  The mechanism of fusion hindrance, an effect preventing the synthesis of
superheavy elements in the reactions of cold and hot fusion, is investigated
using the Boltzmann-Uehling-Uhlenbeck equation, where Coulomb interaction is
introduced. A strong sensitivity is observed both to the modulus of
incompressibility of symmetric nuclear matter, controlling the competition of
surface tension and Coulomb repulsion, and to the stiffness of the
density-dependence of symmetry energy, influencing the formation of the neck
prior to scission. The experimental fusion probabilities were for the first
time used to derive constraints on the nuclear equation of state. A strict
constraint on the modulus of incompressibility of nuclear matter $K_0 = 240 -
260$ MeV is obtained while the stiff density-dependences of the symmetry energy
($\gamma>1.$) are rejected.
