function der_density_pTxi extends TILMedia.BaseClasses.PartialVLEFluidObjectFunction; input SI.AbsolutePressure p "Pressure"; input SI.Temperature T "Temperature"; input SI.MassFraction[:] xi "Mass fractions of the first nc-1 components"; input TILMedia.Internals.TILMediaExternalObject vleFluidPointer; input Real der_p "Derivative of Pressure"; input Real der_T "Derivative of Temperature"; input Real[:] der_xi "Derivative of Mass fractions of the first nc-1 components"; output Real der_d "Derivative of Density"; end der_density_pTxi;