TY - JOUR AU - Díaz Díaz, Jesús Ildefonso PY - 1991 SN - 0764-4442 UR - https://hdl.handle.net/20.500.14352/57511 T2 - Comptes Rendus de l'Académie des Sciences. Série I. Mathématique AB - We show how the approximate controllability of nonlinear parabolic problems may fail although it is a well-known property for linear equations. For the case of the obstacle problem the answer depends on the negativeness of the righ hand side term and... LA - fra M2 - 519 PB - Elsevier KW - approximate controllability KW - nonlinear parabolic problems KW - obstacle problem TI - On the approximate controllability of variational inequalities and others nonlinear parabolic problems TY - journal article VL - 312 ER -