Tairan, Yin/Inria, Univ Rennes, CNRS, IRISA, France; Ludovic Hoyet/Inria, Univ Rennes, CNRS, IRISA, France; Marc Christie/ Inria, Univ Rennes, CNRS, IRISA, France; Marie-Paule Cani/Ecole Polytechnique, CNRS (LIX), IP Paris, France; Julien Pettré/Inria, Univ Rennes, CNRS, IRISA, France