+// overloading at work: we cannot use the macros here
+/** Harmonic polylogarithm with only positive parameters. */
+class H2_SERIAL { public: static unsigned serial; };
+template<typename T1, typename T2>
+inline function H(const T1& p1, const T2& p2) {
+ return function(H2_SERIAL::serial, ex(p1), ex(p2));
+}
+/** Harmonic polylogarithm with signed parameters. */
+class H3_SERIAL { public: static unsigned serial; };
+template<typename T1, typename T2, typename T3>
+inline function H(const T1& p1, const T2& p2, const T3& p3) {
+ return function(H3_SERIAL::serial, ex(p1), ex(p2), ex(p3));
+}
+class H_SERIAL;
+template<> inline bool is_the_function<class H_SERIAL>(const ex& x)
+{
+ return is_the_function<H2_SERIAL>(x) || is_the_function<H3_SERIAL>(x);
+}