+bool constant::is_polynomial(const ex & var) const
+{
+ return true;
+}
+
+ex constant::conjugate() const
+{
+ if ( domain==domain::real || domain==domain::positive )
+ return *this;
+ return conjugate_function(*this).hold();
+}
+
+ex constant::real_part() const
+{
+ if ( domain==domain::real || domain==domain::positive )
+ return *this;
+ return real_part_function(*this).hold();
+}
+
+ex constant::imag_part() const
+{
+ if ( domain==domain::real || domain==domain::positive )
+ return 0;
+ return imag_part_function(*this).hold();
+}
+