Call for Papers
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Constraints Journal
Special Issue on Abstraction and Automation in Constraint Modelling

Guest Editors

+ Alan M Frisch, University of York, UK.
+ Ian Miguel, University of St Andrews, UK.

Introduction

Constraint Programming (CP) is a powerful technology that has been
successfully used for tackling a wide range of real-life, complex
applications. To solve a problem with CP it first needs to be modelled
by a set of constraints that must be satisfied by any solution.
Because formulating such a model, and especially formulating one that
is solvable in practice, is often difficult, CP technology is
currently accessible to only a small number of experts. For CP to be
more widely used by non-experts, more research effort is needed in
order to ease the use of CP technology.

One way of improving usability is by extending CP technology to enable
models to be formulated at a higher level of abstraction. For
instance, support for set variables (variables whose domain values are
sets) in many constraint languages and solvers has abstracted away
from the low-level details of how the set variable is represented; the
user no longer needs to know these details. However, variables that
take certain other types of values, such as functions and relations,
are not yet supported directly by constraint solvers. In this case,
the abstract variable can be refined into a representation that
comprises a set of more primitive variables and a collection of
constraints among them. In order to avoid forcing the user to perform
this step manually, automated refinement is a key goal.

Automation can also aid the modelling process by transforming a
constraint model into one that can be solved more effectively.  Such
transformations include adding implied constraints, adding
symmetry-breaking constraints, adding constraints to exploit
dominances in optimisation problems, removing propagation-redundant
constraints and creating relaxed versions of the initial problem.

This special issue is devoted to the development and use of
abstraction and automation facilities in constraint modelling.
We invite submissions from interested authors in this
challenging and important area.

Topics of Interest include, but are not limited to:

+ The use of abstraction facilities in formulating models.
+ Abstraction in constraint languages.
+ Abstract variable domains.
+ Abstraction in search control.
+ Automated refinement.
+ Automated generation of implied constraints.
+ Automated generation of symmetry-breaking constraints.
+ Automated generation of constraints to exploit dominances.
+ Automated generation of relaxations.

Paper Submission

Researchers are invited to submit original papers that make a
significant contribution to the field to ianm@cs.st-and.ac.uk. (Note
that the usual on-line submission procedure for the Constraints
journal will not be followed initially for the Special Issue). All
submissions should be in .pdf format and follow Constraints Journal
guidelines. Papers of at most 30 journal pages are preferred.

When submitting, please use the subject "Constraints Special Issue
Paper Submission" and clearly specify the e-mail address and phone
number of the corresponding author. Receipt of papers will be
acknowledged. Submissions will be reviewed by at least two
reviewers. All accepted papers will meet the usual high-quality
standards of the Constraints Journal.

Authors intending to submit should send an expression of interest
(including a provisional title, list of authors and a few sentences
outlining the topic of the paper) to ianm@cs.st-and.ac.uk by May 1st,
2007.

Important Dates

Expression of interest: May 1st, 2007
Submission of papers: July 1st, 2007
Notification of acceptance: October 1st, 2007
Final versions of accepted papers: Dec 1st, 2007.
Expected publication of the special Issue: 2nd issue of 2008 (Apr 1st).

Important Links

*  Special issue home page: http://www.cs.st-andrews.ac.uk/~ianm/ModellingSpecialIssue.html
*  Constraints journal home page:
http://ai.uwaterloo.ca/~vanbeek/Constraints/constraints.html
*  Guidelines for authors:
http://ai.uwaterloo.ca/~vanbeek/Constraints/Instructions_for_Authors.html