Hello All, 1) I find something like GINAC_DECLARE_REGISTERED_CLASS_INLINE to be very useful to define virtual member functions like archive, unarchive etc. inside the class definition. (This macro should not declare these functions, ofcourse) 2) Should numeric and ex have constructors that take std::complex<double> to initialize a complex number? This makes integration of GiNaC into other libraries simpler. cheers, Krishna.