.TILMedia.Internals.GasConfigurations.AnalyticDerivatives.GasObjectFunctions.density_pTxi .TILMedia.Internals.GasConfigurations.AnalyticDerivatives.GasObjectFunctions.density_pTxifunction density_pTxi = TILMedia.Internals.GasObjectFunctions.density_pTxi;