-/** Return a reference to the pseries object embedded in an expression.
- * The result is undefined if the expression does not contain a pseries
- * object at its top level.
- *
- * @param e expression
- * @return reference to pseries object
- * @see is_ex_of_type */
-inline const pseries &ex_to_pseries(const ex &e)
+
+// utility functions
+
+/** Specialization of is_exactly_a<pseries>(obj) for pseries objects. */
+template<> inline bool is_exactly_a<pseries>(const basic & obj)