  We investigate models of the mitogenactivated protein kinases (MAPK) network,
with the aim of determining where in parameter space there exist multiple
positive steady states. We build on recent progress which combines various
symbolic computation methods for mixed systems of equalities and inequalities.
We demonstrate that those techniques benefit tremendously from a newly
implemented graph theoretical symbolic preprocessing method. We compare
computation times and quality of results of numerical continuation methods with
our symbolic approach before and after the application of our preprocessing.
