  Two microscopic models, UrQMD and QGSM, are used to extract the effective
equation of state (EOS) of locally equilibrated nuclear matter produced in
heavy-ion collisions at energies from 11.6 AGeV to 160 AGeV. Analysis is
performed for the fixed central cubic cell of volume V = 125 fm**3 and for the
expanding cell that followed the growth of the central area with uniformly
distributed energy. For all reactions the state of local equilibrium is nearly
approached in both models after a certain relaxation period. The EOS has a
simple linear dependence P/e = c_s**2 with 0.12 < c_s**2 < 0.145. Heavy
resonances are shown to be responsible for deviations of the c_s**2(T) and
c_s**2(mu_B) from linear behavior. In the T-mu_B and T-mu_S planes the EOS has
also almost linear dependence and demonstrates kinks related not to the
deconfinement phase transition but to inelastic freeze-out in the system.
