+ bool info(unsigned inf) const override;
+ ex evalf() const override;
+ bool is_polynomial(const ex & var) const override;
+ ex conjugate() const override;
+ ex real_part() const override;
+ ex imag_part() const override;
+ void archive(archive_node& n) const override;
+ void read_archive(const archive_node& n, lst& syms) override;