Yohan Boichut Roméo Courbis Pierre-Cyrille Héam Olga Kouchnarenko Finer Is Better: Abstraction Refinement for Rewriting Approximations. 48-62 2008 RTA http://dx.doi.org/10.1007/978-3-540-70590-1_4 conf/rta/2008 db/conf/rta/rta2008.html#BoichutCHK08