derivative function of h_dT
function h_dT_der extends Modelica.Icons.Function; input Units.SI.Density d "density"; input Units.SI.Temperature T "temperature"; input ThermoSysPro.Properties.WaterSteam.Common.IF97BaseTwoPhase aux "auxiliary record"; input Real d_der "derivative of density"; input Real T_der "derivative of temperature"; output Real h_der "derivative of specific enthalpy"; end h_dT_der;