@TechReport{	  it:2007-032,
  author	= {Pierre Flener and Justin Pearson and Meinolf Sellmann and
		  Van Hentenryck, Pascal and Magnus {\AA}gren},
  title		= {Structural Symmetry Breaking for Constraint Satisfaction
		  Problems},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Computing Science Division},
  year		= {2007},
  number	= {2007-032},
  month		= nov,
  abstract	= {In recent years, symmetry breaking for constraint
		  satisfaction problems (CSPs) has attracted considerable
		  attention. Various general schemes have been proposed to
		  eliminate symmetries. In general, these schemes may take
		  exponential space or time to eliminate all the symmetries.
		  We identify several classes of CSPs that encompass many
		  practical problems and for which symmetry breaking for
		  various forms of value or variable interchangeability is
		  tractable using dedicated search procedures. We also show
		  the limits of efficient symmetry breaking for such
		  dominance-detection schemes by proving intractability
		  results for some classes of CSPs. }
}