Helmholtz function for region 3: f(d,T)
function f3 extends Modelica.Icons.Function; input Units.SI.Density d "density"; input Units.SI.Temperature T "temperature (K)"; output ThermoSysPro.Properties.WaterSteam.Common.HelmholtzDerivs f "dimensionless Helmholtz function and dervatives wrt delta and tau"; end f3;