@property<EOL><INDENT>def SGl(self):<DEDENT>
rhol = self.rhol<EOL>if rhol is not None:<EOL><INDENT>return SG(rhol)<EOL><DEDENT>return None<EOL>
r'''Specific gravity of a hypothetical liquid phase of the mixture at  
        the specified temperature and pressure, [dimensionless].
        The reference condition is water at 4 °C and 1 atm 
        (rho=999.017 kg/m^3). For liquids, SG is defined that the reference
        chemical's T and P are fixed, but the chemical itself varies with
        the specified T and P.

        Examples
        --------
        >>> Mixture('water', ws=[1], T=365).SGl
        0.9650065522428539