@Article{ chagiapon, author = { Chambolle, Antonin and Giacomini, Alessandro and Ponsiglione, Marcello }, title = { Piecewise rigidity }, journal = { J. Funct. Anal. }, year = { 2007 }, volume = { 244 }, pages = { 134-153 }, URL = { http://cvgmt.sns.it/paper/752/ }, note = { cvgmt preprint} }