inverse iteration in region 3: (d) = f(p,T)
function dofpt3 import ThermoSysPro; extends Modelica.Icons.Function; input Units.SI.Pressure p "pressure"; input Units.SI.Temperature T "temperature (K)"; input Units.SI.Pressure delp "iteration converged if (p-pre(p) < delp)"; output Units.SI.Density d "density"; output Integer error = 0 "error flag: iteration failed if different from 0"; end dofpt3;