@TechReport{	  it:2006-020,
  author	= {Nicolas Beldiceanu and Pierre Flener and Xavier Lorca},
  title		= {Combining Tree Partitioning, Precedence, Incomparability,
		  and Degree Constraints, with an Application to Phylogenetic
		  and Ordered-Path Problems},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Computing Science Division},
  year		= {2006},
  number	= {2006-020},
  month		= apr,
  abstract	= {The \emph{tree} and \emph{path} constraints, for digraph
		  partitioning by vertex disjoint trees and paths
		  respectively, are unified within a single global
		  constraint, including a uniform treatment of a variety of
		  useful side constraints, such as precedence,
		  incomparability, and degree constraints. The approach
		  provides a sharp improvement over an existing \emph{path}
		  constraint, but can also efficiently handle tree problems,
		  such as the phylogenetic supertree construction problem.
		  The key point of the filtering is to take partially into
		  account the strong interactions between the tree
		  partitioning problem and all the side constraints.}
}