PTHG-18: The Second Workshop on Progress Towards the Holy Grail

August 27, 2018, at CP 2018, Lille, France


Some twenty years ago the paper “In Pursuit of the Holy Grail” proposed that Constraint Programming was well-positioned to pursue the Holy Grail of computer science: the user simply states the problem and the computer solves it. This workshop will look at progress towards that goal, in particular regarding work on automating:

  • Problem Acquisition: learning, debugging, maintaining, etc.
  • Model Reformulation: transformation for efficient solution, redundant models, etc.
  • Solver Construction: adaptive parameter tuning, automated selection from portfolios, etc.
  • User Explanation: reasons for failure, implications for choices, etc.

Of special interest is the intersection of the Holy Grail goal with the increasing attention being paid to Human-Aware AI, machine learning, and intelligent software assistants.


8h30-9h00: Registration


  • Keynote: Cognitive Optimization: Jean-François Puget, IBM
  • Invited Talk: Learning Constraints from Examples: Luc De Raedt, KU Leuven

10h30-11h00: Coffee break


12h30-14h00: Lunch Break


Panel: Progress Towards the Holy Grail

  • Acquisition: Barry O’Sullivan, University College Cork, Ireland
  • Modelling: Ian Miguel, University of St Andrews, Scotland
  • Solving: Holger Hoos, Leiden University, The Netherlands
  • Explanation: Narendra Jussien, École des Mines d’Albi-Carmaux, France

15h30-16h00: Coffee break


Discussion: Roadmap for Further Progress

  • Scientific: Goals, Milestones, etc.
  • Support: Collaborations, Resources, etc.

Organizing Committee:

Chair: Eugene Freuder, University College Cork, Ireland:

Christian Bessière, CNRS – Université Montpellier, France

Lars Kotthoff, University of Wyoming, USA

Ian Miguel, University of St Andrews, Scotland

Barry O’Sullivan, University College Cork, Ireland