Alberto Pettorossi Maurizio Proietti Valerio Senni Proving Properties of Constraint Logic Programs by Eliminating Existential Variables. 179-195 2006 conf/iclp/2006 ICLP http://dx.doi.org/10.1007/11799573_15 db/conf/iclp/iclp2006.html#PettorossiPS06