]> www.ginac.de Git - ginac.git/blobdiff - ginac/inifcns_nstdsums.cpp
G_eval: fix incorrect use of STL iterator.
[ginac.git] / ginac / inifcns_nstdsums.cpp
index bd61fd30e984e7941a48a0ffb1d888f018844ce4..b4105338d329a118ba8317613a1aa5199566a592 100644 (file)
@@ -47,7 +47,7 @@
  */
 
 /*
- *  GiNaC Copyright (C) 1999-2008 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2009 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include <sstream>
-#include <stdexcept>
-#include <vector>
-#include <cln/cln.h>
-
 #include "inifcns.h"
 
 #include "add.h"
 #include "utils.h"
 #include "wildcard.h"
 
+#include <cln/cln.h>
+#include <sstream>
+#include <stdexcept>
+#include <vector>
 
 namespace GiNaC {
 
@@ -210,7 +209,7 @@ void double_Xn()
                        }
                }
                // X_n
-               for (int n=2; n<Xn.size(); ++n) {
+               for (size_t n=2; n<Xn.size(); ++n) {
                        for (int i=xninitsize+1; i<=xend; ++i) {
                                if (i & 1) {
                                        result = 0; // k == 0
@@ -379,15 +378,14 @@ cln::cl_N Li_projection(int n, const cln::cl_N& x, const cln::float_format_t& pr
        }
 }
 
-
 // helper function for classical polylog Li
-numeric Lin_numeric(int n, const numeric& x)
+const cln::cl_N Lin_numeric(const int n, const cln::cl_N& x)
 {
        if (n == 1) {
                // just a log
-               return -cln::log(1-x.to_cl_N());
+               return -cln::log(1-x);
        }
-       if (x.is_zero()) {
+       if (zerop(x)) {
                return 0;
        }
        if (x == 1) {
@@ -398,12 +396,11 @@ numeric Lin_numeric(int n, const numeric& x)
                // [Kol] (2.22)
                return -(1-cln::expt(cln::cl_I(2),1-n)) * cln::zeta(n);
        }
-       if (abs(x.real()) < 0.4 && abs(abs(x)-1) < 0.01) {
-               cln::cl_N x_ = ex_to<numeric>(x).to_cl_N();
-               cln::cl_N result = -cln::expt(cln::log(x_), n-1) * cln::log(1-x_) / cln::factorial(n-1);
+       if (cln::abs(realpart(x)) < 0.4 && cln::abs(cln::abs(x)-1) < 0.01) {
+               cln::cl_N result = -cln::expt(cln::log(x), n-1) * cln::log(1-x) / cln::factorial(n-1);
                for (int j=0; j<n-1; j++) {
-                       result = result + (S_num(n-j-1, 1, 1) - S_num(1, n-j-1, 1-x_))
-                               * cln::expt(cln::log(x_), j) / cln::factorial(j);
+                       result = result + (S_num(n-j-1, 1, 1) - S_num(1, n-j-1, 1-x))
+                               * cln::expt(cln::log(x), j) / cln::factorial(j);
                }
                return result;
        }
@@ -411,11 +408,11 @@ numeric Lin_numeric(int n, const numeric& x)
        // what is the desired float format?
        // first guess: default format
        cln::float_format_t prec = cln::default_float_format;
-       const cln::cl_N value = x.to_cl_N();
+       const cln::cl_N value = x;
        // second guess: the argument's format
-       if (!x.real().is_rational())
+       if (!instanceof(realpart(x), cln::cl_RA_ring))
                prec = cln::float_format(cln::the<cln::cl_F>(cln::realpart(value)));
-       else if (!x.imag().is_rational())
+       else if (!instanceof(imagpart(x), cln::cl_RA_ring))
                prec = cln::float_format(cln::the<cln::cl_F>(cln::imagpart(value)));
        
        // [Kol] (5.15)
@@ -441,7 +438,7 @@ numeric Lin_numeric(int n, const numeric& x)
                cln::cl_N add;
                for (int j=0; j<n-1; j++) {
                        add = add + (1+cln::expt(cln::cl_I(-1),n-j)) * (1-cln::expt(cln::cl_I(2),1-n+j))
-                                   * Lin_numeric(n-j,1).to_cl_N() * cln::expt(cln::log(-value),j) / cln::factorial(j);
+                                   * Lin_numeric(n-j,1) * cln::expt(cln::log(-value),j) / cln::factorial(j);
                }
                result = result - add;
                return result;
@@ -503,33 +500,16 @@ cln::cl_N multipleLi_do_sum(const std::vector<int>& s, const std::vector<cln::cl
 }
 
 
-// converts parameter types and calls multipleLi_do_sum (convenience function for G_numeric)
-cln::cl_N mLi_do_summation(const lst& m, const lst& x)
-{
-       std::vector<int> m_int;
-       std::vector<cln::cl_N> x_cln;
-       for (lst::const_iterator itm = m.begin(), itx = x.begin(); itm != m.end(); ++itm, ++itx) {
-               m_int.push_back(ex_to<numeric>(*itm).to_int());
-               x_cln.push_back(ex_to<numeric>(*itx).to_cl_N());
-       }
-       return multipleLi_do_sum(m_int, x_cln);
-}
-
-
 // forward declaration for Li_eval()
 lst convert_parameter_Li_to_H(const lst& m, const lst& x, ex& pf);
 
 
-// holding dummy-symbols for the G/Li transformations
-std::vector<ex> gsyms;
-
-
 // type used by the transformation functions for G
 typedef std::vector<int> Gparameter;
 
 
 // G_eval1-function for G transformations
-ex G_eval1(int a, int scale)
+ex G_eval1(int a, int scale, const exvector& gsyms)
 {
        if (a != 0) {
                const ex& scs = gsyms[std::abs(scale)];
@@ -546,7 +526,7 @@ ex G_eval1(int a, int scale)
 
 
 // G_eval-function for G transformations
-ex G_eval(const Gparameter& a, int scale)
+ex G_eval(const Gparameter& a, int scale, const exvector& gsyms)
 {
        // check for properties of G
        ex sc = gsyms[std::abs(scale)];
@@ -580,7 +560,7 @@ ex G_eval(const Gparameter& a, int scale)
                for (; it != a.end(); ++it) {
                        short_a.push_back(*it);
                }
-               ex result = G_eval1(a.front(), scale) * G_eval(short_a, scale);
+               ex result = G_eval1(a.front(), scale, gsyms) * G_eval(short_a, scale, gsyms);
                it = short_a.begin();
                for (int i=1; i<count_ones; ++i) {
                        ++it;
@@ -589,23 +569,24 @@ ex G_eval(const Gparameter& a, int scale)
 
                        Gparameter newa;
                        Gparameter::const_iterator it2 = short_a.begin();
-                       for (--it2; it2 != it;) {
-                               ++it2;
+                       for (; it2 != it; ++it2) {
                                newa.push_back(*it2);
                        }
+                       newa.push_back(*it);
                        newa.push_back(a[0]);
+                       it2 = it;
                        ++it2;
                        for (; it2 != short_a.end(); ++it2) {
                                newa.push_back(*it2);   
                        }
-                       result -= G_eval(newa, scale);
+                       result -= G_eval(newa, scale, gsyms);
                }
                return result / count_ones;
        }
 
        // G({1,...,1};y) -> G({1};y)^k / k!
        if (all_ones && a.size() > 1) {
-               return pow(G_eval1(a.front(),scale), count_ones) / factorial(count_ones);
+               return pow(G_eval1(a.front(),scale, gsyms), count_ones) / factorial(count_ones);
        }
 
        // G({0,...,0};y) -> log(y)^k / k!
@@ -698,7 +679,7 @@ Gparameter prepare_pending_integrals(const Gparameter& pending_integrals, int sc
 
 
 // handles trailing zeroes for an otherwise convergent integral
-ex trailing_zeros_G(const Gparameter& a, int scale)
+ex trailing_zeros_G(const Gparameter& a, int scale, const exvector& gsyms)
 {
        bool convergent;
        int depth, trailing_zeros;
@@ -710,23 +691,23 @@ ex trailing_zeros_G(const Gparameter& a, int scale)
        if ((trailing_zeros > 0) && (depth > 0)) {
                ex result;
                Gparameter new_a(a.begin(), a.end()-1);
-               result += G_eval1(0, scale) * trailing_zeros_G(new_a, scale);
+               result += G_eval1(0, scale, gsyms) * trailing_zeros_G(new_a, scale, gsyms);
                for (Gparameter::const_iterator it = a.begin(); it != last; ++it) {
                        Gparameter new_a(a.begin(), it);
                        new_a.push_back(0);
                        new_a.insert(new_a.end(), it, a.end()-1);
-                       result -= trailing_zeros_G(new_a, scale);
+                       result -= trailing_zeros_G(new_a, scale, gsyms);
                }
 
                return result / trailing_zeros;
        } else {
-               return G_eval(a, scale);
+               return G_eval(a, scale, gsyms);
        }
 }
 
 
 // G transformation [VSW] (57),(58)
-ex depth_one_trafo_G(const Gparameter& pending_integrals, const Gparameter& a, int scale)
+ex depth_one_trafo_G(const Gparameter& pending_integrals, const Gparameter& a, int scale, const exvector& gsyms)
 {
        // pendint = ( y1, b1, ..., br )
        //       a = ( 0, ..., 0, amin )
@@ -757,15 +738,21 @@ ex depth_one_trafo_G(const Gparameter& pending_integrals, const Gparameter& a, i
                        result -= I*Pi;
                }
                if (psize) {
-                       result *= trailing_zeros_G(convert_pending_integrals_G(pending_integrals), pending_integrals.front());
+                       result *= trailing_zeros_G(convert_pending_integrals_G(pending_integrals),
+                                                  pending_integrals.front(),
+                                                  gsyms);
                }
                
                // G(y2_{-+}; sr)
-               result += trailing_zeros_G(convert_pending_integrals_G(new_pending_integrals), new_pending_integrals.front());
+               result += trailing_zeros_G(convert_pending_integrals_G(new_pending_integrals),
+                                          new_pending_integrals.front(),
+                                          gsyms);
                
                // G(0; sr)
                new_pending_integrals.back() = 0;
-               result -= trailing_zeros_G(convert_pending_integrals_G(new_pending_integrals), new_pending_integrals.front());
+               result -= trailing_zeros_G(convert_pending_integrals_G(new_pending_integrals),
+                                          new_pending_integrals.front(),
+                                          gsyms);
 
                return result;
        }
@@ -777,14 +764,16 @@ ex depth_one_trafo_G(const Gparameter& pending_integrals, const Gparameter& a, i
        //term zeta_m
        result -= zeta(a.size());
        if (psize) {
-               result *= trailing_zeros_G(convert_pending_integrals_G(pending_integrals), pending_integrals.front());
+               result *= trailing_zeros_G(convert_pending_integrals_G(pending_integrals),
+                                          pending_integrals.front(),
+                                          gsyms);
        }
        
        // term int_0^sr dt/t G_{m-1}( (1/y2)_{+-}; 1/t )
        //    = int_0^sr dt/t G_{m-1}( t_{+-}; y2 )
        Gparameter new_a(a.begin()+1, a.end());
        new_pending_integrals.push_back(0);
-       result -= depth_one_trafo_G(new_pending_integrals, new_a, scale);
+       result -= depth_one_trafo_G(new_pending_integrals, new_a, scale, gsyms);
        
        // term int_0^y2 dt/t G_{m-1}( (1/y2)_{+-}; 1/t )
        //    = int_0^y2 dt/t G_{m-1}( t_{+-}; y2 )
@@ -792,10 +781,12 @@ ex depth_one_trafo_G(const Gparameter& pending_integrals, const Gparameter& a, i
        new_pending_integrals_2.push_back(scale);
        new_pending_integrals_2.push_back(0);
        if (psize) {
-               result += trailing_zeros_G(convert_pending_integrals_G(pending_integrals), pending_integrals.front())
-                         * depth_one_trafo_G(new_pending_integrals_2, new_a, scale);
+               result += trailing_zeros_G(convert_pending_integrals_G(pending_integrals),
+                                          pending_integrals.front(),
+                                          gsyms)
+                         * depth_one_trafo_G(new_pending_integrals_2, new_a, scale, gsyms);
        } else {
-               result += depth_one_trafo_G(new_pending_integrals_2, new_a, scale);
+               result += depth_one_trafo_G(new_pending_integrals_2, new_a, scale, gsyms);
        }
 
        return result;
@@ -804,11 +795,13 @@ ex depth_one_trafo_G(const Gparameter& pending_integrals, const Gparameter& a, i
 
 // forward declaration
 ex shuffle_G(const Gparameter & a0, const Gparameter & a1, const Gparameter & a2,
-            const Gparameter& pendint, const Gparameter& a_old, int scale);
+            const Gparameter& pendint, const Gparameter& a_old, int scale,
+            const exvector& gsyms);
 
 
 // G transformation [VSW]
-ex G_transform(const Gparameter& pendint, const Gparameter& a, int scale)
+ex G_transform(const Gparameter& pendint, const Gparameter& a, int scale,
+              const exvector& gsyms)
 {
        // main recursion routine
        //
@@ -834,10 +827,12 @@ ex G_transform(const Gparameter& pendint, const Gparameter& a, int scale)
                if (a.size() == 0) {
                  result = 1;
                } else {
-                 result = G_eval(a, scale);
+                 result = G_eval(a, scale, gsyms);
                }
                if (pendint.size() > 0) {
-                 result *= trailing_zeros_G(convert_pending_integrals_G(pendint), pendint.front());
+                 result *= trailing_zeros_G(convert_pending_integrals_G(pendint),
+                                            pendint.front(),
+                                            gsyms);
                } 
                return result;
        }
@@ -846,12 +841,12 @@ ex G_transform(const Gparameter& pendint, const Gparameter& a, int scale)
        if (trailing_zeros > 0) {
                ex result;
                Gparameter new_a(a.begin(), a.end()-1);
-               result += G_eval1(0, scale) * G_transform(pendint, new_a, scale);
+               result += G_eval1(0, scale, gsyms) * G_transform(pendint, new_a, scale, gsyms);
                for (Gparameter::const_iterator it = a.begin(); it != firstzero; ++it) {
                        Gparameter new_a(a.begin(), it);
                        new_a.push_back(0);
                        new_a.insert(new_a.end(), it, a.end()-1);
-                       result -= G_transform(pendint, new_a, scale);
+                       result -= G_transform(pendint, new_a, scale, gsyms);
                }
                return result / trailing_zeros;
        }
@@ -859,15 +854,17 @@ ex G_transform(const Gparameter& pendint, const Gparameter& a, int scale)
        // convergence case
        if (convergent) {
                if (pendint.size() > 0) {
-                       return G_eval(convert_pending_integrals_G(pendint), pendint.front()) * G_eval(a, scale);
+                       return G_eval(convert_pending_integrals_G(pendint),
+                                     pendint.front(), gsyms)*
+                               G_eval(a, scale, gsyms);
                } else {
-                       return G_eval(a, scale);
+                       return G_eval(a, scale, gsyms);
                }
        }
 
        // call basic transformation for depth equal one
        if (depth == 1) {
-               return depth_one_trafo_G(pendint, a, scale);
+               return depth_one_trafo_G(pendint, a, scale, gsyms);
        }
 
        // do recursion
@@ -882,9 +879,10 @@ ex G_transform(const Gparameter& pendint, const Gparameter& a, int scale)
                Gparameter a1(a.begin(),min_it+1);
                Gparameter a2(min_it+1,a.end());
 
-               ex result = G_transform(pendint,a2,scale)*G_transform(empty,a1,scale);
+               ex result = G_transform(pendint, a2, scale, gsyms)*
+                       G_transform(empty, a1, scale, gsyms);
 
-               result -= shuffle_G(empty,a1,a2,pendint,a,scale);
+               result -= shuffle_G(empty, a1, a2, pendint, a, scale, gsyms);
                return result;
        }
 
@@ -895,9 +893,10 @@ ex G_transform(const Gparameter& pendint, const Gparameter& a, int scale)
        Gparameter new_pendint = prepare_pending_integrals(pendint, a[min_it_pos]);
        Gparameter new_a = a;
        new_a[min_it_pos] = 0;
-       ex result = G_transform(empty, new_a, scale);
+       ex result = G_transform(empty, new_a, scale, gsyms);
        if (pendint.size() > 0) {
-               result *= trailing_zeros_G(convert_pending_integrals_G(pendint), pendint.front());
+               result *= trailing_zeros_G(convert_pending_integrals_G(pendint),
+                                          pendint.front(), gsyms);
        }
 
        // other terms
@@ -906,29 +905,33 @@ ex G_transform(const Gparameter& pendint, const Gparameter& a, int scale)
        if (changeit != new_a.begin()) {
                // smallest in the middle
                new_pendint.push_back(*changeit);
-               result -= trailing_zeros_G(convert_pending_integrals_G(new_pendint), new_pendint.front())
-                       * G_transform(empty, new_a, scale);
+               result -= trailing_zeros_G(convert_pending_integrals_G(new_pendint),
+                                          new_pendint.front(), gsyms)*
+                       G_transform(empty, new_a, scale, gsyms);
                int buffer = *changeit;
                *changeit = *min_it;
-               result += G_transform(new_pendint, new_a, scale);
+               result += G_transform(new_pendint, new_a, scale, gsyms);
                *changeit = buffer;
                new_pendint.pop_back();
                --changeit;
                new_pendint.push_back(*changeit);
-               result += trailing_zeros_G(convert_pending_integrals_G(new_pendint), new_pendint.front())
-                       * G_transform(empty, new_a, scale);
+               result += trailing_zeros_G(convert_pending_integrals_G(new_pendint),
+                                          new_pendint.front(), gsyms)*
+                       G_transform(empty, new_a, scale, gsyms);
                *changeit = *min_it;
-               result -= G_transform(new_pendint, new_a, scale);
+               result -= G_transform(new_pendint, new_a, scale, gsyms);
        } else {
                // smallest at the front
                new_pendint.push_back(scale);
-               result += trailing_zeros_G(convert_pending_integrals_G(new_pendint), new_pendint.front())
-                       * G_transform(empty, new_a, scale);
+               result += trailing_zeros_G(convert_pending_integrals_G(new_pendint),
+                                          new_pendint.front(), gsyms)*
+                       G_transform(empty, new_a, scale, gsyms);
                new_pendint.back() =  *changeit;
-               result -= trailing_zeros_G(convert_pending_integrals_G(new_pendint), new_pendint.front())
-                       * G_transform(empty, new_a, scale);
+               result -= trailing_zeros_G(convert_pending_integrals_G(new_pendint),
+                                          new_pendint.front(), gsyms)*
+                       G_transform(empty, new_a, scale, gsyms);
                *changeit = *min_it;
-               result += G_transform(new_pendint, new_a, scale);
+               result += G_transform(new_pendint, new_a, scale, gsyms);
        }
        return result;
 }
@@ -937,27 +940,28 @@ ex G_transform(const Gparameter& pendint, const Gparameter& a, int scale)
 // shuffles the two parameter list a1 and a2 and calls G_transform for every term except
 // for the one that is equal to a_old
 ex shuffle_G(const Gparameter & a0, const Gparameter & a1, const Gparameter & a2,
-            const Gparameter& pendint, const Gparameter& a_old, int scale) 
+            const Gparameter& pendint, const Gparameter& a_old, int scale,
+            const exvector& gsyms) 
 {
        if (a1.size()==0 && a2.size()==0) {
                // veto the one configuration we don't want
                if ( a0 == a_old ) return 0;
 
-               return G_transform(pendint,a0,scale);
+               return G_transform(pendint, a0, scale, gsyms);
        }
 
        if (a2.size()==0) {
                Gparameter empty;
                Gparameter aa0 = a0;
                aa0.insert(aa0.end(),a1.begin(),a1.end());
-               return shuffle_G(aa0,empty,empty,pendint,a_old,scale);
+               return shuffle_G(aa0, empty, empty, pendint, a_old, scale, gsyms);
        }
 
        if (a1.size()==0) {
                Gparameter empty;
                Gparameter aa0 = a0;
                aa0.insert(aa0.end(),a2.begin(),a2.end());
-               return shuffle_G(aa0,empty,empty,pendint,a_old,scale);
+               return shuffle_G(aa0, empty, empty, pendint, a_old, scale, gsyms);
        }
 
        Gparameter a1_removed(a1.begin()+1,a1.end());
@@ -969,202 +973,232 @@ ex shuffle_G(const Gparameter & a0, const Gparameter & a1, const Gparameter & a2
        a01.push_back( a1[0] );
        a02.push_back( a2[0] );
 
-       return shuffle_G(a01,a1_removed,a2,pendint,a_old,scale)
-            + shuffle_G(a02,a1,a2_removed,pendint,a_old,scale);
+       return shuffle_G(a01, a1_removed, a2, pendint, a_old, scale, gsyms)
+            + shuffle_G(a02, a1, a2_removed, pendint, a_old, scale, gsyms);
 }
 
-
 // handles the transformations and the numerical evaluation of G
 // the parameter x, s and y must only contain numerics
-ex G_numeric(const lst& x, const lst& s, const ex& y)
+static cln::cl_N
+G_numeric(const std::vector<cln::cl_N>& x, const std::vector<int>& s,
+         const cln::cl_N& y);
+
+// do acceleration transformation (hoelder convolution [BBB])
+// the parameter x, s and y must only contain numerics
+static cln::cl_N
+G_do_hoelder(std::vector<cln::cl_N> x, /* yes, it's passed by value */
+            const std::vector<int>& s, const cln::cl_N& y)
 {
-       // check for convergence and necessary accelerations
-       bool need_trafo = false;
-       bool need_hoelder = false;
-       int depth = 0;
-       for (lst::const_iterator it = x.begin(); it != x.end(); ++it) {
-               if (!(*it).is_zero()) {
-                       ++depth;
-                       if (abs(*it) - y < -pow(10,-Digits+1)) {
-                               need_trafo = true;
+       cln::cl_N result;
+       const std::size_t size = x.size();
+       for (std::size_t i = 0; i < size; ++i)
+               x[i] = x[i]/y;
+
+       for (std::size_t r = 0; r <= size; ++r) {
+               cln::cl_N buffer(1 & r ? -1 : 1);
+               cln::cl_RA p(2);
+               bool adjustp;
+               do {
+                       adjustp = false;
+                       for (std::size_t i = 0; i < size; ++i) {
+                               if (x[i] == cln::cl_RA(1)/p) {
+                                       p = p/2 + cln::cl_RA(3)/2;
+                                       adjustp = true;
+                                       continue;
+                               }
                        }
-                       if (abs((abs(*it) - y)/y) < 0.01) {
-                               need_hoelder = true;
+               } while (adjustp);
+               cln::cl_RA q = p/(p-1);
+               std::vector<cln::cl_N> qlstx;
+               std::vector<int> qlsts;
+               for (std::size_t j = r; j >= 1; --j) {
+                       qlstx.push_back(cln::cl_N(1) - x[j-1]);
+                       if (instanceof(x[j-1], cln::cl_R_ring) &&
+                           realpart(x[j-1]) > 1 && realpart(x[j-1]) <= 2) {
+                               qlsts.push_back(s[j-1]);
+                       } else {
+                               qlsts.push_back(-s[j-1]);
                        }
                }
-       }
-       if (x.op(x.nops()-1).is_zero()) {
-               need_trafo = true;
-       }
-       if (depth == 1 && x.nops() == 2 && !need_trafo) {
-               return -Li(x.nops(), y / x.op(x.nops()-1)).evalf();
-       }
-       
-       // do acceleration transformation (hoelder convolution [BBB])
-       if (need_hoelder) {
-               
-               ex result;
-               const int size = x.nops();
-               lst newx;
-               for (lst::const_iterator it = x.begin(); it != x.end(); ++it) {
-                       newx.append(*it / y);
+               if (qlstx.size() > 0) {
+                       buffer = buffer*G_numeric(qlstx, qlsts, 1/q);
                }
-               
-               for (int r=0; r<=size; ++r) {
-                       ex buffer = pow(-1, r);
-                       ex p = 2;
-                       bool adjustp;
-                       do {
-                               adjustp = false;
-                               for (lst::const_iterator it = newx.begin(); it != newx.end(); ++it) {
-                                       if (*it == 1/p) {
-                                               p += (3-p)/2; 
-                                               adjustp = true;
-                                               continue;
-                                       }
-                               }
-                       } while (adjustp);
-                       ex q = p / (p-1);
-                       lst qlstx;
-                       lst qlsts;
-                       for (int j=r; j>=1; --j) {
-                               qlstx.append(1-newx.op(j-1));
-                               if (newx.op(j-1).info(info_flags::real) && newx.op(j-1) > 1 && newx.op(j-1) <= 2) {
-                                       qlsts.append( s.op(j-1));
-                               } else {
-                                       qlsts.append( -s.op(j-1));
-                               }
-                       }
-                       if (qlstx.nops() > 0) {
-                               buffer *= G_numeric(qlstx, qlsts, 1/q);
-                       }
-                       lst plstx;
-                       lst plsts;
-                       for (int j=r+1; j<=size; ++j) {
-                               plstx.append(newx.op(j-1));
-                               plsts.append(s.op(j-1));
-                       }
-                       if (plstx.nops() > 0) {
-                               buffer *= G_numeric(plstx, plsts, 1/p);
-                       }
-                       result += buffer;
+               std::vector<cln::cl_N> plstx;
+               std::vector<int> plsts;
+               for (std::size_t j = r+1; j <= size; ++j) {
+                       plstx.push_back(x[j-1]);
+                       plsts.push_back(s[j-1]);
                }
-               return result;
+               if (plstx.size() > 0) {
+                       buffer = buffer*G_numeric(plstx, plsts, 1/p);
+               }
+               result = result + buffer;
        }
-       
-       // convergence transformation
-       if (need_trafo) {
-
-               // sort (|x|<->position) to determine indices
-               std::multimap<ex,int> sortmap;
-               int size = 0;
-               for (int i=0; i<x.nops(); ++i) {
-                       if (!x[i].is_zero()) {
-                               sortmap.insert(std::pair<ex,int>(abs(x[i]), i));
-                               ++size;
-                       }
-               }
-               // include upper limit (scale)
-               sortmap.insert(std::pair<ex,int>(abs(y), x.nops()));
-
-               // generate missing dummy-symbols
-               int i = 1;
-               gsyms.clear();
-               gsyms.push_back(symbol("GSYMS_ERROR"));
-               ex lastentry;
-               for (std::multimap<ex,int>::const_iterator it = sortmap.begin(); it != sortmap.end(); ++it) {
-                       if (it != sortmap.begin()) {
-                               if (it->second < x.nops()) {
-                                       if (x[it->second] == lastentry) {
-                                               gsyms.push_back(gsyms.back());
-                                               continue;
-                                       }
-                               } else {
-                                       if (y == lastentry) {
-                                               gsyms.push_back(gsyms.back());
-                                               continue;
-                                       }
+       return result;
+}
+
+// convergence transformation, used for numerical evaluation of G function.
+// the parameter x, s and y must only contain numerics
+static cln::cl_N
+G_do_trafo(const std::vector<cln::cl_N>& x, const std::vector<int>& s,
+          const cln::cl_N& y)
+{
+       // sort (|x|<->position) to determine indices
+       typedef std::multimap<cln::cl_R, std::size_t> sortmap_t;
+       sortmap_t sortmap;
+       std::size_t size = 0;
+       for (std::size_t i = 0; i < x.size(); ++i) {
+               if (!zerop(x[i])) {
+                       sortmap.insert(std::make_pair(abs(x[i]), i));
+                       ++size;
+               }
+       }
+       // include upper limit (scale)
+       sortmap.insert(std::make_pair(abs(y), x.size()));
+
+       // generate missing dummy-symbols
+       int i = 1;
+       // holding dummy-symbols for the G/Li transformations
+       exvector gsyms;
+       gsyms.push_back(symbol("GSYMS_ERROR"));
+       cln::cl_N lastentry(0);
+       for (sortmap_t::const_iterator it = sortmap.begin(); it != sortmap.end(); ++it) {
+               if (it != sortmap.begin()) {
+                       if (it->second < x.size()) {
+                               if (x[it->second] == lastentry) {
+                                       gsyms.push_back(gsyms.back());
+                                       continue;
                                }
-                       }
-                       std::ostringstream os;
-                       os << "a" << i;
-                       gsyms.push_back(symbol(os.str()));
-                       ++i;
-                       if (it->second < x.nops()) {
-                               lastentry = x[it->second];
                        } else {
-                               lastentry = y;
+                               if (y == lastentry) {
+                                       gsyms.push_back(gsyms.back());
+                                       continue;
+                               }
                        }
                }
+               std::ostringstream os;
+               os << "a" << i;
+               gsyms.push_back(symbol(os.str()));
+               ++i;
+               if (it->second < x.size()) {
+                       lastentry = x[it->second];
+               } else {
+                       lastentry = y;
+               }
+       }
 
-               // fill position data according to sorted indices and prepare substitution list
-               Gparameter a(x.nops());
-               lst subslst;
-               int pos = 1;
-               int scale;
-               for (std::multimap<ex,int>::const_iterator it = sortmap.begin(); it != sortmap.end(); ++it) {
-                       if (it->second < x.nops()) {
-                               if (s[it->second] > 0) {
-                                       a[it->second] = pos;
-                               } else {
-                                       a[it->second] = -pos;
-                               }
-                               subslst.append(gsyms[pos] == x[it->second]);
+       // fill position data according to sorted indices and prepare substitution list
+       Gparameter a(x.size());
+       exmap subslst;
+       std::size_t pos = 1;
+       int scale = pos;
+       for (sortmap_t::const_iterator it = sortmap.begin(); it != sortmap.end(); ++it) {
+               if (it->second < x.size()) {
+                       if (s[it->second] > 0) {
+                               a[it->second] = pos;
                        } else {
-                               scale = pos;
-                               subslst.append(gsyms[pos] == y);
+                               a[it->second] = -int(pos);
                        }
-                       ++pos;
+                       subslst[gsyms[pos]] = numeric(x[it->second]);
+               } else {
+                       scale = pos;
+                       subslst[gsyms[pos]] = numeric(y);
                }
+               ++pos;
+       }
 
-               // do transformation
-               Gparameter pendint;
-               ex result = G_transform(pendint, a, scale);
-               // replace dummy symbols with their values
-               result = result.eval().expand();
-               result = result.subs(subslst).evalf();
-               
-               return result;
+       // do transformation
+       Gparameter pendint;
+       ex result = G_transform(pendint, a, scale, gsyms);
+       // replace dummy symbols with their values
+       result = result.eval().expand();
+       result = result.subs(subslst).evalf();
+       if (!is_a<numeric>(result))
+               throw std::logic_error("G_do_trafo: G_transform returned non-numeric result");
+       
+       cln::cl_N ret = ex_to<numeric>(result).to_cl_N();
+       return ret;
+}
+
+// handles the transformations and the numerical evaluation of G
+// the parameter x, s and y must only contain numerics
+static cln::cl_N
+G_numeric(const std::vector<cln::cl_N>& x, const std::vector<int>& s,
+         const cln::cl_N& y)
+{
+       // check for convergence and necessary accelerations
+       bool need_trafo = false;
+       bool need_hoelder = false;
+       std::size_t depth = 0;
+       for (std::size_t i = 0; i < x.size(); ++i) {
+               if (!zerop(x[i])) {
+                       ++depth;
+                       const cln::cl_N x_y = abs(x[i]) - y;
+                       if (instanceof(x_y, cln::cl_R_ring) &&
+                           realpart(x_y) < cln::least_negative_float(cln::float_format(Digits - 2)))
+                               need_trafo = true;
+
+                       if (abs(abs(x[i]/y) - 1) < 0.01)
+                               need_hoelder = true;
+               }
        }
+       if (zerop(x[x.size() - 1]))
+               need_trafo = true;
+
+       if (depth == 1 && x.size() == 2 && !need_trafo)
+               return - Li_projection(2, y/x[1], cln::float_format(Digits));
+       
+       // do acceleration transformation (hoelder convolution [BBB])
+       if (need_hoelder)
+               return G_do_hoelder(x, s, y);
+       
+       // convergence transformation
+       if (need_trafo)
+               return G_do_trafo(x, s, y);
 
        // do summation
-       lst newx;
-       lst m;
+       std::vector<cln::cl_N> newx;
+       newx.reserve(x.size());
+       std::vector<int> m;
+       m.reserve(x.size());
        int mcount = 1;
-       ex sign = 1;
-       ex factor = y;
-       for (lst::const_iterator it = x.begin(); it != x.end(); ++it) {
-               if ((*it).is_zero()) {
+       int sign = 1;
+       cln::cl_N factor = y;
+       for (std::size_t i = 0; i < x.size(); ++i) {
+               if (zerop(x[i])) {
                        ++mcount;
                } else {
-                       newx.append(factor / (*it));
-                       factor = *it;
-                       m.append(mcount);
+                       newx.push_back(factor/x[i]);
+                       factor = x[i];
+                       m.push_back(mcount);
                        mcount = 1;
                        sign = -sign;
                }
        }
 
-       return sign * numeric(mLi_do_summation(m, newx));
+       return sign*multipleLi_do_sum(m, newx);
 }
 
 
 ex mLi_numeric(const lst& m, const lst& x)
 {
        // let G_numeric do the transformation
-       lst newx;
-       lst s;
-       ex factor = 1;
+       std::vector<cln::cl_N> newx;
+       newx.reserve(x.nops());
+       std::vector<int> s;
+       s.reserve(x.nops());
+       cln::cl_N factor(1);
        for (lst::const_iterator itm = m.begin(), itx = x.begin(); itm != m.end(); ++itm, ++itx) {
                for (int i = 1; i < *itm; ++i) {
-                       newx.append(0);
-                       s.append(1);
+                       newx.push_back(cln::cl_N(0));
+                       s.push_back(1);
                }
-               newx.append(factor / *itx);
-               factor /= *itx;
-               s.append(1);
+               const cln::cl_N xi = ex_to<numeric>(*itx).to_cl_N();
+               newx.push_back(factor/xi);
+               factor = factor/xi;
+               s.push_back(1);
        }
-       return pow(-1, m.nops()) * G_numeric(newx, s, _ex1);
+       return numeric(cln::cl_N(1 & m.nops() ? - 1 : 1)*G_numeric(newx, s, cln::cl_N(1)));
 }
 
 
@@ -1192,7 +1226,8 @@ static ex G2_evalf(const ex& x_, const ex& y)
        if (x.op(0) == y) {
                return G(x_, y).hold();
        }
-       lst s;
+       std::vector<int> s;
+       s.reserve(x.nops());
        bool all_zero = true;
        for (lst::const_iterator it = x.begin(); it != x.end(); ++it) {
                if (!(*it).info(info_flags::numeric)) {
@@ -1201,12 +1236,22 @@ static ex G2_evalf(const ex& x_, const ex& y)
                if (*it != _ex0) {
                        all_zero = false;
                }
-               s.append(+1);
+               if ( !ex_to<numeric>(*it).is_real() && ex_to<numeric>(*it).imag() < 0 ) {
+                       s.push_back(-1);
+               }
+               else {
+                       s.push_back(1);
+               }
        }
        if (all_zero) {
                return pow(log(y), x.nops()) / factorial(x.nops());
        }
-       return G_numeric(x, s, y);
+       std::vector<cln::cl_N> xv;
+       xv.reserve(x.nops());
+       for (lst::const_iterator it = x.begin(); it != x.end(); ++it)
+               xv.push_back(ex_to<numeric>(*it).to_cl_N());
+       cln::cl_N result = G_numeric(xv, s, ex_to<numeric>(y).to_cl_N());
+       return numeric(result);
 }
 
 
@@ -1224,7 +1269,8 @@ static ex G2_eval(const ex& x_, const ex& y)
        if (x.op(0) == y) {
                return G(x_, y).hold();
        }
-       lst s;
+       std::vector<int> s;
+       s.reserve(x.nops());
        bool all_zero = true;
        bool crational = true;
        for (lst::const_iterator it = x.begin(); it != x.end(); ++it) {
@@ -1237,7 +1283,12 @@ static ex G2_eval(const ex& x_, const ex& y)
                if (*it != _ex0) {
                        all_zero = false;
                }
-               s.append(+1);
+               if ( !ex_to<numeric>(*it).is_real() && ex_to<numeric>(*it).imag() < 0 ) {
+                       s.push_back(-1);
+               }
+               else {
+                       s.push_back(+1);
+               }
        }
        if (all_zero) {
                return pow(log(y), x.nops()) / factorial(x.nops());
@@ -1248,7 +1299,12 @@ static ex G2_eval(const ex& x_, const ex& y)
        if (crational) {
                return G(x_, y).hold();
        }
-       return G_numeric(x, s, y);
+       std::vector<cln::cl_N> xv;
+       xv.reserve(x.nops());
+       for (lst::const_iterator it = x.begin(); it != x.end(); ++it)
+               xv.push_back(ex_to<numeric>(*it).to_cl_N());
+       cln::cl_N result = G_numeric(xv, s, ex_to<numeric>(y).to_cl_N());
+       return numeric(result);
 }
 
 
@@ -1278,7 +1334,8 @@ static ex G3_evalf(const ex& x_, const ex& s_, const ex& y)
        if (x.op(0) == y) {
                return G(x_, s_, y).hold();
        }
-       lst sn;
+       std::vector<int> sn;
+       sn.reserve(s.nops());
        bool all_zero = true;
        for (lst::const_iterator itx = x.begin(), its = s.begin(); itx != x.end(); ++itx, ++its) {
                if (!(*itx).info(info_flags::numeric)) {
@@ -1290,16 +1347,32 @@ static ex G3_evalf(const ex& x_, const ex& s_, const ex& y)
                if (*itx != _ex0) {
                        all_zero = false;
                }
-               if (*its >= 0) {
-                       sn.append(+1);
-               } else {
-                       sn.append(-1);
+               if ( ex_to<numeric>(*itx).is_real() ) {
+                       if ( *its >= 0 ) {
+                               sn.push_back(1);
+                       }
+                       else {
+                               sn.push_back(-1);
+                       }
+               }
+               else {
+                       if ( ex_to<numeric>(*itx).imag() > 0 ) {
+                               sn.push_back(1);
+                       }
+                       else {
+                               sn.push_back(-1);
+                       }
                }
        }
        if (all_zero) {
                return pow(log(y), x.nops()) / factorial(x.nops());
        }
-       return G_numeric(x, sn, y);
+       std::vector<cln::cl_N> xn;
+       xn.reserve(x.nops());
+       for (lst::const_iterator it = x.begin(); it != x.end(); ++it)
+               xn.push_back(ex_to<numeric>(*it).to_cl_N());
+       cln::cl_N result = G_numeric(xn, sn, ex_to<numeric>(y).to_cl_N());
+       return numeric(result);
 }
 
 
@@ -1321,7 +1394,8 @@ static ex G3_eval(const ex& x_, const ex& s_, const ex& y)
        if (x.op(0) == y) {
                return G(x_, s_, y).hold();
        }
-       lst sn;
+       std::vector<int> sn;
+       sn.reserve(s.nops());
        bool all_zero = true;
        bool crational = true;
        for (lst::const_iterator itx = x.begin(), its = s.begin(); itx != x.end(); ++itx, ++its) {
@@ -1337,10 +1411,21 @@ static ex G3_eval(const ex& x_, const ex& s_, const ex& y)
                if (*itx != _ex0) {
                        all_zero = false;
                }
-               if (*its >= 0) {
-                       sn.append(+1);
-               } else {
-                       sn.append(-1);
+               if ( ex_to<numeric>(*itx).is_real() ) {
+                       if ( *its >= 0 ) {
+                               sn.push_back(1);
+                       }
+                       else {
+                               sn.push_back(-1);
+                       }
+               }
+               else {
+                       if ( ex_to<numeric>(*itx).imag() > 0 ) {
+                               sn.push_back(1);
+                       }
+                       else {
+                               sn.push_back(-1);
+                       }
                }
        }
        if (all_zero) {
@@ -1352,7 +1437,12 @@ static ex G3_eval(const ex& x_, const ex& s_, const ex& y)
        if (crational) {
                return G(x_, s_, y).hold();
        }
-       return G_numeric(x, sn, y);
+       std::vector<cln::cl_N> xn;
+       xn.reserve(x.nops());
+       for (lst::const_iterator it = x.begin(); it != x.end(); ++it)
+               xn.push_back(ex_to<numeric>(*it).to_cl_N());
+       cln::cl_N result = G_numeric(xn, sn, ex_to<numeric>(y).to_cl_N());
+       return numeric(result);
 }
 
 
@@ -1380,12 +1470,18 @@ static ex Li_evalf(const ex& m_, const ex& x_)
        // classical polylogs
        if (m_.info(info_flags::posint)) {
                if (x_.info(info_flags::numeric)) {
-                       return Lin_numeric(ex_to<numeric>(m_).to_int(), ex_to<numeric>(x_));
+                       int m__ = ex_to<numeric>(m_).to_int();
+                       const cln::cl_N x__ = ex_to<numeric>(x_).to_cl_N();
+                       const cln::cl_N result = Lin_numeric(m__, x__);
+                       return numeric(result);
                } else {
                        // try to numerically evaluate second argument
                        ex x_val = x_.evalf();
                        if (x_val.info(info_flags::numeric)) {
-                               return Lin_numeric(ex_to<numeric>(m_).to_int(), ex_to<numeric>(x_val));
+                               int m__ = ex_to<numeric>(m_).to_int();
+                               const cln::cl_N x__ = ex_to<numeric>(x_val).to_cl_N();
+                               const cln::cl_N result = Lin_numeric(m__, x__);
+                               return numeric(result);
                        }
                }
        }
@@ -1499,7 +1595,10 @@ static ex Li_eval(const ex& m_, const ex& x_)
                }
        }
        if (m_.info(info_flags::posint) && x_.info(info_flags::numeric) && !x_.info(info_flags::crational)) {
-               return Lin_numeric(ex_to<numeric>(m_).to_int(), ex_to<numeric>(x_));
+               int m__ = ex_to<numeric>(m_).to_int();
+               const cln::cl_N x__ = ex_to<numeric>(x_).to_cl_N();
+               const cln::cl_N result = Lin_numeric(m__, x__);
+               return numeric(result);
        }
 
        return Li(m_, x_).hold();
@@ -2182,7 +2281,7 @@ bool convert_parameter_H_to_Li(const lst& l, lst& m, lst& s, ex& pf)
                }
        }
        if (has_negative_parameters) {
-               for (int i=0; i<m.nops(); i++) {
+               for (std::size_t i=0; i<m.nops(); i++) {
                        if (m.op(i) < 0) {
                                m.let_op(i) = -m.op(i);
                                s.append(-1);
@@ -2222,7 +2321,7 @@ struct map_trafo_H_convert_to_Li : public map_function
                                        s.let_op(0) = s.op(0) * arg;
                                        return pf * Li(m, s).hold();
                                } else {
-                                       for (int i=0; i<m.nops(); i++) {
+                                       for (std::size_t i=0; i<m.nops(); i++) {
                                                s.append(1);
                                        }
                                        s.let_op(0) = s.op(0) * arg;
@@ -2304,7 +2403,7 @@ struct map_trafo_H_reduce_trailing_zeros : public map_function
                                        
                                        //
                                        parameter.remove_last();
-                                       int lastentry = parameter.nops();
+                                       std::size_t lastentry = parameter.nops();
                                        while ((lastentry > 0) && (parameter[lastentry-1] == 0)) {
                                                lastentry--;
                                        }
@@ -2393,9 +2492,9 @@ ex trafo_H_mult(const ex& h1, const ex& h2)
                        hlong = h2.op(0).op(0);
                }
        }
-       for (int i=0; i<=hlong.nops(); i++) {
+       for (std::size_t i=0; i<=hlong.nops(); i++) {
                lst newparameter;
-               int j=0;
+               std::size_t j=0;
                for (; j<i; j++) {
                        newparameter.append(hlong[j]);
                }
@@ -2423,7 +2522,7 @@ struct map_trafo_H_mult : public map_function
                        ex result = 1;
                        ex firstH;
                        lst Hlst;
-                       for (int pos=0; pos<e.nops(); pos++) {
+                       for (std::size_t pos=0; pos<e.nops(); pos++) {
                                if (is_a<power>(e.op(pos)) && is_a<function>(e.op(pos).op(0))) {
                                        std::string name = ex_to<function>(e.op(pos).op(0)).get_name();
                                        if (name == "H") {
@@ -2457,7 +2556,7 @@ struct map_trafo_H_mult : public map_function
                        if (Hlst.nops() > 0) {
                                ex buffer = trafo_H_mult(firstH, Hlst.op(0));
                                result *= buffer;
-                               for (int i=1; i<Hlst.nops(); i++) {
+                               for (std::size_t i=1; i<Hlst.nops(); i++) {
                                        result *= Hlst.op(i);
                                }
                                result = result.expand();
@@ -2485,7 +2584,7 @@ ex trafo_H_1tx_prepend_zero(const ex& e, const ex& arg)
        if (name == "H") {
                h = e;
        } else {
-               for (int i=0; i<e.nops(); i++) {
+               for (std::size_t i=0; i<e.nops(); i++) {
                        if (is_a<function>(e.op(i))) {
                                std::string name = ex_to<function>(e.op(i)).get_name();
                                if (name == "H") {
@@ -2517,7 +2616,7 @@ ex trafo_H_prepend_one(const ex& e, const ex& arg)
        if (name == "H") {
                h = e;
        } else {
-               for (int i=0; i<e.nops(); i++) {
+               for (std::size_t i=0; i<e.nops(); i++) {
                        if (is_a<function>(e.op(i))) {
                                std::string name = ex_to<function>(e.op(i)).get_name();
                                if (name == "H") {
@@ -2548,7 +2647,7 @@ ex trafo_H_1tx_prepend_minusone(const ex& e, const ex& arg)
        if (name == "H") {
                h = e;
        } else {
-               for (int i=0; i<e.nops(); i++) {
+               for (std::size_t i=0; i<e.nops(); i++) {
                        if (is_a<function>(e.op(i))) {
                                std::string name = ex_to<function>(e.op(i)).get_name();
                                if (name == "H") {
@@ -2581,7 +2680,7 @@ ex trafo_H_1mxt1px_prepend_minusone(const ex& e, const ex& arg)
        if (name == "H") {
                h = e;
        } else {
-               for (int i=0; i<e.nops(); i++) {
+               for (std::size_t i = 0; i < e.nops(); i++) {
                        if (is_a<function>(e.op(i))) {
                                std::string name = ex_to<function>(e.op(i)).get_name();
                                if (name == "H") {
@@ -2612,7 +2711,7 @@ ex trafo_H_1mxt1px_prepend_one(const ex& e, const ex& arg)
        if (name == "H") {
                h = e;
        } else {
-               for (int i=0; i<e.nops(); i++) {
+               for (std::size_t i = 0; i < e.nops(); i++) {
                        if (is_a<function>(e.op(i))) {
                                std::string name = ex_to<function>(e.op(i)).get_name();
                                if (name == "H") {
@@ -2650,7 +2749,7 @@ struct map_trafo_H_1mx : public map_function
                                // special cases if all parameters are either 0, 1 or -1
                                bool allthesame = true;
                                if (parameter.op(0) == 0) {
-                                       for (int i=1; i<parameter.nops(); i++) {
+                                       for (std::size_t i = 1; i < parameter.nops(); i++) {
                                                if (parameter.op(i) != 0) {
                                                        allthesame = false;
                                                        break;
@@ -2666,7 +2765,7 @@ struct map_trafo_H_1mx : public map_function
                                } else if (parameter.op(0) == -1) {
                                        throw std::runtime_error("map_trafo_H_1mx: cannot handle weights equal -1!");
                                } else {
-                                       for (int i=1; i<parameter.nops(); i++) {
+                                       for (std::size_t i = 1; i < parameter.nops(); i++) {
                                                if (parameter.op(i) != 1) {
                                                        allthesame = false;
                                                        break;
@@ -2692,7 +2791,7 @@ struct map_trafo_H_1mx : public map_function
                                        map_trafo_H_1mx recursion;
                                        ex buffer = recursion(H(newparameter, arg).hold());
                                        if (is_a<add>(buffer)) {
-                                               for (int i=0; i<buffer.nops(); i++) {
+                                               for (std::size_t i = 0; i < buffer.nops(); i++) {
                                                        res -= trafo_H_prepend_one(buffer.op(i), arg);
                                                }
                                        } else {
@@ -2706,13 +2805,13 @@ struct map_trafo_H_1mx : public map_function
                                        map_trafo_H_1mx recursion;
                                        map_trafo_H_mult unify;
                                        ex res = H(lst(1), arg).hold() * H(newparameter, arg).hold();
-                                       int firstzero = 0;
+                                       std::size_t firstzero = 0;
                                        while (parameter.op(firstzero) == 1) {
                                                firstzero++;
                                        }
-                                       for (int i=firstzero-1; i<parameter.nops()-1; i++) {
+                                       for (std::size_t i = firstzero-1; i < parameter.nops()-1; i++) {
                                                lst newparameter;
-                                               int j=0;
+                                               std::size_t j=0;
                                                for (; j<=i; j++) {
                                                        newparameter.append(parameter[j+1]);
                                                }
@@ -2751,7 +2850,7 @@ struct map_trafo_H_1overx : public map_function
                                // special cases if all parameters are either 0, 1 or -1
                                bool allthesame = true;
                                if (parameter.op(0) == 0) {
-                                       for (int i=1; i<parameter.nops(); i++) {
+                                       for (std::size_t i = 1; i < parameter.nops(); i++) {
                                                if (parameter.op(i) != 0) {
                                                        allthesame = false;
                                                        break;
@@ -2761,7 +2860,7 @@ struct map_trafo_H_1overx : public map_function
                                                return pow(-1, parameter.nops()) * H(parameter, 1/arg).hold();
                                        }
                                } else if (parameter.op(0) == -1) {
-                                       for (int i=1; i<parameter.nops(); i++) {
+                                       for (std::size_t i = 1; i < parameter.nops(); i++) {
                                                if (parameter.op(i) != -1) {
                                                        allthesame = false;
                                                        break;
@@ -2773,7 +2872,7 @@ struct map_trafo_H_1overx : public map_function
                                                       / factorial(parameter.nops())).expand());
                                        }
                                } else {
-                                       for (int i=1; i<parameter.nops(); i++) {
+                                       for (std::size_t i = 1; i < parameter.nops(); i++) {
                                                if (parameter.op(i) != 1) {
                                                        allthesame = false;
                                                        break;
@@ -2796,7 +2895,7 @@ struct map_trafo_H_1overx : public map_function
                                        map_trafo_H_1overx recursion;
                                        ex buffer = recursion(H(newparameter, arg).hold());
                                        if (is_a<add>(buffer)) {
-                                               for (int i=0; i<buffer.nops(); i++) {
+                                               for (std::size_t i = 0; i < buffer.nops(); i++) {
                                                        res += trafo_H_1tx_prepend_zero(buffer.op(i), arg);
                                                }
                                        } else {
@@ -2811,7 +2910,7 @@ struct map_trafo_H_1overx : public map_function
                                        map_trafo_H_1overx recursion;
                                        ex buffer = recursion(H(newparameter, arg).hold());
                                        if (is_a<add>(buffer)) {
-                                               for (int i=0; i<buffer.nops(); i++) {
+                                               for (std::size_t i = 0; i < buffer.nops(); i++) {
                                                        res += trafo_H_1tx_prepend_zero(buffer.op(i), arg) - trafo_H_1tx_prepend_minusone(buffer.op(i), arg);
                                                }
                                        } else {
@@ -2825,13 +2924,13 @@ struct map_trafo_H_1overx : public map_function
                                        map_trafo_H_1overx recursion;
                                        map_trafo_H_mult unify;
                                        ex res = H(lst(1), arg).hold() * H(newparameter, arg).hold();
-                                       int firstzero = 0;
+                                       std::size_t firstzero = 0;
                                        while (parameter.op(firstzero) == 1) {
                                                firstzero++;
                                        }
-                                       for (int i=firstzero-1; i<parameter.nops()-1; i++) {
+                                       for (std::size_t i = firstzero-1; i < parameter.nops() - 1; i++) {
                                                lst newparameter;
-                                               int j=0;
+                                               std::size_t j = 0;
                                                for (; j<=i; j++) {
                                                        newparameter.append(parameter[j+1]);
                                                }
@@ -2872,7 +2971,7 @@ struct map_trafo_H_1mxt1px : public map_function
                                // special cases if all parameters are either 0, 1 or -1
                                bool allthesame = true;
                                if (parameter.op(0) == 0) {
-                                       for (int i=1; i<parameter.nops(); i++) {
+                                       for (std::size_t i = 1; i < parameter.nops(); i++) {
                                                if (parameter.op(i) != 0) {
                                                        allthesame = false;
                                                        break;
@@ -2884,7 +2983,7 @@ struct map_trafo_H_1mxt1px : public map_function
                                                       / factorial(parameter.nops())).expand());
                                        }
                                } else if (parameter.op(0) == -1) {
-                                       for (int i=1; i<parameter.nops(); i++) {
+                                       for (std::size_t i = 1; i < parameter.nops(); i++) {
                                                if (parameter.op(i) != -1) {
                                                        allthesame = false;
                                                        break;
@@ -2896,7 +2995,7 @@ struct map_trafo_H_1mxt1px : public map_function
                                                       / factorial(parameter.nops())).expand());
                                        }
                                } else {
-                                       for (int i=1; i<parameter.nops(); i++) {
+                                       for (std::size_t i = 1; i < parameter.nops(); i++) {
                                                if (parameter.op(i) != 1) {
                                                        allthesame = false;
                                                        break;
@@ -2919,7 +3018,7 @@ struct map_trafo_H_1mxt1px : public map_function
                                        map_trafo_H_1mxt1px recursion;
                                        ex buffer = recursion(H(newparameter, arg).hold());
                                        if (is_a<add>(buffer)) {
-                                               for (int i=0; i<buffer.nops(); i++) {
+                                               for (std::size_t i = 0; i < buffer.nops(); i++) {
                                                        res -= trafo_H_1mxt1px_prepend_one(buffer.op(i), arg) + trafo_H_1mxt1px_prepend_minusone(buffer.op(i), arg);
                                                }
                                        } else {
@@ -2934,7 +3033,7 @@ struct map_trafo_H_1mxt1px : public map_function
                                        map_trafo_H_1mxt1px recursion;
                                        ex buffer = recursion(H(newparameter, arg).hold());
                                        if (is_a<add>(buffer)) {
-                                               for (int i=0; i<buffer.nops(); i++) {
+                                               for (std::size_t i = 0; i < buffer.nops(); i++) {
                                                        res -= trafo_H_1mxt1px_prepend_minusone(buffer.op(i), arg);
                                                }
                                        } else {
@@ -2948,13 +3047,13 @@ struct map_trafo_H_1mxt1px : public map_function
                                        map_trafo_H_1mxt1px recursion;
                                        map_trafo_H_mult unify;
                                        ex res = H(lst(1), arg).hold() * H(newparameter, arg).hold();
-                                       int firstzero = 0;
+                                       std::size_t firstzero = 0;
                                        while (parameter.op(firstzero) == 1) {
                                                firstzero++;
                                        }
-                                       for (int i=firstzero-1; i<parameter.nops()-1; i++) {
+                                       for (std::size_t i = firstzero - 1; i < parameter.nops() - 1; i++) {
                                                lst newparameter;
-                                               int j=0;
+                                               std::size_t j=0;
                                                for (; j<=i; j++) {
                                                        newparameter.append(parameter[j+1]);
                                                }
@@ -3028,7 +3127,7 @@ static ex H_evalf(const ex& x1, const ex& x2)
                        }
                }
 
-               for (int i=0; i<x1.nops(); i++) {
+               for (std::size_t i = 0; i < x1.nops(); i++) {
                        if (!x1.op(i).info(info_flags::integer)) {
                                return H(x1, x2).hold();
                        }
@@ -3100,7 +3199,7 @@ static ex H_evalf(const ex& x1, const ex& x2)
                // ensure that the realpart of the argument is positive
                if (cln::realpart(x) < 0) {
                        x = -x;
-                       for (int i=0; i<m.nops(); i++) {
+                       for (std::size_t i = 0; i < m.nops(); i++) {
                                if (m.op(i) != 0) {
                                        m.let_op(i) = -m.op(i);
                                        res *= -1;
@@ -3358,13 +3457,6 @@ namespace {
 
 // parameters and data for [Cra] algorithm
 const cln::cl_N lambda = cln::cl_N("319/320");
-int L1;
-int L2;
-std::vector<std::vector<cln::cl_N> > f_kj;
-std::vector<cln::cl_N> crB;
-std::vector<std::vector<cln::cl_N> > crG;
-std::vector<cln::cl_N> crX;
-
 
 void halfcyclic_convolute(const std::vector<cln::cl_N>& a, const std::vector<cln::cl_N>& b, std::vector<cln::cl_N>& c)
 {
@@ -3379,44 +3471,39 @@ void halfcyclic_convolute(const std::vector<cln::cl_N>& a, const std::vector<cln
 
 
 // [Cra] section 4
-void initcX(const std::vector<int>& s)
+static void initcX(std::vector<cln::cl_N>& crX,
+                  const std::vector<int>& s,
+                  const int L2)
 {
-       const int k = s.size();
-
-       crX.clear();
-       crG.clear();
-       crB.clear();
-
-       for (int i=0; i<=L2; i++) {
-               crB.push_back(bernoulli(i).to_cl_N() / cln::factorial(i));
-       }
+       std::vector<cln::cl_N> crB(L2 + 1);
+       for (int i=0; i<=L2; i++)
+               crB[i] = bernoulli(i).to_cl_N() / cln::factorial(i);
 
        int Sm = 0;
        int Smp1 = 0;
-       for (int m=0; m<k-1; m++) {
-               std::vector<cln::cl_N> crGbuf;
-               Sm = Sm + s[m];
+       std::vector<std::vector<cln::cl_N> > crG(s.size() - 1, std::vector<cln::cl_N>(L2 + 1));
+       for (int m=0; m < (int)s.size() - 1; m++) {
+               Sm += s[m];
                Smp1 = Sm + s[m+1];
-               for (int i=0; i<=L2; i++) {
-                       crGbuf.push_back(cln::factorial(i + Sm - m - 2) / cln::factorial(i + Smp1 - m - 2));
-               }
-               crG.push_back(crGbuf);
+               for (int i = 0; i <= L2; i++)
+                       crG[m][i] = cln::factorial(i + Sm - m - 2) / cln::factorial(i + Smp1 - m - 2);
        }
 
        crX = crB;
 
-       for (int m=0; m<k-1; m++) {
-               std::vector<cln::cl_N> Xbuf;
-               for (int i=0; i<=L2; i++) {
-                       Xbuf.push_back(crX[i] * crG[m][i]);
-               }
+       for (std::size_t m = 0; m < s.size() - 1; m++) {
+               std::vector<cln::cl_N> Xbuf(L2 + 1);
+               for (int i = 0; i <= L2; i++)
+                       Xbuf[i] = crX[i] * crG[m][i];
+
                halfcyclic_convolute(Xbuf, crB, crX);
        }
 }
 
 
 // [Cra] section 4
-cln::cl_N crandall_Y_loop(const cln::cl_N& Sqk)
+static cln::cl_N crandall_Y_loop(const cln::cl_N& Sqk,
+                                const std::vector<cln::cl_N>& crX)
 {
        cln::cl_F one = cln::cl_float(1, cln::float_format(Digits));
        cln::cl_N factor = cln::expt(lambda, Sqk);
@@ -3434,11 +3521,9 @@ cln::cl_N crandall_Y_loop(const cln::cl_N& Sqk)
 
 
 // [Cra] section 4
-void calc_f(int maxr)
+static void calc_f(std::vector<std::vector<cln::cl_N> >& f_kj,
+                  const int maxr, const int L1)
 {
-       f_kj.clear();
-       f_kj.resize(L1);
-       
        cln::cl_N t0, t1, t2, t3, t4;
        int i, j, k;
        std::vector<std::vector<cln::cl_N> >::iterator it = f_kj.begin();
@@ -3464,7 +3549,8 @@ void calc_f(int maxr)
 
 
 // [Cra] (3.1)
-cln::cl_N crandall_Z(const std::vector<int>& s)
+static cln::cl_N crandall_Z(const std::vector<int>& s,
+                           const std::vector<std::vector<cln::cl_N> >& f_kj)
 {
        const int j = s.size();
 
@@ -3505,6 +3591,8 @@ cln::cl_N zeta_do_sum_Crandall(const std::vector<int>& s)
        std::vector<int> r = s;
        const int j = r.size();
 
+       std::size_t L1;
+
        // decide on maximal size of f_kj for crandall_Z
        if (Digits < 50) {
                L1 = 150;
@@ -3512,6 +3600,7 @@ cln::cl_N zeta_do_sum_Crandall(const std::vector<int>& s)
                L1 = Digits * 3 + j*2;
        }
 
+       std::size_t L2;
        // decide on maximal size of crX for crandall_Y
        if (Digits < 38) {
                L2 = 63;
@@ -3538,7 +3627,8 @@ cln::cl_N zeta_do_sum_Crandall(const std::vector<int>& s)
                }
        }
 
-       calc_f(maxr);
+       std::vector<std::vector<cln::cl_N> > f_kj(L1);
+       calc_f(f_kj, maxr, L1);
 
        const cln::cl_N r0factorial = cln::factorial(r[0]-1);
 
@@ -3552,12 +3642,13 @@ cln::cl_N zeta_do_sum_Crandall(const std::vector<int>& s)
                Srun -= skp1buf;
                r.pop_back();
 
-               initcX(r);
+               std::vector<cln::cl_N> crX;
+               initcX(crX, r, L2);
                
                for (int q=0; q<skp1buf; q++) {
                        
-                       cln::cl_N pp1 = crandall_Y_loop(Srun+q-k);
-                       cln::cl_N pp2 = crandall_Z(rz);
+                       cln::cl_N pp1 = crandall_Y_loop(Srun+q-k, crX);
+                       cln::cl_N pp2 = crandall_Z(rz, f_kj);
 
                        rz.front()--;
                        
@@ -3571,9 +3662,11 @@ cln::cl_N zeta_do_sum_Crandall(const std::vector<int>& s)
        }
        rz.insert(rz.begin(), r.back());
 
-       initcX(rz);
+       std::vector<cln::cl_N> crX;
+       initcX(crX, rz, L2);
 
-       res = (res + crandall_Y_loop(S-j)) / r0factorial + crandall_Z(rz);
+       res = (res + crandall_Y_loop(S-j, crX)) / r0factorial
+               + crandall_Z(rz, f_kj);
 
        return res;
 }
@@ -3615,7 +3708,7 @@ cln::cl_N zeta_do_Hoelder_convolution(const std::vector<int>& m_, const std::vec
        s_p[0] = s_p[0] * cln::cl_N("1/2");
        // convert notations
        int sig = 1;
-       for (int i=0; i<s_.size(); i++) {
+       for (std::size_t i = 0; i < s_.size(); i++) {
                if (s_[i] < 0) {
                        sig = -sig;
                        s_p[i] = -s_p[i];