  We show in detailed numerical solutions of the nonlinear Fokker-Planck
equation (FPE) which has been associated with nonextensive q-statistics that
the available data on rapidity distributions for stopping in relativistic
heavy-ion collisions cannot be reproduced with any permitted value of the
nonextensivity parameter (1 < q < 1.5). This casts doubt on the nonextensivity
concept that is widely used in relativistic heavy-ion physics.
