function rhovl_p_der extends Modelica.Icons.Function; input SI.Pressure p "saturation pressure"; input ThermalSeparation.Media.WaterBasedLiquid.BaseClasses.Common.IF97PhaseBoundaryProperties bpro "property record"; input Real p_der "derivative of pressure"; output Real d_der "time derivative of density along the phase boundary"; end rhovl_p_der;