@TechReport{	  it:2007-009,
  author	= {Magnus {\AA}gren and Pierre Flener and Justin Pearson},
  title		= {On Constraint-Oriented Neighbours for Local Search},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Computing Science Division},
  year		= {2007},
  number	= {2007-009},
  month		= mar,
  abstract	= {In the context of local search, we investigate the
		  exploration of constraint-oriented neighbourhoods, where a
		  set of constraints is picked before considering the
		  neighbouring configurations where those constraints may
		  have a different penalty. Given the semantics of a
		  constraint, neighbourhoods consisting only of
		  configurations with decreased (or preserved, or increased)
		  penalty can be represented intensionally as a new attribute
		  for constraint objects. We present a framework for
		  combining neighbourhoods that allows different local search
		  heuristics to be expressed, including multi-phase
		  heuristics where an automatically identifiable suitable
		  subset of the constraints is satisfied upon a first phase
		  and then preserved in a second phase. This simplifies the
		  design of local search algorithms compared to using just a
		  variable-oriented neighbourhood, while not incurring any
		  runtime overhead.}
}