@TechReport{	  it:2004-022,
  author	= {Pascal Van Hentenryck and Pierre Flener and Justin Pearson
		  and Magnus {\AA}gren},
  title		= {Compositional Derivation of Symmetries for Constraint
		  Satisfaction},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Computing Science Division},
  year		= {2004},
  number	= {2004-022},
  month		= may,
  abstract	= {This paper reconsiders the problems of discovering
		  symmetries in constraint satisfaction problems (CSPs). It
		  proposes a compositional approach which derives symmetries
		  of the applications from primitive constraints. Its key
		  insight is the recognition of the special role of global
		  constraints in symmetry detection. Once the symmetries of
		  global constraints are available, it often becomes much
		  easier to derive symmetries compositionally and
		  efficiently. The paper demonstrates the potential of this
		  approach by studying several classes of value and variable
		  symmetries and applying the resulting techniques to two
		  non-trivial applications. The paper also discusses the
		  potential of reformulations and high-level modelling
		  abstractions to strengthen symmetry discovery.}
}