]> www.ginac.de Git - ginac.git/blobdiff - ginac/expairseq.cpp
Remove unfinished code for hash table-based expairseq.
[ginac.git] / ginac / expairseq.cpp
index 5652d89c30b4b3772e10af0089fca66e77a6ce8c..18aba0dbdcb8900587ce5cc746efebf5b064db80 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of sequences of expression pairs. */
 
 /*
- *  GiNaC Copyright (C) 1999-2006 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2015 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 <iostream>
-#include <algorithm>
-#include <string>
-#include <stdexcept>
-
 #include "expairseq.h"
 #include "lst.h"
 #include "add.h"
 #include "archive.h"
 #include "operators.h"
 #include "utils.h"
+#include "hash_seed.h"
 #include "indexed.h"
 
-#if EXPAIRSEQ_USE_HASHTAB
-#include <cmath>
-#endif // EXPAIRSEQ_USE_HASHTAB
+#include <algorithm>
+#include <iostream>
+#include <iterator>
+#include <stdexcept>
+#include <string>
 
 namespace GiNaC {
 
@@ -68,71 +66,41 @@ public:
 
 // public
 
-expairseq::expairseq() : inherited(&expairseq::tinfo_static)
-#if EXPAIRSEQ_USE_HASHTAB
-                                                   , hashtabsize(0)
-#endif // EXPAIRSEQ_USE_HASHTAB
+expairseq::expairseq() 
 {}
 
 // protected
 
-#if 0
-/** For use by copy ctor and assignment operator. */
-void expairseq::copy(const expairseq &other)
-{
-       seq = other.seq;
-       overall_coeff = other.overall_coeff;
-#if EXPAIRSEQ_USE_HASHTAB
-       // copy hashtab
-       hashtabsize = other.hashtabsize;
-       if (hashtabsize!=0) {
-               hashmask = other.hashmask;
-               hashtab.resize(hashtabsize);
-               epvector::const_iterator osb = other.seq.begin();
-               for (unsigned i=0; i<hashtabsize; ++i) {
-                       hashtab[i].clear();
-                       for (epplist::const_iterator cit=other.hashtab[i].begin();
-                            cit!=other.hashtab[i].end(); ++cit) {
-                               hashtab[i].push_back(seq.begin()+((*cit)-osb));
-                       }
-               }
-       } else {
-               hashtab.clear();
-       }
-#endif // EXPAIRSEQ_USE_HASHTAB
-}
-#endif
-
 //////////
 // other constructors
 //////////
 
-expairseq::expairseq(const ex &lh, const ex &rh) : inherited(&expairseq::tinfo_static)
+expairseq::expairseq(const ex &lh, const ex &rh)
 {
        construct_from_2_ex(lh,rh);
        GINAC_ASSERT(is_canonical());
 }
 
-expairseq::expairseq(const exvector &v) : inherited(&expairseq::tinfo_static)
+expairseq::expairseq(const exvector &v)
 {
        construct_from_exvector(v);
        GINAC_ASSERT(is_canonical());
 }
 
-expairseq::expairseq(const epvector &v, const ex &oc)
-  : inherited(&expairseq::tinfo_static), overall_coeff(oc)
+expairseq::expairseq(const epvector &v, const ex &oc, bool do_index_renaming)
+  :  overall_coeff(oc)
 {
        GINAC_ASSERT(is_a<numeric>(oc));
-       construct_from_epvector(v);
+       construct_from_epvector(v, do_index_renaming);
        GINAC_ASSERT(is_canonical());
 }
 
-expairseq::expairseq(std::auto_ptr<epvector> vp, const ex &oc)
-  : inherited(&expairseq::tinfo_static), overall_coeff(oc)
+expairseq::expairseq(std::auto_ptr<epvector> vp, const ex &oc, bool do_index_renaming)
+  :  overall_coeff(oc)
 {
        GINAC_ASSERT(vp.get()!=0);
        GINAC_ASSERT(is_a<numeric>(oc));
-       construct_from_epvector(*vp);
+       construct_from_epvector(*vp, do_index_renaming);
        GINAC_ASSERT(is_canonical());
 }
 
@@ -140,18 +108,20 @@ expairseq::expairseq(std::auto_ptr<epvector> vp, const ex &oc)
 // archiving
 //////////
 
-expairseq::expairseq(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
-#if EXPAIRSEQ_USE_HASHTAB
-       , hashtabsize(0)
-#endif
+void expairseq::read_archive(const archive_node &n, lst &sym_lst) 
 {
-       for (unsigned int i=0; true; i++) {
+       inherited::read_archive(n, sym_lst);
+       archive_node::archive_node_cit first = n.find_first("rest");
+       archive_node::archive_node_cit last = n.find_last("coeff");
+       ++last;
+       seq.reserve((last-first)/2);
+
+       for (archive_node::archive_node_cit loc = first; loc < last;) {
                ex rest;
                ex coeff;
-               if (n.find_ex("rest", rest, sym_lst, i) && n.find_ex("coeff", coeff, sym_lst, i))
-                       seq.push_back(expair(rest, coeff));
-               else
-                       break;
+               n.find_ex_by_loc(loc++, rest, sym_lst);
+               n.find_ex_by_loc(loc++, coeff, sym_lst);
+               seq.push_back(expair(rest, coeff));
        }
 
        n.find_ex("overall_coeff", overall_coeff, sym_lst);
@@ -172,7 +142,6 @@ void expairseq::archive(archive_node &n) const
        n.add_ex("overall_coeff", overall_coeff);
 }
 
-DEFAULT_UNARCHIVE(expairseq)
 
 //////////
 // functions overriding virtual functions from base classes
@@ -206,63 +175,30 @@ void expairseq::do_print_tree(const print_tree & c, unsigned level) const
                overall_coeff.print(c, level + c.delta_indent);
        }
        c.s << std::string(level + c.delta_indent,' ') << "=====" << std::endl;
-#if EXPAIRSEQ_USE_HASHTAB
-       c.s << std::string(level + c.delta_indent,' ')
-           << "hashtab size " << hashtabsize << std::endl;
-       if (hashtabsize == 0) return;
-#define MAXCOUNT 5
-       unsigned count[MAXCOUNT+1];
-       for (int i=0; i<MAXCOUNT+1; ++i)
-               count[i] = 0;
-       unsigned this_bin_fill;
-       unsigned cum_fill_sq = 0;
-       unsigned cum_fill = 0;
-       for (unsigned i=0; i<hashtabsize; ++i) {
-               this_bin_fill = 0;
-               if (hashtab[i].size() > 0) {
-                       c.s << std::string(level + c.delta_indent, ' ')
-                           << "bin " << i << " with entries ";
-                       for (epplist::const_iterator it=hashtab[i].begin();
-                            it!=hashtab[i].end(); ++it) {
-                               c.s << *it-seq.begin() << " ";
-                               ++this_bin_fill;
-                       }
-                       c.s << std::endl;
-                       cum_fill += this_bin_fill;
-                       cum_fill_sq += this_bin_fill*this_bin_fill;
-               }
-               if (this_bin_fill<MAXCOUNT)
-                       ++count[this_bin_fill];
-               else
-                       ++count[MAXCOUNT];
-       }
-       unsigned fact = 1;
-       double cum_prob = 0;
-       double lambda = (1.0*seq.size()) / hashtabsize;
-       for (int k=0; k<MAXCOUNT; ++k) {
-               if (k>0)
-                       fact *= k;
-               double prob = std::pow(lambda,k)/fact * std::exp(-lambda);
-               cum_prob += prob;
-               c.s << std::string(level + c.delta_indent, ' ') << "bins with " << k << " entries: "
-                   << int(1000.0*count[k]/hashtabsize)/10.0 << "% (expected: "
-                   << int(prob*1000)/10.0 << ")" << std::endl;
-       }
-       c.s << std::string(level + c.delta_indent, ' ') << "bins with more entries: "
-           << int(1000.0*count[MAXCOUNT]/hashtabsize)/10.0 << "% (expected: "
-           << int((1-cum_prob)*1000)/10.0 << ")" << std::endl;
-
-       c.s << std::string(level + c.delta_indent, ' ') << "variance: "
-           << 1.0/hashtabsize*cum_fill_sq-(1.0/hashtabsize*cum_fill)*(1.0/hashtabsize*cum_fill)
-           << std::endl;
-       c.s << std::string(level + c.delta_indent, ' ') << "average fill: "
-           << (1.0*cum_fill)/hashtabsize
-           << " (should be equal to " << (1.0*seq.size())/hashtabsize << ")" << std::endl;
-#endif // EXPAIRSEQ_USE_HASHTAB
 }
 
 bool expairseq::info(unsigned inf) const
 {
+       switch(inf) {
+               case info_flags::expanded:
+                       return (flags & status_flags::expanded);
+               case info_flags::has_indices: {
+                       if (flags & status_flags::has_indices)
+                               return true;
+                       else if (flags & status_flags::has_no_indices)
+                               return false;
+                       for (epvector::const_iterator i = seq.begin(); i != seq.end(); ++i) {
+                               if (i->rest.info(info_flags::has_indices)) {
+                                       this->setflag(status_flags::has_indices);
+                                       this->clearflag(status_flags::has_no_indices);
+                                       return true;
+                               }
+                       }
+                       this->clearflag(status_flags::has_indices);
+                       this->setflag(status_flags::has_no_indices);
+                       return false;
+               }
+       }
        return inherited::info(inf);
 }
 
@@ -285,7 +221,7 @@ ex expairseq::op(size_t i) const
 ex expairseq::map(map_function &f) const
 {
        std::auto_ptr<epvector> v(new epvector);
-       v->reserve(seq.size());
+       v->reserve(seq.size()+1);
 
        epvector::const_iterator cit = seq.begin(), last = seq.end();
        while (cit != last) {
@@ -294,9 +230,16 @@ ex expairseq::map(map_function &f) const
        }
 
        if (overall_coeff.is_equal(default_overall_coeff()))
-               return thisexpairseq(v, default_overall_coeff());
-       else
-               return thisexpairseq(v, f(overall_coeff));
+               return thisexpairseq(v, default_overall_coeff(), true);
+       else {
+               ex newcoeff = f(overall_coeff);
+               if(is_a<numeric>(newcoeff))
+                       return thisexpairseq(v, newcoeff, true);
+               else {
+                       v->push_back(split_ex_to_pair(newcoeff));
+                       return thisexpairseq(v, default_overall_coeff(), true);
+               }
+       }
 }
 
 /** Perform coefficient-wise automatic term rewriting rules in this class. */
@@ -342,29 +285,16 @@ ex expairseq::conjugate() const
                return *this;
        }
        ex result = thisexpairseq(newepv ? *newepv : seq, x);
-       if (newepv) {
-               delete newepv;
-       }
+       delete newepv;
        return result;
 }
 
-bool expairseq::is_polynomial(const ex & var) const
-{
-       if (!is_exactly_a<add>(*this) && !is_exactly_a<mul>(*this))
-               return basic::is_polynomial(var);
-       for (epvector::const_iterator i=seq.begin(); i!=seq.end(); ++i) {
-               if (!(i->rest).is_polynomial(var))
-                       return false;
-       }
-       return true;
-}
-
-bool expairseq::match(const ex & pattern, lst & repl_lst) const
+bool expairseq::match(const ex & pattern, exmap & repl_lst) const
 {
        // This differs from basic::match() because we want "a+b+c+d" to
        // match "d+*+b" with "*" being "a+c", and we want to honor commutativity
 
-       if (this->tinfo() == ex_to<basic>(pattern).tinfo()) {
+       if (typeid(*this) == typeid(ex_to<basic>(pattern))) {
 
                // Check whether global wildcard (one that matches the "rest of the
                // expression", like "*" above) is present
@@ -378,6 +308,12 @@ bool expairseq::match(const ex & pattern, lst & repl_lst) const
                        }
                }
 
+               // Even if the expression does not match the pattern, some of
+               // its subexpressions could match it. For example, x^5*y^(-1)
+               // does not match the pattern $0^5, but its subexpression x^5
+               // does. So, save repl_lst in order to not add bogus entries.
+               exmap tmp_repl = repl_lst;
+
                // Unfortunately, this is an O(N^2) operation because we can't
                // sort the pattern in a useful way...
 
@@ -395,7 +331,7 @@ bool expairseq::match(const ex & pattern, lst & repl_lst) const
                                continue;
                        exvector::iterator it = ops.begin(), itend = ops.end();
                        while (it != itend) {
-                               if (it->match(p, repl_lst)) {
+                               if (it->match(p, tmp_repl)) {
                                        ops.erase(it);
                                        goto found;
                                }
@@ -416,18 +352,28 @@ found:            ;
                        for (size_t i=0; i<num; i++)
                                vp->push_back(split_ex_to_pair(ops[i]));
                        ex rest = thisexpairseq(vp, default_overall_coeff());
-                       for (lst::const_iterator it = repl_lst.begin(); it != repl_lst.end(); ++it) {
-                               if (it->op(0).is_equal(global_wildcard))
-                                       return rest.is_equal(it->op(1));
+                       for (exmap::const_iterator it = tmp_repl.begin(); it != tmp_repl.end(); ++it) {
+                               if (it->first.is_equal(global_wildcard)) {
+                                       if (rest.is_equal(it->second)) {
+                                               repl_lst = tmp_repl;
+                                               return true;
+                                       }
+                                       return false;
+                               }
                        }
-                       repl_lst.append(global_wildcard == rest);
+                       repl_lst = tmp_repl;
+                       repl_lst[global_wildcard] = rest;
                        return true;
 
                } else {
 
                        // No global wildcard, then the match fails if there are any
                        // unmatched terms left
-                       return ops.empty();
+                       if (ops.empty()) {
+                               repl_lst = tmp_repl;
+                               return true;
+                       }
+                       return false;
                }
        }
        return inherited::match(pattern, repl_lst);
@@ -437,7 +383,7 @@ ex expairseq::subs(const exmap & m, unsigned options) const
 {
        std::auto_ptr<epvector> vp = subschildren(m, options);
        if (vp.get())
-               return ex_to<basic>(thisexpairseq(vp, overall_coeff));
+               return ex_to<basic>(thisexpairseq(vp, overall_coeff, (options & subs_options::no_index_renaming) == 0));
        else if ((options & subs_options::algebraic) && is_exactly_a<mul>(*this))
                return static_cast<const mul *>(this)->algebraic_subs_mul(m, options);
        else
@@ -462,54 +408,20 @@ int expairseq::compare_same_type(const basic &other) const
        if (cmpval!=0)
                return cmpval;
        
-#if EXPAIRSEQ_USE_HASHTAB
-       GINAC_ASSERT(hashtabsize==o.hashtabsize);
-       if (hashtabsize==0) {
-#endif // EXPAIRSEQ_USE_HASHTAB
-               epvector::const_iterator cit1 = seq.begin();
-               epvector::const_iterator cit2 = o.seq.begin();
-               epvector::const_iterator last1 = seq.end();
-               epvector::const_iterator last2 = o.seq.end();
+       epvector::const_iterator cit1 = seq.begin();
+       epvector::const_iterator cit2 = o.seq.begin();
+       epvector::const_iterator last1 = seq.end();
+       epvector::const_iterator last2 = o.seq.end();
                
-               for (; (cit1!=last1)&&(cit2!=last2); ++cit1, ++cit2) {
-                       cmpval = (*cit1).compare(*cit2);
-                       if (cmpval!=0) return cmpval;
-               }
+       for (; (cit1!=last1)&&(cit2!=last2); ++cit1, ++cit2) {
+               cmpval = (*cit1).compare(*cit2);
+               if (cmpval!=0) return cmpval;
+       }
                
-               GINAC_ASSERT(cit1==last1);
-               GINAC_ASSERT(cit2==last2);
+       GINAC_ASSERT(cit1==last1);
+       GINAC_ASSERT(cit2==last2);
                
-               return 0;
-#if EXPAIRSEQ_USE_HASHTAB
-       }
-       
-       // compare number of elements in each hashtab entry
-       for (unsigned i=0; i<hashtabsize; ++i) {
-               unsigned cursize=hashtab[i].size();
-               if (cursize != o.hashtab[i].size())
-                       return (cursize < o.hashtab[i].size()) ? -1 : 1;
-       }
-       
-       // compare individual (sorted) hashtab entries
-       for (unsigned i=0; i<hashtabsize; ++i) {
-               unsigned sz = hashtab[i].size();
-               if (sz>0) {
-                       const epplist &eppl1 = hashtab[i];
-                       const epplist &eppl2 = o.hashtab[i];
-                       epplist::const_iterator it1 = eppl1.begin();
-                       epplist::const_iterator it2 = eppl2.begin();
-                       while (it1!=eppl1.end()) {
-                               cmpval = (*(*it1)).compare(*(*it2));
-                               if (cmpval!=0)
-                                       return cmpval;
-                               ++it1;
-                               ++it2;
-                       }
-               }
-       }
-       
-       return 0; // equal
-#endif // EXPAIRSEQ_USE_HASHTAB
+       return 0;
 }
 
 bool expairseq::is_equal_same_type(const basic &other) const
@@ -524,56 +436,17 @@ bool expairseq::is_equal_same_type(const basic &other) const
        if (!overall_coeff.is_equal(o.overall_coeff))
                return false;
        
-#if EXPAIRSEQ_USE_HASHTAB
-       // compare number of elements in each hashtab entry
-       if (hashtabsize!=o.hashtabsize) {
-               std::cout << "this:" << std::endl;
-               print(print_tree(std::cout));
-               std::cout << "other:" << std::endl;
-               other.print(print_tree(std::cout));
-       }
+       epvector::const_iterator cit1 = seq.begin();
+       epvector::const_iterator cit2 = o.seq.begin();
+       epvector::const_iterator last1 = seq.end();
                
-       GINAC_ASSERT(hashtabsize==o.hashtabsize);
-       
-       if (hashtabsize==0) {
-#endif // EXPAIRSEQ_USE_HASHTAB
-               epvector::const_iterator cit1 = seq.begin();
-               epvector::const_iterator cit2 = o.seq.begin();
-               epvector::const_iterator last1 = seq.end();
-               
-               while (cit1!=last1) {
-                       if (!(*cit1).is_equal(*cit2)) return false;
-                       ++cit1;
-                       ++cit2;
-               }
-               
-               return true;
-#if EXPAIRSEQ_USE_HASHTAB
-       }
-       
-       for (unsigned i=0; i<hashtabsize; ++i) {
-               if (hashtab[i].size() != o.hashtab[i].size())
-                       return false;
+       while (cit1!=last1) {
+               if (!(*cit1).is_equal(*cit2)) return false;
+               ++cit1;
+               ++cit2;
        }
 
-       // compare individual sorted hashtab entries
-       for (unsigned i=0; i<hashtabsize; ++i) {
-               unsigned sz = hashtab[i].size();
-               if (sz>0) {
-                       const epplist &eppl1 = hashtab[i];
-                       const epplist &eppl2 = o.hashtab[i];
-                       epplist::const_iterator it1 = eppl1.begin();
-                       epplist::const_iterator it2 = eppl2.begin();
-                       while (it1!=eppl1.end()) {
-                               if (!(*(*it1)).is_equal(*(*it2))) return false;
-                               ++it1;
-                               ++it2;
-                       }
-               }
-       }
-       
        return true;
-#endif // EXPAIRSEQ_USE_HASHTAB
 }
 
 unsigned expairseq::return_type() const
@@ -583,16 +456,14 @@ unsigned expairseq::return_type() const
 
 unsigned expairseq::calchash() const
 {
-       unsigned v = golden_ratio_hash((p_int)this->tinfo());
+       unsigned v = make_hash_seed(typeid(*this));
        epvector::const_iterator i = seq.begin();
        const epvector::const_iterator end = seq.end();
        while (i != end) {
                v ^= i->rest.gethash();
-#if !EXPAIRSEQ_USE_HASHTAB
                // rotation spoils commutativity!
                v = rotate_left(v);
                v ^= i->coeff.gethash();
-#endif // !EXPAIRSEQ_USE_HASHTAB
                ++i;
        }
 
@@ -629,17 +500,17 @@ ex expairseq::expand(unsigned options) const
  *  has (at least) two possible different semantics but we want to inherit
  *  methods thus avoiding code duplication.  Sometimes a method in expairseq
  *  has to create a new one of the same semantics, which cannot be done by a
- *  ctor because the name (add, mul,...) is unknown on the expaiseq level.  In
+ *  ctor because the name (add, mul,...) is unknown on the expairseq level.  In
  *  order for this trick to work a derived class must of course override this
  *  definition. */
-ex expairseq::thisexpairseq(const epvector &v, const ex &oc) const
+ex expairseq::thisexpairseq(const epvector &v, const ex &oc, bool do_index_renaming) const
 {
-       return expairseq(v, oc);
+       return expairseq(v, oc, do_index_renaming);
 }
 
-ex expairseq::thisexpairseq(std::auto_ptr<epvector> vp, const ex &oc) const
+ex expairseq::thisexpairseq(std::auto_ptr<epvector> vp, const ex &oc, bool do_index_renaming) const
 {
-       return expairseq(vp, oc);
+       return expairseq(vp, oc, do_index_renaming);
 }
 
 void expairseq::printpair(const print_context & c, const expair & p, unsigned upper_precedence) const
@@ -709,9 +580,6 @@ ex expairseq::recombine_pair_to_ex(const expair &p) const
 
 bool expairseq::expair_needs_further_processing(epp it)
 {
-#if EXPAIRSEQ_USE_HASHTAB
-       //#  error "FIXME: expair_needs_further_processing not yet implemented for hashtabs, sorry. A.F."
-#endif // EXPAIRSEQ_USE_HASHTAB
        return false;
 }
 
@@ -753,70 +621,30 @@ void expairseq::construct_from_2_ex_via_exvector(const ex &lh, const ex &rh)
        v.push_back(lh);
        v.push_back(rh);
        construct_from_exvector(v);
-#if EXPAIRSEQ_USE_HASHTAB
-       GINAC_ASSERT((hashtabsize==0)||(hashtabsize>=minhashtabsize));
-       GINAC_ASSERT(hashtabsize==calc_hashtabsize(seq.size()));
-#endif // EXPAIRSEQ_USE_HASHTAB
 }
 
 void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
 {
-       if (ex_to<basic>(lh).tinfo()==this->tinfo()) {
-               if (ex_to<basic>(rh).tinfo()==this->tinfo()) {
-#if EXPAIRSEQ_USE_HASHTAB
-                       unsigned totalsize = ex_to<expairseq>(lh).seq.size() +
-                                            ex_to<expairseq>(rh).seq.size();
-                       if (calc_hashtabsize(totalsize)!=0) {
-                               construct_from_2_ex_via_exvector(lh,rh);
-                       } else {
-#endif // EXPAIRSEQ_USE_HASHTAB
-                               if(is_a<mul>(lh))
-                               {       
-                                       ex newrh=rename_dummy_indices_uniquely(lh, rh);
-                                       construct_from_2_expairseq(ex_to<expairseq>(lh),
-                                                                  ex_to<expairseq>(newrh));
-                               }
-                               else
-                                       construct_from_2_expairseq(ex_to<expairseq>(lh),
-                                                                  ex_to<expairseq>(rh));
-#if EXPAIRSEQ_USE_HASHTAB
+       if (typeid(ex_to<basic>(lh)) == typeid(*this)) {
+               if (typeid(ex_to<basic>(rh)) == typeid(*this)) {
+                       if (is_a<mul>(lh) && lh.info(info_flags::has_indices) && 
+                               rh.info(info_flags::has_indices)) {
+                               ex newrh=rename_dummy_indices_uniquely(lh, rh);
+                               construct_from_2_expairseq(ex_to<expairseq>(lh),
+                                                          ex_to<expairseq>(newrh));
                        }
-#endif // EXPAIRSEQ_USE_HASHTAB
+                       else
+                               construct_from_2_expairseq(ex_to<expairseq>(lh),
+                                                          ex_to<expairseq>(rh));
                        return;
                } else {
-#if EXPAIRSEQ_USE_HASHTAB
-                       unsigned totalsize = ex_to<expairseq>(lh).seq.size()+1;
-                       if (calc_hashtabsize(totalsize)!=0) {
-                               construct_from_2_ex_via_exvector(lh, rh);
-                       } else {
-#endif // EXPAIRSEQ_USE_HASHTAB
-                               construct_from_expairseq_ex(ex_to<expairseq>(lh), rh);
-#if EXPAIRSEQ_USE_HASHTAB
-                       }
-#endif // EXPAIRSEQ_USE_HASHTAB
+                       construct_from_expairseq_ex(ex_to<expairseq>(lh), rh);
                        return;
                }
-       } else if (ex_to<basic>(rh).tinfo()==this->tinfo()) {
-#if EXPAIRSEQ_USE_HASHTAB
-               unsigned totalsize=ex_to<expairseq>(rh).seq.size()+1;
-               if (calc_hashtabsize(totalsize)!=0) {
-                       construct_from_2_ex_via_exvector(lh,rh);
-               } else {
-#endif // EXPAIRSEQ_USE_HASHTAB
-                       construct_from_expairseq_ex(ex_to<expairseq>(rh),lh);
-#if EXPAIRSEQ_USE_HASHTAB
-               }
-#endif // EXPAIRSEQ_USE_HASHTAB
-               return;
-       }
-       
-#if EXPAIRSEQ_USE_HASHTAB
-       if (calc_hashtabsize(2)!=0) {
-               construct_from_2_ex_via_exvector(lh,rh);
+       } else if (typeid(ex_to<basic>(rh)) == typeid(*this)) {
+               construct_from_expairseq_ex(ex_to<expairseq>(rh),lh);
                return;
        }
-       hashtabsize = 0;
-#endif // EXPAIRSEQ_USE_HASHTAB
        
        if (is_exactly_a<numeric>(lh)) {
                if (is_exactly_a<numeric>(rh)) {
@@ -857,7 +685,7 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
 }
 
 void expairseq::construct_from_2_expairseq(const expairseq &s1,
-                                                                                  const expairseq &s2)
+                                           const expairseq &s2)
 {
        combine_overall_coeff(s1.overall_coeff);
        combine_overall_coeff(s2.overall_coeff);
@@ -912,7 +740,7 @@ void expairseq::construct_from_2_expairseq(const expairseq &s1,
 }
 
 void expairseq::construct_from_expairseq_ex(const expairseq &s,
-                                                                                       const ex &e)
+                                            const ex &e)
 {
        combine_overall_coeff(s.overall_coeff);
        if (is_exactly_a<numeric>(e)) {
@@ -977,32 +805,24 @@ void expairseq::construct_from_exvector(const exvector &v)
 {
        // simplifications: +(a,+(b,c),d) -> +(a,b,c,d) (associativity)
        //                  +(d,b,c,a) -> +(a,b,c,d) (canonicalization)
-       //                  +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric())
+       //                  +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric)
        //                  (same for (+,*) -> (*,^)
 
        make_flat(v);
-#if EXPAIRSEQ_USE_HASHTAB
-       combine_same_terms();
-#else
        canonicalize();
        combine_same_terms_sorted_seq();
-#endif // EXPAIRSEQ_USE_HASHTAB
 }
 
-void expairseq::construct_from_epvector(const epvector &v)
+void expairseq::construct_from_epvector(const epvector &v, bool do_index_renaming)
 {
        // simplifications: +(a,+(b,c),d) -> +(a,b,c,d) (associativity)
        //                  +(d,b,c,a) -> +(a,b,c,d) (canonicalization)
-       //                  +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric())
-       //                  (same for (+,*) -> (*,^)
+       //                  +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric)
+       //                  same for (+,*) -> (*,^)
 
-       make_flat(v);
-#if EXPAIRSEQ_USE_HASHTAB
-       combine_same_terms();
-#else
+       make_flat(v, do_index_renaming);
        canonicalize();
        combine_same_terms_sorted_seq();
-#endif // EXPAIRSEQ_USE_HASHTAB
 }
 
 /** Combine this expairseq with argument exvector.
@@ -1015,13 +835,17 @@ void expairseq::make_flat(const exvector &v)
        // and their cumulative number of operands
        int nexpairseqs = 0;
        int noperands = 0;
+       bool do_idx_rename = false;
        
        cit = v.begin();
        while (cit!=v.end()) {
-               if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
+               if (typeid(ex_to<basic>(*cit)) == typeid(*this)) {
                        ++nexpairseqs;
                        noperands += ex_to<expairseq>(*cit).seq.size();
                }
+               if (is_a<mul>(*this) && (!do_idx_rename) &&
+                               cit->info(info_flags::has_indices))
+                       do_idx_rename = true;
                ++cit;
        }
        
@@ -1029,35 +853,25 @@ void expairseq::make_flat(const exvector &v)
        seq.reserve(v.size()+noperands-nexpairseqs);
        
        // copy elements and split off numerical part
-       exvector dummy_indices;
+       make_flat_inserter mf(v, do_idx_rename);
        cit = v.begin();
        while (cit!=v.end()) {
-               if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
-                       const expairseq *subseqref;
-                       ex newfactor;
-                       if(is_a<mul>(*cit))
-                       {
-                               exvector dummies_of_factor = get_all_dummy_indices(*cit);
-                               sort(dummies_of_factor.begin(), dummies_of_factor.end(), ex_is_less());
-                               newfactor = rename_dummy_indices_uniquely(dummy_indices, dummies_of_factor, *cit);
-                               subseqref = &(ex_to<expairseq>(newfactor));
-                               exvector new_dummy_indices;
-                               set_union(dummy_indices.begin(), dummy_indices.end(), dummies_of_factor.begin(), dummies_of_factor.end(), std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-                               dummy_indices.swap(new_dummy_indices);
-                       }
-                       else
-                               subseqref = &ex_to<expairseq>(*cit);
-                       combine_overall_coeff(subseqref->overall_coeff);
-                       epvector::const_iterator cit_s = subseqref->seq.begin();
-                       while (cit_s!=subseqref->seq.end()) {
+               if (typeid(ex_to<basic>(*cit)) == typeid(*this)) {
+                       ex newfactor = mf.handle_factor(*cit, _ex1);
+                       const expairseq &subseqref = ex_to<expairseq>(newfactor);
+                       combine_overall_coeff(subseqref.overall_coeff);
+                       epvector::const_iterator cit_s = subseqref.seq.begin();
+                       while (cit_s!=subseqref.seq.end()) {
                                seq.push_back(*cit_s);
                                ++cit_s;
                        }
                } else {
                        if (is_exactly_a<numeric>(*cit))
                                combine_overall_coeff(*cit);
-                       else
-                               seq.push_back(split_ex_to_pair(*cit));
+                       else {
+                               ex newfactor = mf.handle_factor(*cit, _ex1);
+                               seq.push_back(split_ex_to_pair(newfactor));
+                       }
                }
                ++cit;
        }
@@ -1065,7 +879,7 @@ void expairseq::make_flat(const exvector &v)
 
 /** Combine this expairseq with argument epvector.
  *  It cares for associativity as well as for special handling of numerics. */
-void expairseq::make_flat(const epvector &v)
+void expairseq::make_flat(const epvector &v, bool do_index_renaming)
 {
        epvector::const_iterator cit;
        
@@ -1073,25 +887,32 @@ void expairseq::make_flat(const epvector &v)
        // and their cumulative number of operands
        int nexpairseqs = 0;
        int noperands = 0;
+       bool really_need_rename_inds = false;
        
        cit = v.begin();
        while (cit!=v.end()) {
-               if (ex_to<basic>(cit->rest).tinfo()==this->tinfo()) {
+               if (typeid(ex_to<basic>(cit->rest)) == typeid(*this)) {
                        ++nexpairseqs;
                        noperands += ex_to<expairseq>(cit->rest).seq.size();
                }
+               if ((!really_need_rename_inds) && is_a<mul>(*this) &&
+                               cit->rest.info(info_flags::has_indices))
+                       really_need_rename_inds = true;
                ++cit;
        }
+       do_index_renaming = do_index_renaming && really_need_rename_inds;
        
        // reserve seq and coeffseq which will hold all operands
        seq.reserve(v.size()+noperands-nexpairseqs);
+       make_flat_inserter mf(v, do_index_renaming);
        
        // copy elements and split off numerical part
        cit = v.begin();
        while (cit!=v.end()) {
-               if (ex_to<basic>(cit->rest).tinfo()==this->tinfo() &&
+               if ((typeid(ex_to<basic>(cit->rest)) == typeid(*this)) &&
                    this->can_make_flat(*cit)) {
-                       const expairseq &subseqref = ex_to<expairseq>(cit->rest);
+                       ex newrest = mf.handle_factor(cit->rest, cit->coeff);
+                       const expairseq &subseqref = ex_to<expairseq>(newrest);
                        combine_overall_coeff(ex_to<numeric>(subseqref.overall_coeff),
                                                            ex_to<numeric>(cit->coeff));
                        epvector::const_iterator cit_s = subseqref.seq.begin();
@@ -1104,9 +925,15 @@ void expairseq::make_flat(const epvector &v)
                        }
                } else {
                        if (cit->is_canonical_numeric())
-                               combine_overall_coeff(cit->rest);
-                       else
-                               seq.push_back(*cit);
+                               combine_overall_coeff(mf.handle_factor(cit->rest, _ex1));
+                       else {
+                               ex rest = cit->rest;
+                               ex newrest = mf.handle_factor(rest, cit->coeff);
+                               if (are_ex_trivially_equal(newrest, rest))
+                                       seq.push_back(*cit);
+                               else
+                                       seq.push_back(expair(newrest, cit->coeff));
+                       }
                }
                ++cit;
        }
@@ -1168,315 +995,6 @@ void expairseq::combine_same_terms_sorted_seq()
        }
 }
 
-#if EXPAIRSEQ_USE_HASHTAB
-
-unsigned expairseq::calc_hashtabsize(unsigned sz) const
-{
-       unsigned size;
-       unsigned nearest_power_of_2 = 1 << log2(sz);
-       // if (nearest_power_of_2 < maxhashtabsize/hashtabfactor) {
-       //  size = nearest_power_of_2*hashtabfactor;
-       size = nearest_power_of_2/hashtabfactor;
-       if (size<minhashtabsize)
-               return 0;
-
-       // hashtabsize must be a power of 2
-       GINAC_ASSERT((1U << log2(size))==size);
-       return size;
-}
-
-unsigned expairseq::calc_hashindex(const ex &e) const
-{
-       // calculate hashindex
-       unsigned hashindex;
-       if (is_a<numeric>(e)) {
-               hashindex = hashmask;
-       } else {
-               hashindex = e.gethash() & hashmask;
-               // last hashtab entry is reserved for numerics
-               if (hashindex==hashmask) hashindex = 0;
-       }
-       GINAC_ASSERT((hashindex<hashtabsize)||(hashtabsize==0));
-       return hashindex;
-}
-
-void expairseq::shrink_hashtab()
-{
-       unsigned new_hashtabsize;
-       while (hashtabsize!=(new_hashtabsize=calc_hashtabsize(seq.size()))) {
-               GINAC_ASSERT(new_hashtabsize<hashtabsize);
-               if (new_hashtabsize==0) {
-                       hashtab.clear();
-                       hashtabsize = 0;
-                       canonicalize();
-                       return;
-               }
-               
-               // shrink by a factor of 2
-               unsigned half_hashtabsize = hashtabsize/2;
-               for (unsigned i=0; i<half_hashtabsize-1; ++i)
-                       hashtab[i].merge(hashtab[i+half_hashtabsize],epp_is_less());
-               // special treatment for numeric hashes
-               hashtab[0].merge(hashtab[half_hashtabsize-1],epp_is_less());
-               hashtab[half_hashtabsize-1] = hashtab[hashtabsize-1];
-               hashtab.resize(half_hashtabsize);
-               hashtabsize = half_hashtabsize;
-               hashmask = hashtabsize-1;
-       }
-}
-
-void expairseq::remove_hashtab_entry(epvector::const_iterator element)
-{
-       if (hashtabsize==0)
-               return; // nothing to do
-       
-       // calculate hashindex of element to be deleted
-       unsigned hashindex = calc_hashindex((*element).rest);
-
-       // find it in hashtab and remove it
-       epplist &eppl = hashtab[hashindex];
-       epplist::iterator epplit = eppl.begin();
-       bool erased = false;
-       while (epplit!=eppl.end()) {
-               if (*epplit == element) {
-                       eppl.erase(epplit);
-                       erased = true;
-                       break;
-               }
-               ++epplit;
-       }
-       if (!erased) {
-               std::cout << "tried to erase " << element-seq.begin() << std::endl;
-               std::cout << "size " << seq.end()-seq.begin() << std::endl;
-
-               unsigned hashindex = calc_hashindex(element->rest);
-               epplist &eppl = hashtab[hashindex];
-               epplist::iterator epplit = eppl.begin();
-               bool erased = false;
-               while (epplit!=eppl.end()) {
-                       if (*epplit == element) {
-                               eppl.erase(epplit);
-                               erased = true;
-                               break;
-                       }
-                       ++epplit;
-               }
-               GINAC_ASSERT(erased);
-       }
-       GINAC_ASSERT(erased);
-}
-
-void expairseq::move_hashtab_entry(epvector::const_iterator oldpos,
-                                   epvector::iterator newpos)
-{
-       GINAC_ASSERT(hashtabsize!=0);
-       
-       // calculate hashindex of element which was moved
-       unsigned hashindex=calc_hashindex((*newpos).rest);
-
-       // find it in hashtab and modify it
-       epplist &eppl = hashtab[hashindex];
-       epplist::iterator epplit = eppl.begin();
-       while (epplit!=eppl.end()) {
-               if (*epplit == oldpos) {
-                       *epplit = newpos;
-                       break;
-               }
-               ++epplit;
-       }
-       GINAC_ASSERT(epplit!=eppl.end());
-}
-
-void expairseq::sorted_insert(epplist &eppl, epvector::const_iterator elem)
-{
-       epplist::const_iterator current = eppl.begin();
-       while ((current!=eppl.end()) && ((*current)->is_less(*elem))) {
-               ++current;
-       }
-       eppl.insert(current,elem);
-}    
-
-void expairseq::build_hashtab_and_combine(epvector::iterator &first_numeric,
-                                          epvector::iterator &last_non_zero,
-                                          std::vector<bool> &touched,
-                                          unsigned &number_of_zeroes)
-{
-       epp current = seq.begin();
-
-       while (current!=first_numeric) {
-               if (is_exactly_a<numeric>(current->rest)) {
-                       --first_numeric;
-                       iter_swap(current,first_numeric);
-               } else {
-                       // calculate hashindex
-                       unsigned currenthashindex = calc_hashindex(current->rest);
-
-                       // test if there is already a matching expair in the hashtab-list
-                       epplist &eppl=hashtab[currenthashindex];
-                       epplist::iterator epplit = eppl.begin();
-                       while (epplit!=eppl.end()) {
-                               if (current->rest.is_equal((*epplit)->rest))
-                                       break;
-                               ++epplit;
-                       }
-                       if (epplit==eppl.end()) {
-                               // no matching expair found, append this to end of list
-                               sorted_insert(eppl,current);
-                               ++current;
-                       } else {
-                               // epplit points to a matching expair, combine it with current
-                               (*epplit)->coeff = ex_to<numeric>((*epplit)->coeff).
-                                                  add_dyn(ex_to<numeric>(current->coeff));
-                               
-                               // move obsolete current expair to end by swapping with last_non_zero element
-                               // if this was a numeric, it is swapped with the expair before first_numeric 
-                               iter_swap(current,last_non_zero);
-                               --first_numeric;
-                               if (first_numeric!=last_non_zero) iter_swap(first_numeric,current);
-                               --last_non_zero;
-                               ++number_of_zeroes;
-                               // test if combined term has coeff 0 and can be removed is done later
-                               touched[(*epplit)-seq.begin()] = true;
-                       }
-               }
-       }
-}
-
-void expairseq::drop_coeff_0_terms(epvector::iterator &first_numeric,
-                                   epvector::iterator &last_non_zero,
-                                   std::vector<bool> &touched,
-                                   unsigned &number_of_zeroes)
-{
-       // move terms with coeff 0 to end and remove them from hashtab
-       // check only those elements which have been touched
-       epp current = seq.begin();
-       size_t i = 0;
-       while (current!=first_numeric) {
-               if (!touched[i]) {
-                       ++current;
-                       ++i;
-               } else if (!ex_to<numeric>((*current).coeff).is_zero()) {
-                       ++current;
-                       ++i;
-               } else {
-                       remove_hashtab_entry(current);
-                       
-                       // move element to the end, unless it is already at the end
-                       if (current!=last_non_zero) {
-                               iter_swap(current,last_non_zero);
-                               --first_numeric;
-                               bool numeric_swapped = first_numeric!=last_non_zero;
-                               if (numeric_swapped)
-                                       iter_swap(first_numeric,current);
-                               epvector::iterator changed_entry;
-
-                               if (numeric_swapped)
-                                       changed_entry = first_numeric;
-                               else
-                                       changed_entry = last_non_zero;
-                               
-                               --last_non_zero;
-                               ++number_of_zeroes;
-
-                               if (first_numeric!=current) {
-
-                                       // change entry in hashtab which referred to first_numeric or last_non_zero to current
-                                       move_hashtab_entry(changed_entry,current);
-                                       touched[current-seq.begin()] = touched[changed_entry-seq.begin()];
-                               }
-                       } else {
-                               --first_numeric;
-                               --last_non_zero;
-                               ++number_of_zeroes;
-                       }
-               }
-       }
-       GINAC_ASSERT(i==current-seq.begin());
-}
-
-/** True if one of the coeffs vanishes, otherwise false.
- *  This would be an invariant violation, so this should only be used for
- *  debugging purposes. */
-bool expairseq::has_coeff_0() const
-{
-       epvector::const_iterator i = seq.begin(), end = seq.end();
-       while (i != end) {
-               if (i->coeff.is_zero())
-                       return true;
-               ++i;
-       }
-       return false;
-}
-
-void expairseq::add_numerics_to_hashtab(epvector::iterator first_numeric,
-                                                                               epvector::const_iterator last_non_zero)
-{
-       if (first_numeric == seq.end()) return; // no numerics
-       
-       epvector::const_iterator current = first_numeric, last = last_non_zero + 1;
-       while (current != last) {
-               sorted_insert(hashtab[hashmask], current);
-               ++current;
-       }
-}
-
-void expairseq::combine_same_terms()
-{
-       // combine same terms, drop term with coeff 0, move numerics to end
-       
-       // calculate size of hashtab
-       hashtabsize = calc_hashtabsize(seq.size());
-       
-       // hashtabsize is a power of 2
-       hashmask = hashtabsize-1;
-       
-       // allocate hashtab
-       hashtab.clear();
-       hashtab.resize(hashtabsize);
-       
-       if (hashtabsize==0) {
-               canonicalize();
-               combine_same_terms_sorted_seq();
-               GINAC_ASSERT(!has_coeff_0());
-               return;
-       }
-       
-       // iterate through seq, move numerics to end,
-       // fill hashtab and combine same terms
-       epvector::iterator first_numeric = seq.end();
-       epvector::iterator last_non_zero = seq.end()-1;
-       
-       size_t num = seq.size();
-       std::vector<bool> touched(num);
-       
-       unsigned number_of_zeroes = 0;
-       
-       GINAC_ASSERT(!has_coeff_0());
-       build_hashtab_and_combine(first_numeric,last_non_zero,touched,number_of_zeroes);
-       
-       // there should not be any terms with coeff 0 from the beginning,
-       // so it should be safe to skip this step
-       if (number_of_zeroes!=0) {
-               drop_coeff_0_terms(first_numeric,last_non_zero,touched,number_of_zeroes);
-       }
-       
-       add_numerics_to_hashtab(first_numeric,last_non_zero);
-       
-       // pop zero elements
-       for (unsigned i=0; i<number_of_zeroes; ++i) {
-               seq.pop_back();
-       }
-       
-       // shrink hashtabsize to calculated value
-       GINAC_ASSERT(!has_coeff_0());
-       
-       shrink_hashtab();
-       
-       GINAC_ASSERT(!has_coeff_0());
-}
-
-#endif // EXPAIRSEQ_USE_HASHTAB
-
 /** Check if this expairseq is in sorted (canonical) form.  Useful mainly for
  *  debugging or in assertions since being sorted is an invariance. */
 bool expairseq::is_canonical() const
@@ -1484,10 +1002,6 @@ bool expairseq::is_canonical() const
        if (seq.size() <= 1)
                return 1;
        
-#if EXPAIRSEQ_USE_HASHTAB
-       if (hashtabsize > 0) return 1; // not canoncalized
-#endif // EXPAIRSEQ_USE_HASHTAB
-       
        epvector::const_iterator it = seq.begin(), itend = seq.end();
        epvector::const_iterator it_last = it;
        for (++it; it!=itend; it_last=it, ++it) {
@@ -1614,68 +1128,6 @@ std::auto_ptr<epvector> expairseq::evalchildren(int level) const
        return std::auto_ptr<epvector>(0); // signalling nothing has changed
 }
 
-class safe_inserter
-{
-       public:
-               safe_inserter(const ex&, const bool disable_renaming=false);
-               std::auto_ptr<epvector> getseq(){return epv;}
-               void insert_old_pair(const expair &p)
-               {
-                       epv->push_back(p);
-               }
-               void insert_new_pair(const expair &p, const ex &orig_ex);
-       private:
-               std::auto_ptr<epvector> epv;
-               bool dodummies;
-               exvector dummy_indices;
-               void update_dummy_indices(const exvector&);
-};
-
-safe_inserter::safe_inserter(const ex&e, const bool disable_renaming)
-               :epv(new epvector)
-{
-       epv->reserve(e.nops());
-       dodummies=is_a<mul>(e);
-       if(disable_renaming)
-               dodummies=false;
-       if(dodummies) {
-               dummy_indices = get_all_dummy_indices_safely(e);
-               sort(dummy_indices.begin(), dummy_indices.end(), ex_is_less());
-       }
-}
-
-void safe_inserter::update_dummy_indices(const exvector &v)
-{
-       exvector new_dummy_indices;
-       set_union(dummy_indices.begin(), dummy_indices.end(), v.begin(), v.end(),
-               std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-       dummy_indices.swap(new_dummy_indices);
-}
-
-void safe_inserter::insert_new_pair(const expair &p, const ex &orig_ex)
-{
-       if(!dodummies) {
-               epv->push_back(p);
-               return;
-       }
-       exvector dummies_of_factor = get_all_dummy_indices_safely(p.rest);
-       if(dummies_of_factor.size() == 0) {
-               epv->push_back(p);
-               return;
-       }
-       sort(dummies_of_factor.begin(), dummies_of_factor.end(), ex_is_less());
-       exvector dummies_of_orig_ex = get_all_dummy_indices_safely(orig_ex);
-       sort(dummies_of_orig_ex.begin(), dummies_of_orig_ex.end(), ex_is_less());
-       exvector new_dummy_indices;
-       new_dummy_indices.reserve(dummy_indices.size());
-       set_difference(dummy_indices.begin(), dummy_indices.end(), dummies_of_orig_ex.begin(), dummies_of_orig_ex.end(),
-               std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-       dummy_indices.swap(new_dummy_indices);
-       ex newfactor = rename_dummy_indices_uniquely(dummy_indices, dummies_of_factor, p.rest);
-       update_dummy_indices(dummies_of_factor);
-       epv -> push_back(expair(newfactor, p.coeff));
-}
-
 /** Member-wise substitute in this sequence.
  *
  *  @see expairseq::subs()
@@ -1710,27 +1162,22 @@ std::auto_ptr<epvector> expairseq::subschildren(const exmap & m, unsigned option
                        if (!are_ex_trivially_equal(orig_ex, subsed_ex)) {
 
                                // Something changed, copy seq, subs and return it
-                               safe_inserter s(*this, options & subs_options::no_index_renaming);
+                               std::auto_ptr<epvector> s(new epvector);
+                               s->reserve(seq.size());
 
                                // Copy parts of seq which are known not to have changed
-                               for(epvector::const_iterator i=seq.begin(); i!=cit; ++i)
-                                       s.insert_old_pair(*i);
+                               s->insert(s->begin(), seq.begin(), cit);
 
                                // Copy first changed element
-                               s.insert_new_pair(split_ex_to_pair(subsed_ex), orig_ex);
+                               s->push_back(split_ex_to_pair(subsed_ex));
                                ++cit;
 
                                // Copy rest
                                while (cit != last) {
-                                       ex orig_ex = recombine_pair_to_ex(*cit);
-                                       ex subsed_ex = orig_ex.subs(m, options);
-                                       if(are_ex_trivially_equal(orig_ex, subsed_ex))
-                                               s.insert_old_pair(*cit);
-                                       else
-                                               s.insert_new_pair(split_ex_to_pair(subsed_ex), orig_ex);
+                                       s->push_back(split_ex_to_pair(recombine_pair_to_ex(*cit).subs(m, options)));
                                        ++cit;
                                }
-                               return s.getseq();
+                               return s;
                        }
 
                        ++cit;
@@ -1746,27 +1193,22 @@ std::auto_ptr<epvector> expairseq::subschildren(const exmap & m, unsigned option
                        if (!are_ex_trivially_equal(cit->rest, subsed_ex)) {
                        
                                // Something changed, copy seq, subs and return it
-                               safe_inserter s(*this, options & subs_options::no_index_renaming);
+                               std::auto_ptr<epvector> s(new epvector);
+                               s->reserve(seq.size());
 
                                // Copy parts of seq which are known not to have changed
-                               for(epvector::const_iterator i=seq.begin(); i!=cit; ++i)
-                                       s.insert_old_pair(*i);
+                               s->insert(s->begin(), seq.begin(), cit);
                        
                                // Copy first changed element
-                               s.insert_new_pair(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff), cit->rest);
+                               s->push_back(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff));
                                ++cit;
 
                                // Copy rest
                                while (cit != last) {
-                                       const ex &orig_ex = cit->rest;
-                                       const ex &subsed_ex = cit->rest.subs(m, options);
-                                       if(are_ex_trivially_equal(orig_ex, subsed_ex))
-                                               s.insert_old_pair(*cit);
-                                       else
-                                               s.insert_new_pair(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff), orig_ex);
+                                       s->push_back(combine_ex_with_coeff_to_pair(cit->rest.subs(m, options), cit->coeff));
                                        ++cit;
                                }
-                               return s.getseq();
+                               return s;
                        }
 
                        ++cit;
@@ -1781,10 +1223,4 @@ std::auto_ptr<epvector> expairseq::subschildren(const exmap & m, unsigned option
 // static member variables
 //////////
 
-#if EXPAIRSEQ_USE_HASHTAB
-unsigned expairseq::maxhashtabsize = 0x4000000U;
-unsigned expairseq::minhashtabsize = 0x1000U;
-unsigned expairseq::hashtabfactor = 1;
-#endif // EXPAIRSEQ_USE_HASHTAB
-
 } // namespace GiNaC