function setState_psX_der
input AbsolutePressure p "Pressure";
input SpecificEntropy s "Specific entropy";
input MassFraction X[:] = reference_X "Mass fractions";
input FixedPhase phase = 0 "2 for two-phase, 1 for one-phase, 0 if not known";
input Real der_p "Time derivative of pressure";
input Real der_s "Time derivative of specific entropy";
input Real der_X[:] "Time derivative of mass fractions";
output ThermodynamicState der_state "Time derivative of thermodynamic state";
end setState_psX_der;