.TILMedia.BaseClasses.PartialGasObjectFunctions.der_isothermalCompressibility_phxi .TILMedia.BaseClasses.PartialGasObjectFunctions.der_isothermalCompressibility_phxipartial function der_isothermalCompressibility_phxi = TILMedia.BaseClasses.PartialGasObjectFunctionPrototypes.der_isothermalCompressibility_phxi;