1. INRIA Saclay - hatIle-de- INRIA Saclay - hatIle-de- France and CMAP France and CMAP CMAP, École Polytechnique CMAP, École Polytechnique 91128 Palaiseau Cedex 91128 Palaiseau Cedex France France
2. INRIA Saclay - hatIle-de- France and CMAP CMAP, École Polytechnique 91128 Palaiseau Cedex France