]> www.ginac.de Git - ginac.git/blobdiff - ginac/indexed.cpp
Bug in expand_dummy_sum is fixed.
[ginac.git] / ginac / indexed.cpp
index 29dd86ae5e001f7c8903ce9861c702d95f90d9ec..bd41f44b0b38a271d243564c945d674bea9acaa3 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's indexed expressions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2004 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2006 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
@@ -17,7 +17,7 @@
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #include <iostream>
 #include "operators.h"
 #include "lst.h"
 #include "archive.h"
+#include "symbol.h"
 #include "utils.h"
 #include "integral.h"
+#include "matrix.h"
+#include "inifcns.h"
 
 namespace GiNaC {
 
@@ -51,7 +54,7 @@ GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(indexed, exprseq,
 
 indexed::indexed() : symtree(not_symmetric())
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
 }
 
 //////////
@@ -60,79 +63,79 @@ indexed::indexed() : symtree(not_symmetric())
 
 indexed::indexed(const ex & b) : inherited(b), symtree(not_symmetric())
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const ex & b, const ex & i1) : inherited(b, i1), symtree(not_symmetric())
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const ex & b, const ex & i1, const ex & i2) : inherited(b, i1, i2), symtree(not_symmetric())
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const ex & b, const ex & i1, const ex & i2, const ex & i3) : inherited(b, i1, i2, i3), symtree(not_symmetric())
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const ex & b, const ex & i1, const ex & i2, const ex & i3, const ex & i4) : inherited(b, i1, i2, i3, i4), symtree(not_symmetric())
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const ex & b, const symmetry & symm, const ex & i1, const ex & i2) : inherited(b, i1, i2), symtree(symm)
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const ex & b, const symmetry & symm, const ex & i1, const ex & i2, const ex & i3) : inherited(b, i1, i2, i3), symtree(symm)
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const ex & b, const symmetry & symm, const ex & i1, const ex & i2, const ex & i3, const ex & i4) : inherited(b, i1, i2, i3, i4), symtree(symm)
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const ex & b, const exvector & v) : inherited(b), symtree(not_symmetric())
 {
        seq.insert(seq.end(), v.begin(), v.end());
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const ex & b, const symmetry & symm, const exvector & v) : inherited(b), symtree(symm)
 {
        seq.insert(seq.end(), v.begin(), v.end());
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
        validate();
 }
 
 indexed::indexed(const symmetry & symm, const exprseq & es) : inherited(es), symtree(symm)
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
 }
 
 indexed::indexed(const symmetry & symm, const exvector & v, bool discardable) : inherited(v, discardable), symtree(symm)
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
 }
 
 indexed::indexed(const symmetry & symm, std::auto_ptr<exvector> vp) : inherited(vp), symtree(symm)
 {
-       tinfo_key = TINFO_indexed;
+       tinfo_key = &indexed::tinfo_static;
 }
 
 //////////
@@ -295,6 +298,9 @@ ex indexed::eval(int level) const
                return f * thiscontainer(v);
        }
 
+       if(this->tinfo()==&indexed::tinfo_static && seq.size()==1)
+               return base;
+
        // Canonicalize indices according to the symmetry properties
        if (seq.size() > 2) {
                exvector v = seq;
@@ -312,6 +318,20 @@ ex indexed::eval(int level) const
        return ex_to<basic>(base).eval_indexed(*this);
 }
 
+ex indexed::real_part() const
+{
+       if(op(0).info(info_flags::real))
+               return *this;
+       return real_part_function(*this).hold();
+}
+
+ex indexed::imag_part() const
+{
+       if(op(0).info(info_flags::real))
+               return 0;
+       return imag_part_function(*this).hold();
+}
+
 ex indexed::thiscontainer(const exvector & v) const
 {
        return indexed(ex_to<symmetry>(symtree), v);
@@ -322,6 +342,14 @@ ex indexed::thiscontainer(std::auto_ptr<exvector> vp) const
        return indexed(ex_to<symmetry>(symtree), vp);
 }
 
+unsigned indexed::return_type() const
+{
+       if(is_a<matrix>(op(0)))
+               return return_types::commutative;
+       else
+               return op(0).return_type();
+}
+
 ex indexed::expand(unsigned options) const
 {
        GINAC_ASSERT(seq.size() > 0);
@@ -507,22 +535,6 @@ struct is_summation_idx : public std::unary_function<ex, bool> {
        }
 };
 
-exvector power::get_free_indices() const
-{
-       // Get free indices of basis
-       exvector basis_indices = basis.get_free_indices();
-
-       if (exponent.info(info_flags::even)) {
-               // If the exponent is an even number, then any "free" index that
-               // forms a dummy pair with itself is actually a summation index
-               exvector really_free;
-               std::remove_copy_if(basis_indices.begin(), basis_indices.end(),
-                                   std::back_inserter(really_free), is_summation_idx());
-               return really_free;
-       } else
-               return basis_indices;
-}
-
 exvector integral::get_free_indices() const
 {
        if (a.get_free_indices().size() || b.get_free_indices().size())
@@ -530,6 +542,15 @@ exvector integral::get_free_indices() const
        return f.get_free_indices();
 }
 
+template<class T> size_t number_of_type(const exvector&v)
+{
+       size_t number = 0;
+       for(exvector::const_iterator i=v.begin(); i!=v.end(); ++i)
+               if(is_exactly_a<T>(*i))
+                       ++number;
+       return number;
+}
+
 /** Rename dummy indices in an expression.
  *
  *  @param e Expression to work on
@@ -538,10 +559,10 @@ exvector integral::get_free_indices() const
  *  @param global_dummy_indices The set of dummy indices that have appeared
  *    before and which we would like to use in "e", too. This gets updated
  *    by the function */
-static ex rename_dummy_indices(const ex & e, exvector & global_dummy_indices, exvector & local_dummy_indices)
+template<class T> static ex rename_dummy_indices(const ex & e, exvector & global_dummy_indices, exvector & local_dummy_indices)
 {
-       size_t global_size = global_dummy_indices.size(),
-              local_size = local_dummy_indices.size();
+       size_t global_size = number_of_type<T>(global_dummy_indices),
+              local_size = number_of_type<T>(local_dummy_indices);
 
        // Any local dummy indices at all?
        if (local_size == 0)
@@ -555,7 +576,7 @@ static ex rename_dummy_indices(const ex & e, exvector & global_dummy_indices, ex
                int remaining = local_size - global_size;
                exvector::const_iterator it = local_dummy_indices.begin(), itend = local_dummy_indices.end();
                while (it != itend && remaining > 0) {
-                       if (find_if(global_dummy_indices.begin(), global_dummy_indices.end(), bind2nd(op0_is_equal(), *it)) == global_dummy_indices.end()) {
+                       if (is_exactly_a<T>(*it) && find_if(global_dummy_indices.begin(), global_dummy_indices.end(), bind2nd(idx_is_equal_ignore_dim(), *it)) == global_dummy_indices.end()) {
                                global_dummy_indices.push_back(*it);
                                global_size++;
                                remaining--;
@@ -573,11 +594,13 @@ static ex rename_dummy_indices(const ex & e, exvector & global_dummy_indices, ex
        exvector local_syms, global_syms;
        local_syms.reserve(local_size);
        global_syms.reserve(local_size);
-       for (size_t i=0; i<local_size; i++)
-               local_syms.push_back(local_dummy_indices[i].op(0));
+       for (size_t i=0; local_syms.size()!=local_size; i++)
+               if(is_exactly_a<T>(local_dummy_indices[i]))
+                       local_syms.push_back(local_dummy_indices[i].op(0));
        shaker_sort(local_syms.begin(), local_syms.end(), ex_is_less(), ex_swap());
-       for (size_t i=0; i<local_size; i++) // don't use more global symbols than necessary
-               global_syms.push_back(global_dummy_indices[i].op(0));
+       for (size_t i=0; global_syms.size()!=local_size; i++) // don't use more global symbols than necessary
+               if(is_exactly_a<T>(global_dummy_indices[i]))
+                       global_syms.push_back(global_dummy_indices[i].op(0));
        shaker_sort(global_syms.begin(), global_syms.end(), ex_is_less(), ex_swap());
 
        // Remove common indices
@@ -669,16 +692,15 @@ struct ex_base_is_less : public std::binary_function<ex, ex, bool> {
        }
 };
 
-/** Simplify product of indexed expressions (commutative, noncommutative and
- *  simple squares), return list of free indices. */
-ex simplify_indexed_product(const ex & e, exvector & free_indices, exvector & dummy_indices, const scalar_products & sp)
+/* An auxiliary function used by simplify_indexed() and expand_dummy_sum() 
+ * It returns an exvector of factors from the supplied product */
+static void product_to_exvector(const ex & e, exvector & v, bool & non_commutative)
 {
        // Remember whether the product was commutative or noncommutative
        // (because we chop it into factors and need to reassemble later)
-       bool non_commutative = is_exactly_a<ncmul>(e);
+       non_commutative = is_exactly_a<ncmul>(e);
 
        // Collect factors in an exvector, store squares twice
-       exvector v;
        v.reserve(e.nops() * 2);
 
        if (is_exactly_a<power>(e)) {
@@ -691,7 +713,7 @@ ex simplify_indexed_product(const ex & e, exvector & free_indices, exvector & du
                        ex f = e.op(i);
                        if (is_exactly_a<power>(f) && f.op(1).is_equal(_ex2)) {
                                v.push_back(f.op(0));
-                   v.push_back(f.op(0));
+                               v.push_back(f.op(0));
                        } else if (is_exactly_a<ncmul>(f)) {
                                // Noncommutative factor found, split it as well
                                non_commutative = true; // everything becomes noncommutative, ncmul will sort out the commutative factors later
@@ -701,6 +723,34 @@ ex simplify_indexed_product(const ex & e, exvector & free_indices, exvector & du
                                v.push_back(f);
                }
        }
+}
+
+template<class T> ex idx_symmetrization(const ex& r,const exvector& local_dummy_indices)
+{      exvector dummy_syms;
+       dummy_syms.reserve(r.nops());
+       for (exvector::const_iterator it = local_dummy_indices.begin(); it != local_dummy_indices.end(); ++it)
+                       if(is_exactly_a<T>(*it))
+                               dummy_syms.push_back(it->op(0));
+       if(dummy_syms.size() < 2)
+               return r;
+       ex q=symmetrize(r, dummy_syms);
+       return q;
+}
+
+// Forward declaration needed in absence of friend injection, C.f. [namespace.memdef]:
+ex simplify_indexed(const ex & e, exvector & free_indices, exvector & dummy_indices, const scalar_products & sp);
+
+/** Simplify product of indexed expressions (commutative, noncommutative and
+ *  simple squares), return list of free indices. */
+ex simplify_indexed_product(const ex & e, exvector & free_indices, exvector & dummy_indices, const scalar_products & sp)
+{
+       // Collect factors in an exvector
+       exvector v;
+
+       // Remember whether the product was commutative or noncommutative
+       // (because we chop it into factors and need to reassemble later)
+       bool non_commutative;
+       product_to_exvector(e, v, non_commutative);
 
        // Perform contractions
        bool something_changed = false;
@@ -742,20 +792,12 @@ try_again:
 
                        // At least one dummy index, is it a defined scalar product?
                        bool contracted = false;
-                       if (free.empty()) {
-
-                               // Find minimal dimension of all indices of both factors
-                               exvector::const_iterator dit = ex_to<indexed>(*it1).seq.begin() + 1, ditend = ex_to<indexed>(*it1).seq.end();
-                               ex dim = ex_to<idx>(*dit).get_dim();
-                               ++dit;
-                               for (; dit != ditend; ++dit) {
-                                       dim = minimal_dim(dim, ex_to<idx>(*dit).get_dim());
-                               }
-                               dit = ex_to<indexed>(*it2).seq.begin() + 1;
-                               ditend = ex_to<indexed>(*it2).seq.end();
-                               for (; dit != ditend; ++dit) {
-                                       dim = minimal_dim(dim, ex_to<idx>(*dit).get_dim());
-                               }
+                       if (free.empty() && it1->nops()==2 && it2->nops()==2) {
+
+                               ex dim = minimal_dim(
+                                       ex_to<idx>(it1->op(1)).get_dim(),
+                                       ex_to<idx>(it2->op(1)).get_dim()
+                               );
 
                                // User-defined scalar product?
                                if (sp.is_defined(*it1, *it2, dim)) {
@@ -850,19 +892,26 @@ contraction_done:
        // The result should be symmetric with respect to exchange of dummy
        // indices, so if the symmetrization vanishes, the whole expression is
        // zero. This detects things like eps.i.j.k * p.j * p.k = 0.
-       if (local_dummy_indices.size() >= 2) {
-               exvector dummy_syms;
-               dummy_syms.reserve(local_dummy_indices.size());
-               for (exvector::const_iterator it = local_dummy_indices.begin(); it != local_dummy_indices.end(); ++it)
-                       dummy_syms.push_back(it->op(0));
-               if (symmetrize(r, dummy_syms).is_zero()) {
-                       free_indices.clear();
-                       return _ex0;
-               }
+       ex q = idx_symmetrization<idx>(r, local_dummy_indices);
+       if (q.is_zero()) {
+               free_indices.clear();
+               return _ex0;
+       }
+       q = idx_symmetrization<varidx>(q, local_dummy_indices);
+       if (q.is_zero()) {
+               free_indices.clear();
+               return _ex0;
+       }
+       q = idx_symmetrization<spinidx>(q, local_dummy_indices);
+       if (q.is_zero()) {
+               free_indices.clear();
+               return _ex0;
        }
 
        // Dummy index renaming
-       r = rename_dummy_indices(r, dummy_indices, local_dummy_indices);
+       r = rename_dummy_indices<idx>(r, dummy_indices, local_dummy_indices);
+       r = rename_dummy_indices<varidx>(r, dummy_indices, local_dummy_indices);
+       r = rename_dummy_indices<spinidx>(r, dummy_indices, local_dummy_indices);
 
        // Product of indexed object with a scalar?
        if (is_exactly_a<mul>(r) && r.nops() == 2
@@ -929,6 +978,17 @@ public:
        }
 };
 
+bool hasindex(const ex &x, const ex &sym)
+{      
+       if(is_a<idx>(x) && x.op(0)==sym)
+               return true;
+       else
+               for(size_t i=0; i<x.nops(); ++i)
+                       if(hasindex(x.op(i), sym))
+                               return true;
+       return false;
+}
+
 /** Simplify indexed expression, return list of free indices. */
 ex simplify_indexed(const ex & e, exvector & free_indices, exvector & dummy_indices, const scalar_products & sp)
 {
@@ -957,7 +1017,10 @@ ex simplify_indexed(const ex & e, exvector & free_indices, exvector & dummy_indi
                }
 
                // Rename the dummy indices
-               return rename_dummy_indices(e_expanded, dummy_indices, local_dummy_indices);
+               e_expanded = rename_dummy_indices<idx>(e_expanded, dummy_indices, local_dummy_indices);
+               e_expanded = rename_dummy_indices<varidx>(e_expanded, dummy_indices, local_dummy_indices);
+               e_expanded = rename_dummy_indices<spinidx>(e_expanded, dummy_indices, local_dummy_indices);
+               return e_expanded;
        }
 
        // Simplification of sum = sum of simplifications, check consistency of
@@ -1001,18 +1064,19 @@ ex simplify_indexed(const ex & e, exvector & free_indices, exvector & dummy_indi
                if (num_terms_orig < 2 || dummy_indices.size() < 2)
                        return sum;
 
-               // Yes, construct vector of all dummy index symbols
-               exvector dummy_syms;
-               dummy_syms.reserve(dummy_indices.size());
-               for (exvector::const_iterator it = dummy_indices.begin(); it != dummy_indices.end(); ++it)
-                       dummy_syms.push_back(it->op(0));
-
                // Chop the sum into terms and symmetrize each one over the dummy
                // indices
                std::vector<terminfo> terms;
                for (size_t i=0; i<sum.nops(); i++) {
                        const ex & term = sum.op(i);
-                       ex term_symm = symmetrize(term, dummy_syms);
+                       exvector dummy_indices_of_term;
+                       dummy_indices_of_term.reserve(dummy_indices.size());
+                       for(exvector::iterator i=dummy_indices.begin(); i!=dummy_indices.end(); ++i)
+                               if(hasindex(term,i->op(0)))
+                                       dummy_indices_of_term.push_back(*i);
+                       ex term_symm = idx_symmetrization<idx>(term, dummy_indices_of_term);
+                       term_symm = idx_symmetrization<varidx>(term_symm, dummy_indices_of_term);
+                       term_symm = idx_symmetrization<spinidx>(term_symm, dummy_indices_of_term);
                        if (term_symm.is_zero())
                                continue;
                        terms.push_back(terminfo(term, term_symm));
@@ -1278,4 +1342,195 @@ void scalar_products::debugprint() const
        }
 }
 
+exvector get_all_dummy_indices_safely(const ex & e)
+{
+       if (is_a<indexed>(e))
+               return ex_to<indexed>(e).get_dummy_indices();
+       else if (is_a<power>(e) && e.op(1)==2) {
+               return e.op(0).get_free_indices();
+       }       
+       else if (is_a<mul>(e) || is_a<ncmul>(e)) {
+               exvector dummies;
+               exvector free_indices;
+               for (int i=0; i<e.nops(); ++i) {
+                       exvector dummies_of_factor = get_all_dummy_indices_safely(e.op(i));
+                       dummies.insert(dummies.end(), dummies_of_factor.begin(),
+                               dummies_of_factor.end());
+                       exvector free_of_factor = e.op(i).get_free_indices();
+                       free_indices.insert(free_indices.begin(), free_of_factor.begin(),
+                               free_of_factor.end());
+               }
+               exvector free_out, dummy_out;
+               find_free_and_dummy(free_indices.begin(), free_indices.end(), free_out,
+                       dummy_out);
+               dummies.insert(dummies.end(), dummy_out.begin(), dummy_out.end());
+               return dummies;
+       }
+       else if(is_a<add>(e)) {
+               exvector result;
+               for(int i=0; i<e.nops(); ++i) {
+                       exvector dummies_of_term = get_all_dummy_indices_safely(e.op(i));
+                       sort(dummies_of_term.begin(), dummies_of_term.end());
+                       exvector new_vec;
+                       set_union(result.begin(), result.end(), dummies_of_term.begin(),
+                               dummies_of_term.end(), std::back_inserter<exvector>(new_vec),
+                               ex_is_less());
+                       result.swap(new_vec);
+               }
+               return result;
+       }
+       return exvector();
+}
+
+/** Returns all dummy indices from the exvector */
+exvector get_all_dummy_indices(const ex & e)
+{
+       exvector p;
+       bool nc;
+       product_to_exvector(e, p, nc);
+       exvector::const_iterator ip = p.begin(), ipend = p.end();
+       exvector v, v1;
+       while (ip != ipend) {
+               if (is_a<indexed>(*ip)) {
+                       v1 = ex_to<indexed>(*ip).get_dummy_indices();
+                       v.insert(v.end(), v1.begin(), v1.end());
+                       exvector::const_iterator ip1 = ip+1;
+                       while (ip1 != ipend) {
+                               if (is_a<indexed>(*ip1)) {
+                                       v1 = ex_to<indexed>(*ip).get_dummy_indices(ex_to<indexed>(*ip1));
+                                       v.insert(v.end(), v1.begin(), v1.end());
+                               }
+                               ++ip1;
+                       }
+               }
+               ++ip;
+       }
+       return v;
+}
+
+lst rename_dummy_indices_uniquely(const exvector & va, const exvector & vb)
+{
+       exvector common_indices;
+       set_intersection(va.begin(), va.end(), vb.begin(), vb.end(), std::back_insert_iterator<exvector>(common_indices), ex_is_less());
+       if (common_indices.empty()) {
+               return lst(lst(), lst());
+       } else {
+               exvector new_indices, old_indices;
+               old_indices.reserve(2*common_indices.size());
+               new_indices.reserve(2*common_indices.size());
+               exvector::const_iterator ip = common_indices.begin(), ipend = common_indices.end();
+               while (ip != ipend) {
+                       ex newsym=(new symbol)->setflag(status_flags::dynallocated);
+                       ex newidx;
+                       if(is_exactly_a<spinidx>(*ip))
+                               newidx = (new spinidx(newsym, ex_to<spinidx>(*ip).get_dim(),
+                                               ex_to<spinidx>(*ip).is_covariant(),
+                                               ex_to<spinidx>(*ip).is_dotted()))
+                                       -> setflag(status_flags::dynallocated);
+                       else if (is_exactly_a<varidx>(*ip))
+                               newidx = (new varidx(newsym, ex_to<varidx>(*ip).get_dim(),
+                                               ex_to<varidx>(*ip).is_covariant()))
+                                       -> setflag(status_flags::dynallocated);
+                       else
+                               newidx = (new idx(newsym, ex_to<idx>(*ip).get_dim()))
+                                       -> setflag(status_flags::dynallocated);
+                       old_indices.push_back(*ip);
+                       new_indices.push_back(newidx);
+                       if(is_a<varidx>(*ip)) {
+                               old_indices.push_back(ex_to<varidx>(*ip).toggle_variance());
+                               new_indices.push_back(ex_to<varidx>(newidx).toggle_variance());
+                       }
+                       ++ip;
+               }
+               return lst(lst(old_indices.begin(), old_indices.end()), lst(new_indices.begin(), new_indices.end()));
+       }
+}
+
+ex rename_dummy_indices_uniquely(const exvector & va, const exvector & vb, const ex & b)
+{
+       lst indices_subs = rename_dummy_indices_uniquely(va, vb);
+       return (indices_subs.op(0).nops()>0 ? b.subs(ex_to<lst>(indices_subs.op(0)), ex_to<lst>(indices_subs.op(1)), subs_options::no_pattern|subs_options::no_index_renaming) : b);
+}
+
+ex rename_dummy_indices_uniquely(const ex & a, const ex & b)
+{
+       exvector va = get_all_dummy_indices_safely(a);
+       if (va.size() > 0) {
+               exvector vb = get_all_dummy_indices_safely(b);
+               if (vb.size() > 0) {
+                       sort(va.begin(), va.end(), ex_is_less());
+                       sort(vb.begin(), vb.end(), ex_is_less());
+                       lst indices_subs = rename_dummy_indices_uniquely(va, vb);
+                       if (indices_subs.op(0).nops() > 0)
+                               return b.subs(ex_to<lst>(indices_subs.op(0)), ex_to<lst>(indices_subs.op(1)), subs_options::no_pattern|subs_options::no_index_renaming);
+               }
+       }
+       return b;
+}
+
+ex rename_dummy_indices_uniquely(exvector & va, const ex & b, bool modify_va)
+{
+       if (va.size() > 0) {
+               exvector vb = get_all_dummy_indices_safely(b);
+               if (vb.size() > 0) {
+                       sort(vb.begin(), vb.end(), ex_is_less());
+                       lst indices_subs = rename_dummy_indices_uniquely(va, vb);
+                       if (indices_subs.op(0).nops() > 0) {
+                               if (modify_va) {
+                                       for (lst::const_iterator i = ex_to<lst>(indices_subs.op(1)).begin(); i != ex_to<lst>(indices_subs.op(1)).end(); ++i)
+                                               va.push_back(*i);
+                                       exvector uncommon_indices;
+                                       set_difference(vb.begin(), vb.end(), indices_subs.op(0).begin(), indices_subs.op(0).end(), std::back_insert_iterator<exvector>(uncommon_indices), ex_is_less());
+                                       exvector::const_iterator ip = uncommon_indices.begin(), ipend = uncommon_indices.end();
+                                       while (ip != ipend) {
+                                               va.push_back(*ip);
+                                               ++ip;
+                                       }
+                                       sort(va.begin(), va.end(), ex_is_less());
+                               }
+                               return b.subs(ex_to<lst>(indices_subs.op(0)), ex_to<lst>(indices_subs.op(1)), subs_options::no_pattern|subs_options::no_index_renaming);
+                       }
+               }
+       }
+       return b;
+}
+
+ex expand_dummy_sum(const ex & e, bool subs_idx)
+{
+       ex e_expanded = e.expand();
+       pointer_to_map_function_1arg<bool> fcn(expand_dummy_sum, subs_idx);
+       if (is_a<add>(e_expanded) || is_a<lst>(e_expanded) || is_a<matrix>(e_expanded)) {
+               return e_expanded.map(fcn);
+       } else if (is_a<ncmul>(e_expanded) || is_a<mul>(e_expanded) || is_a<power>(e_expanded) || is_a<indexed>(e_expanded)) {
+               exvector v;
+               if (is_a<indexed>(e_expanded))
+                       v = ex_to<indexed>(e_expanded).get_dummy_indices();
+               else
+                       v = get_all_dummy_indices(e_expanded);
+               ex result = e_expanded;
+               for(exvector::const_iterator it=v.begin(); it!=v.end(); ++it) {
+                       ex nu = *it;
+                       if (ex_to<idx>(nu).get_dim().info(info_flags::nonnegint)) {
+                               int idim = ex_to<numeric>(ex_to<idx>(nu).get_dim()).to_int();
+                               ex en = 0;
+                               for (int i=0; i < idim; i++) {
+                                       if (subs_idx && is_a<varidx>(nu)) {
+                                               ex other = ex_to<varidx>(nu).toggle_variance();
+                                               en += result.subs(lst(
+                                                       nu == idx(i, idim),
+                                                       other == idx(i, idim)
+                                               ));
+                                       } else {
+                                               en += result.subs( nu.op(0) == i );
+                                       }
+                               }
+                               result = en;
+                       }
+               }
+               return result;
+       } else {
+               return e;
+       }
+}
+
 } // namespace GiNaC