Alexander Brodsky Catherine Lassez Jean-Louis Lassez Michael J. Maher Separability of Polyhedra for Optimal Filtering of Spatial and Constraint Data. 83-104 1999 23 J. Autom. Reasoning 1 db/journals/jar/jar23.html#BrodskyLLM99 http://dx.doi.org/10.1023/A:1006171919920