In order to investigate relativistic effects we compare the transverse flow
calculated by using the four versions of the QMD approaches with that of the
full covariant RQMD approach. From the comparison we conclude that the
simplified RQMD (RQMD/S), which uses the common time coordinate to all
particles, can be used instead of RQMD up to 6 GeV/u.Comment: 6pages, Latex is used, 1 Postscript figures are available by request
from [email protected]