  Recent SPS data on the rapidity distribution of protons in p+S, p+Au and S+S
collisions at 200 AGeV and preliminary Pb+Pb collisions at 160 AGeV are
compared to HIJING and VENUS calculations as well as to predictions based on
the Multi-Chain Model (MCM). The preliminary Pb data suggest that a linear
dependence of the proton rapidity shift as a function of the nuclear thickness,
as first observed in p+A reactions, may apply up to Pb+Pb reactions. The
observed rapidity dependence of produced hyperons in both p+A and A+A reactions
however cannot be explained in terms of such models without introducing
additional non-linear effects.
