MathematicaStream & operator<<(MathematicaStream & ms, string const & s);
MathMLStream & operator<<(MathMLStream & ms, string const & s);
OctaveStream & operator<<(OctaveStream & os, string const & s);
MathematicaStream & operator<<(MathematicaStream & ms, string const & s);
MathMLStream & operator<<(MathMLStream & ms, string const & s);
OctaveStream & operator<<(OctaveStream & os, string const & s);