derivative function of p_dT
function p_dT_der extends Modelica.Icons.Function; input SI.Density d "density"; input SI.Temperature T "temperature"; input ThermalSeparation.Media.WaterBasedLiquid.BaseClasses.Common.IF97BaseTwoPhase aux "auxiliary record"; input Real d_der "derivative of density"; input Real T_der "derivative of temperature"; output Real p_der "derivative of pressure"; end p_dT_der;