The Indigo Algorithm
Authors: Alan Borning, Richard Anderson, and Bjorn Freeman-Benson
Published as UW Tech Report 96-05-01.
Inequality constraints are useful for specifying various aspects of user
interfaces, such as constraints that one window is to the left of another,
or that an object is contained within a rectangle. However, current local
propagation constraint solvers can't handle inequality constraints. We
present Indigo, an efficient local propagation algorithm for satisfying
acyclic constraint hierarchies, including inequality constraints.
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