Lagrangian method enhanced with edge swapping for the free fall and contact problem Étienne Bernard, Stéphane Del Pino, Erwan Deriaz, Bruno Després, Katerina Jurkova and Frédéric Lagoutière ESAIM: Proc., 24 (2008) 46-59 Published online: 10 October 2008 DOI: 10.1051/proc:2008029