+// overloading at work: we cannot use the macros here
+/** Generalized multiple polylogarithm. */
+class G2_SERIAL { public: static unsigned serial; };
+template<typename T1, typename T2>
+inline function G(const T1& x, const T2& y) {
+ return function(G2_SERIAL::serial, ex(x), ex(y));
+}
+/** Generalized multiple polylogarithm with explicit imaginary parts. */
+class G3_SERIAL { public: static unsigned serial; };
+template<typename T1, typename T2, typename T3>
+inline function G(const T1& x, const T2& s, const T3& y) {
+ return function(G3_SERIAL::serial, ex(x), ex(s), ex(y));
+}
+class G_SERIAL;
+template<> inline bool is_the_function<G_SERIAL>(const ex& x)
+{
+ return is_the_function<G2_SERIAL>(x) || is_the_function<G3_SERIAL>(x);
+}
+
+/** Polylogarithm and multiple polylogarithm. */
+DECLARE_FUNCTION_2P(Li)
+
+/** Nielsen's generalized polylogarithm. */
+DECLARE_FUNCTION_3P(S)
+
+/** Harmonic polylogarithm. */
+DECLARE_FUNCTION_2P(H)
+
+/** Gamma-function. */
+DECLARE_FUNCTION_1P(lgamma)
+DECLARE_FUNCTION_1P(tgamma)
+
+/** Beta-function. */
+DECLARE_FUNCTION_2P(beta)
+
+// overloading at work: we cannot use the macros here
+/** Psi-function (aka digamma-function). */
+class psi1_SERIAL { public: static unsigned serial; };
+template<typename T1>
+inline function psi(const T1 & p1) {
+ return function(psi1_SERIAL::serial, ex(p1));
+}
+/** Derivatives of Psi-function (aka polygamma-functions). */
+class psi2_SERIAL { public: static unsigned serial; };
+template<typename T1, typename T2>
+inline function psi(const T1 & p1, const T2 & p2) {
+ return function(psi2_SERIAL::serial, ex(p1), ex(p2));
+}
+class psi_SERIAL;
+template<> inline bool is_the_function<psi_SERIAL>(const ex & x)
+{
+ return is_the_function<psi1_SERIAL>(x) || is_the_function<psi2_SERIAL>(x);
+}
+