Derivative function of rho_pT
function rho_pT_der extends Modelica.Icons.Function; input SI.Pressure p "Pressure"; input SI.Temperature T "Temperature"; input Common.IF97BaseTwoPhase aux "Auxiliary record"; input Real p_der "Derivative of pressure"; input Real T_der "Derivative of temperature"; output Real rho_der "Derivative of density"; end rho_pT_der;