function density_derp_h_pTX input Modelica.SIunits.Pressure p "Pressure"; input Modelica.SIunits.Temperature T "Temperature"; input Modelica.SIunits.MassFraction X[nC] = reference_X "Mass fraction"; input Properties state; input MultiPhaseMixture.Templates.ExternalObjects.ExternalMediaObject eo "External object"; output Real ddph "Density derivative wrt p at constant enthalpy"; end density_derp_h_pTX;