Un sous-système d'un système plat de dimension différentielle 2 est plat. A subsystem of a flat system of differential dimension 2 is flat
arXiv:1702.00264
Abstract
Un sous-système de dimension différentielle au plus 2 d'une extension plate est plate. Si un tel système plat est stationnaire, il admet des sorties plates indépendantes du temps. A subsystem of a flat system of differential dimension at most 2 is flat. Furthermore, if such a flat system is stationary, we show that there exist flat utputs not depending on the time.
12 pages, in French. With an extended English abstract. A second version where the proof of the main theorem has been corrected using an extended new version of Rouchon's lemma