- Interdisciplinary Centre for Security, Reliability and Trust (SnT)
- Interdisciplinary Lab for Intelligent and Adaptive Systems (ILIAS)
- Digital Luxembourg (sponsor for Diversity@LuxLogAI)

==Keynotes & Speakers==
- Hannah Bast (Uni Freiburg)
- Pascal Fontaine (Uni Lorraine)
- Georg Gottlob (Uni Oxford)
- Guido Governatori (CSIRO, Data61)
- Cynthia Kop (Radboud Uni Nijmegen)
- Valeria de Paiva (Nuance Communications)
- Philipp Slusallek (Saarland Uni)
- Daniele Nardi (Uni Roma)
Daphna Weinshall (Hebrew Uni Jerusalem)
- Bob Kowalski (Imperial College) and Miguel Calejo (
- Fariba Sadri (Imperial College London)
Monica Palmirani (Uni Bologna)
Yolanda Spinola-Elias (Uni Seville)

==Multiple Events Summit==
- MIREL (MIning and REasoning with Legal texts) Workshop: 17 September 2018.
- 4th Global Conference on Artificial Intelligence (GCAI 2018): 17-19 September 2018.
- DecisionCAMP (Business Rules and Decision Management Technology): 17-19 September 2018.
- AI and ART: 17-19 September 2018.
- 2nd International Joint Conference on Rules and Reasoning (RuleML+RR 2018): 18-21 September 2018.
- AI Public Event: 19 September with Viviane Reding [(European Parliament), Toby Walsh (UNSW Sydney), Claude Adam (University of Luxembourg), Philipp Slusallek (DFKI, Saarland University)]
- Self Organizing Systems (SOS): 19 September 2018. 
- Diversity@LuxLogAI: 20 September 2018.
- Annual meeting of the Deduction Systems group of GI e.V. (Deduktionstreffen 2018): 21 September 2018.
- Reasoning Web Summer School (RW 2018): 22-26 September 2018.

==Open Calls==
- RuleML+RR Posters, see Call for Posters, Extended deadline: 8 August 2018
- Deduktionstreffen 2018, see Call for Abstracts, Deadline: 5 August 2018

Registration is open via EasyChair (
- Early registration deadline: 9 August, 2018
- Normal registration deadline: 1 September, 2018
- After normal registration deadline, a late registration fee applies (for non-students)

- Summit Chair (LuxLogAI):
  Leon van der Torre (U Luxembourg)
- General Chair (RuleML+RR):
  Xavier Parent (U Luxembourg)
- Program Chairs:
  Christoph  Benzmüller  (U  Luxembourg  &  FU Berlin)
  Francesco Ricca (U Calabria)
- Proceedings Chair:
  Dumitru Roman (SINTEF/U Oslo)
- Industry Track Chair:
  Silvie Spreeuwenberg (LibRT Amsterdam)
- Doctoral Consortium Chair
  Kia Teymouria (Boston University, Metropolitan College)
  Paul Fodor (Stony Brook University)
- Int’l Rule Challenge Chairs:
  Giovanni De Gasperis (U L’Aquila)
  Wolfgang Faber (Alpen-Adria-U Klagenfurt)
  Adrian Giurca (BTU Cottbus- Senftenberg)
- Reasoning Web (RW) Summer School
  Claudia d’Amato (U Bari)
  Martin Theobald (U Luxembourg)
- Publicity Chair:
  Amal Tawakuli (U Luxembourg)
- Financial Chair
  Martin Theobald (U Luxembourg)
- Poster Chair
  Alex Steen (U Luxembourg)

- Web:
- Twitter:
- Instagram:
- RuleML Blog:

Schéi Gréiss | Mit Freundlichen Grüßen | Meilleures Salutations | With Kind Regards

Amal Tawakuli (
CSC Research Unit

LuxLogAI 2018 Important Calls (Posters, Abstracts and Grants)

May 25, 2018 at 4:55 PM
Important Calls (Posters, Abstracts and Grants)
Luxembourg Logic for AI Summit (LuxLogAI 2018)
17-26 Sep 2018, Luxembourg

The Luxembourg Logic for AI Summit (LuxLogAI 2018) brings together the 2nd International Joint Conference on Rule and Reasoning (RuleML+RR 2018), the Reasoning Web Summer School (RW 2018), the Global Conference on Artificial Intelligence (GCAI 2018), DecisionCAMP 2018 and the annual meeting of the Deduction Systems group (Deduktionstreffen 2018) of the German Gesellschaft für Informatik (GI).

With its special focus theme on “methods and tools for responsible AI”, a core objective of LuxLogAI is to present the latest developments and progress made on the crucial question of how to make AI more transparent, responsible and accountable.

==First Call For Posters==
RuleML+RR 2018 calls for additional short poster papers related to theoretical advances, novel technologies, and innovative applications concerning knowledge representation and reasoning with rules. A Best Poster Award will be given to the best poster presentation.

The full Call for Posters, including submission details, is available at

Important dates:
-Poster paper submission: 1 August 2018
-Author notification: 15 August 2018
-Camera-ready submission: 31 August 2018

==First Call For Abstracts==
The annual meeting Deduktionstreffen (Deduktionstreffen 2018) is the prime activity of the Interest Group for Deduction Systems (FGDedSys) of the German Informatics Society (Gesellschaft für Informatik). It is a meeting with a familiar, friendly atmosphere, where everyone (not only the German community) interested in deduction can report on their work in an informal setting. The Deduktionstreffen will also host the annual general meeting of the members of FGDedSys. Contributions on all theoretical, experimental and application aspects of deduction are welcome.

Invited speakers:
Cynthia Kop (Radboud University Nijmegen)
Pascal Fontaine (Université de Lorraine, Nancy)

For further information about the Deduktionstreffen 2018, please visit

Important dates:
-Early bird submission: 5 July 2018 (Notification: 15 July 2018)
-Standard submission: 5 August 2018 (Notification: 15 August 2018)
-Deduktionstreffen: 21 September 2018

==First Call For Applications==
In order to give PhD students and Postdocs (with limited funding) the opportunity to attend LuxLogAI, the organizers are awarding a number of grants to motivated applicants. In return, successful applicants are asked to assist the local organization team during the conference.

For further details, including how to submit your application, visit

Important dates:
-Early bird application deadline: 30 June 2018
-Successful applicants will be notified before: 15 August 2018
-Second round application deadline: 20 August 2018
-Successful applicants will be notified on: 1 September 2018