]> www.ginac.de Git - ginac.git/blobdiff - ginac/expairseq.cpp
* expairseq::expairseq(const epvector&, const ex& oc) (expairseq.cpp):
[ginac.git] / ginac / expairseq.cpp
index 86f687de42879f3ba9c08238b1c16e51d8b904b0..b233fe2973ea2f297441d66657d3b70536c52d0b 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of sequences of expression pairs. */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2002 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <iostream>
 #include <algorithm>
 #include <string>
 #include <stdexcept>
 
 #include "expairseq.h"
 #include "lst.h"
+#include "mul.h"
+#include "power.h"
 #include "relational.h"
+#include "wildcard.h"
 #include "print.h"
 #include "archive.h"
-#include "debugmsg.h"
 #include "utils.h"
 
 #if EXPAIRSEQ_USE_HASHTAB
@@ -38,6 +41,7 @@
 
 namespace GiNaC {
 
+       
 GINAC_IMPLEMENT_REGISTERED_CLASS_NO_CTORS(expairseq, basic)
 
 //////////
@@ -54,20 +58,18 @@ public:
 };
 
 //////////
-// default ctor, dtor, copy ctor assignment operator and helpers
+// default ctor, dtor, copy ctor, assignment operator and helpers
 //////////
 
 // public
 
 expairseq::expairseq(const expairseq &other)
 {
-       debugmsg("expairseq copy ctor",LOGLEVEL_CONSTRUCT);
        copy(other);
 }
 
 const expairseq &expairseq::operator=(const expairseq &other)
 {
-       debugmsg("expairseq operator=",LOGLEVEL_ASSIGNMENT);
        if (this != &other) {
                destroy(true);
                copy(other);
@@ -111,14 +113,12 @@ DEFAULT_DESTROY(expairseq)
 
 expairseq::expairseq(const ex &lh, const ex &rh) : inherited(TINFO_expairseq)
 {
-       debugmsg("expairseq ctor from ex,ex",LOGLEVEL_CONSTRUCT);
        construct_from_2_ex(lh,rh);
        GINAC_ASSERT(is_canonical());
 }
 
 expairseq::expairseq(const exvector &v) : inherited(TINFO_expairseq)
 {
-       debugmsg("expairseq ctor from exvector",LOGLEVEL_CONSTRUCT);
        construct_from_exvector(v);
        GINAC_ASSERT(is_canonical());
 }
@@ -126,7 +126,7 @@ expairseq::expairseq(const exvector &v) : inherited(TINFO_expairseq)
 expairseq::expairseq(const epvector &v, const ex &oc)
   : inherited(TINFO_expairseq), overall_coeff(oc)
 {
-       debugmsg("expairseq ctor from epvector,ex",LOGLEVEL_CONSTRUCT);
+       GINAC_ASSERT(is_a<numeric>(oc));
        construct_from_epvector(v);
        GINAC_ASSERT(is_canonical());
 }
@@ -134,8 +134,8 @@ expairseq::expairseq(const epvector &v, const ex &oc)
 expairseq::expairseq(epvector *vp, const ex &oc)
   : inherited(TINFO_expairseq), overall_coeff(oc)
 {
-       debugmsg("expairseq ctor from epvector *,ex",LOGLEVEL_CONSTRUCT);
        GINAC_ASSERT(vp!=0);
+       GINAC_ASSERT(is_a<numeric>(oc));
        construct_from_epvector(*vp);
        delete vp;
        GINAC_ASSERT(is_canonical());
@@ -150,7 +150,6 @@ expairseq::expairseq(const archive_node &n, const lst &sym_lst) : inherited(n, s
        , hashtabsize(0)
 #endif
 {
-       debugmsg("expairseq ctor from archive_node", LOGLEVEL_CONSTRUCT);
        for (unsigned int i=0; true; i++) {
                ex rest;
                ex coeff;
@@ -177,21 +176,18 @@ void expairseq::archive(archive_node &n) const
 DEFAULT_UNARCHIVE(expairseq)
 
 //////////
-// functions overriding virtual functions from bases classes
+// functions overriding virtual functions from base classes
 //////////
 
 // public
 
 basic *expairseq::duplicate() const
 {
-       debugmsg("expairseq duplicate",LOGLEVEL_DUPLICATE);
        return new expairseq(*this);
 }
 
-void expairseq::print(const print_context & c, unsigned level) const
+void expairseq::print(const print_context &c, unsigned level) const
 {
-       debugmsg("expairseq print",LOGLEVEL_PRINT);
-
        if (is_of_type(c, print_tree)) {
 
                unsigned delta_indent = static_cast<const print_tree &>(c).delta_indent;
@@ -200,10 +196,11 @@ void expairseq::print(const print_context & c, unsigned level) const
                    << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
                    << ", nops=" << nops()
                    << std::endl;
-               for (unsigned i=0; i<seq.size(); ++i) {
+               unsigned num = seq.size();
+               for (unsigned i=0; i<num; ++i) {
                        seq[i].rest.print(c, level + delta_indent);
                        seq[i].coeff.print(c, level + delta_indent);
-                       if (i != seq.size()-1)
+                       if (i != num - 1)
                                c.s << std::string(level + delta_indent, ' ') << "-----" << std::endl;
                }
                if (!overall_coeff.is_equal(default_overall_coeff())) {
@@ -233,7 +230,7 @@ void expairseq::print(const print_context & c, unsigned level) const
                                        c.s << *it-seq.begin() << " ";
                                        ++this_bin_fill;
                                }
-                               os << std::endl;
+                               c.s << std::endl;
                                cum_fill += this_bin_fill;
                                cum_fill_sq += this_bin_fill*this_bin_fill;
                        }
@@ -299,7 +296,7 @@ ex &expairseq::let_op(int i)
        throw(std::logic_error("let_op not defined for expairseq and derived classes (add,mul,...)"));
 }
 
-ex expairseq::map(map_function & f) const
+ex expairseq::map(map_function &f) const
 {
        epvector *v = new epvector;
        v->reserve(seq.size());
@@ -307,12 +304,16 @@ ex expairseq::map(map_function & f) const
        epvector::const_iterator cit = seq.begin(), last = seq.end();
        while (cit != last) {
                v->push_back(split_ex_to_pair(f(recombine_pair_to_ex(*cit))));
-               cit++;
+               ++cit;
        }
 
-       return thisexpairseq(v, f(overall_coeff));
+       if (overall_coeff.is_equal(default_overall_coeff()))
+               return thisexpairseq(v, default_overall_coeff());
+       else
+               return thisexpairseq(v, f(overall_coeff));
 }
 
+/** Perform coefficient-wise automatic term rewriting rules in this class. */
 ex expairseq::eval(int level) const
 {
        if ((level==1) && (flags &status_flags::evaluated))
@@ -325,23 +326,12 @@ ex expairseq::eval(int level) const
        return (new expairseq(vp,overall_coeff))->setflag(status_flags::dynallocated | status_flags::evaluated);
 }
 
-ex expairseq::evalf(int level) const
-{
-       return thisexpairseq(evalfchildren(level),overall_coeff.evalf(level-1));
-}
-
-ex expairseq::normal(lst &sym_lst, lst &repl_lst, int level) const
-{
-       ex n = thisexpairseq(normalchildren(level),overall_coeff);
-       return n.bp->basic::normal(sym_lst,repl_lst,level);
-}
-
 bool expairseq::match(const ex & pattern, lst & 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 (tinfo() == pattern.bp->tinfo()) {
+       if (this->tinfo() == ex_to<basic>(pattern).tinfo()) {
 
                // Check whether global wildcard (one that matches the "rest of the
                // expression", like "*" above) is present
@@ -376,7 +366,7 @@ bool expairseq::match(const ex & pattern, lst & repl_lst) const
                                        ops.erase(it);
                                        goto found;
                                }
-                               it++;
+                               ++it;
                        }
                        return false; // no match found
 found:         ;
@@ -387,14 +377,15 @@ found:            ;
                        // Assign all the remaining terms to the global wildcard (unless
                        // it has already been matched before, in which case the matches
                        // must be equal)
+                       unsigned num = ops.size();
                        epvector *vp = new epvector();
-                       vp->reserve(ops.size());
-                       for (unsigned i=0; i<ops.size(); i++)
+                       vp->reserve(num);
+                       for (unsigned i=0; i<num; i++)
                                vp->push_back(split_ex_to_pair(ops[i]));
                        ex rest = thisexpairseq(vp, default_overall_coeff());
                        for (unsigned i=0; i<repl_lst.nops(); i++) {
                                if (repl_lst.op(i).op(0).is_equal(global_wildcard))
-                                       return rest.is_equal(*repl_lst.op(i).op(1).bp);
+                                       return rest.is_equal(repl_lst.op(i).op(1));
                        }
                        repl_lst.append(global_wildcard == rest);
                        return true;
@@ -413,24 +404,16 @@ ex expairseq::subs(const lst &ls, const lst &lr, bool no_pattern) const
 {
        epvector *vp = subschildren(ls, lr, no_pattern);
        if (vp)
-               return thisexpairseq(vp, overall_coeff).bp->basic::subs(ls, lr, no_pattern);
+               return ex_to<basic>(thisexpairseq(vp, overall_coeff));
        else
                return basic::subs(ls, lr, no_pattern);
 }
 
 // protected
 
-/** Implementation of ex::diff() for an expairseq.
- *  It differentiates all elements of the sequence.
- *  @see ex::diff */
-ex expairseq::derivative(const symbol &s) const
-{
-       return thisexpairseq(diffchildren(s),overall_coeff);
-}
-
 int expairseq::compare_same_type(const basic &other) const
 {
-       GINAC_ASSERT(is_of_type(other, expairseq));
+       GINAC_ASSERT(is_a<expairseq>(other));
        const expairseq &o = static_cast<const expairseq &>(other);
        
        int cmpval;
@@ -565,16 +548,18 @@ unsigned expairseq::return_type(void) const
 
 unsigned expairseq::calchash(void) const
 {
-       unsigned v = golden_ratio_hash(tinfo());
-       for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
+       unsigned v = golden_ratio_hash(this->tinfo());
+       epvector::const_iterator i = seq.begin(), end = seq.end();
+       while (i != end) {
 #if !EXPAIRSEQ_USE_HASHTAB
                v = rotate_left_31(v); // rotation would spoil commutativity
 #endif // EXPAIRSEQ_USE_HASHTAB
-               v ^= cit->rest.gethash();
+               v ^= i->rest.gethash();
 #if !EXPAIRSEQ_USE_HASHTAB
                v = rotate_left_31(v);
-               v ^= cit->coeff.gethash();
+               v ^= i->coeff.gethash();
 #endif // EXPAIRSEQ_USE_HASHTAB
+               ++i;
        }
        
        v ^= overall_coeff.gethash();
@@ -592,13 +577,11 @@ unsigned expairseq::calchash(void) const
 ex expairseq::expand(unsigned options) const
 {
        epvector *vp = expandchildren(options);
-       if (vp==0) {
-               // the terms have not changed, so it is safe to declare this expanded
-               setflag(status_flags::expanded);
-               return *this;
-       }
-       
-       return thisexpairseq(vp,overall_coeff);
+       if (vp == NULL) {
+               // The terms have not changed, so it is safe to declare this expanded
+               return (options == 0) ? setflag(status_flags::expanded) : *this;
+       } else
+               return thisexpairseq(vp, overall_coeff);
 }
 
 //////////
@@ -628,9 +611,9 @@ ex expairseq::thisexpairseq(epvector *vp, const ex &oc) const
 void expairseq::printpair(const print_context & c, const expair & p, unsigned upper_precedence) const
 {
        c.s << "[[";
-       p.rest.bp->print(c, precedence());
+       p.rest.print(c, precedence());
        c.s << ",";
-       p.coeff.bp->print(c, precedence());
+       p.coeff.print(c, precedence());
        c.s << "]]";
 }
 
@@ -660,14 +643,14 @@ void expairseq::printseq(const print_context & c, char delim,
  *  @see expairseq::recombine_pair_to_ex() */
 expair expairseq::split_ex_to_pair(const ex &e) const
 {
-       return expair(e,_ex1());
+       return expair(e,_ex1);
 }
 
 
 expair expairseq::combine_ex_with_coeff_to_pair(const ex &e,
                                                 const ex &c) const
 {
-       GINAC_ASSERT(is_ex_exactly_of_type(c,numeric));
+       GINAC_ASSERT(is_exactly_a<numeric>(c));
        
        return expair(e,c);
 }
@@ -676,8 +659,8 @@ expair expairseq::combine_ex_with_coeff_to_pair(const ex &e,
 expair expairseq::combine_pair_with_coeff_to_pair(const expair &p,
                                                   const ex &c) const
 {
-       GINAC_ASSERT(is_ex_exactly_of_type(p.coeff,numeric));
-       GINAC_ASSERT(is_ex_exactly_of_type(c,numeric));
+       GINAC_ASSERT(is_exactly_a<numeric>(p.coeff));
+       GINAC_ASSERT(is_exactly_a<numeric>(c));
        
        return expair(p.rest,ex_to<numeric>(p.coeff).mul_dyn(ex_to<numeric>(c)));
 }
@@ -700,21 +683,21 @@ bool expairseq::expair_needs_further_processing(epp it)
 
 ex expairseq::default_overall_coeff(void) const
 {
-       return _ex0();
+       return _ex0;
 }
 
 void expairseq::combine_overall_coeff(const ex &c)
 {
-       GINAC_ASSERT(is_ex_exactly_of_type(overall_coeff,numeric));
-       GINAC_ASSERT(is_ex_exactly_of_type(c,numeric));
+       GINAC_ASSERT(is_exactly_a<numeric>(overall_coeff));
+       GINAC_ASSERT(is_exactly_a<numeric>(c));
        overall_coeff = ex_to<numeric>(overall_coeff).add_dyn(ex_to<numeric>(c));
 }
 
 void expairseq::combine_overall_coeff(const ex &c1, const ex &c2)
 {
-       GINAC_ASSERT(is_ex_exactly_of_type(overall_coeff,numeric));
-       GINAC_ASSERT(is_ex_exactly_of_type(c1,numeric));
-       GINAC_ASSERT(is_ex_exactly_of_type(c2,numeric));
+       GINAC_ASSERT(is_exactly_a<numeric>(overall_coeff));
+       GINAC_ASSERT(is_exactly_a<numeric>(c1));
+       GINAC_ASSERT(is_exactly_a<numeric>(c2));
        overall_coeff = ex_to<numeric>(overall_coeff).
                        add_dyn(ex_to<numeric>(c1).mul(ex_to<numeric>(c2)));
 }
@@ -744,8 +727,8 @@ void expairseq::construct_from_2_ex_via_exvector(const ex &lh, const ex &rh)
 
 void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
 {
-       if (lh.bp->tinfo()==tinfo()) {
-               if (rh.bp->tinfo()==tinfo()) {
+       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();
@@ -772,7 +755,7 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
 #endif // EXPAIRSEQ_USE_HASHTAB
                        return;
                }
-       } else if (rh.bp->tinfo()==tinfo()) {
+       } 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) {
@@ -812,7 +795,7 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
                        
                        int cmpval = p1.rest.compare(p2.rest);
                        if (cmpval==0) {
-                               p1.coeff=ex_to<numeric>(p1.coeff).add_dyn(ex_to<numeric>(p2.coeff));
+                               p1.coeff = ex_to<numeric>(p1.coeff).add_dyn(ex_to<numeric>(p2.coeff));
                                if (!ex_to<numeric>(p1.coeff).is_zero()) {
                                        // no further processing is necessary, since this
                                        // one element will usually be recombined in eval()
@@ -851,10 +834,10 @@ void expairseq::construct_from_2_expairseq(const expairseq &s1,
                int cmpval = (*first1).rest.compare((*first2).rest);
                if (cmpval==0) {
                        // combine terms
-                       const numeric &newcoeff = ex_to<numeric>((*first1).coeff).
-                                                  add(ex_to<numeric>((*first2).coeff));
+                       const numeric &newcoeff = ex_to<numeric>(first1->coeff).
+                                                  add(ex_to<numeric>(first2->coeff));
                        if (!newcoeff.is_zero()) {
-                               seq.push_back(expair((*first1).rest,newcoeff));
+                               seq.push_back(expair(first1->rest,newcoeff));
                                if (expair_needs_further_processing(seq.end()-1)) {
                                        needs_further_processing = true;
                                }
@@ -907,16 +890,15 @@ void expairseq::construct_from_expairseq_ex(const expairseq &s,
        
        // merge p into s.seq
        while (first!=last) {
-               int cmpval=(*first).rest.compare(p.rest);
+               int cmpval = (*first).rest.compare(p.rest);
                if (cmpval==0) {
                        // combine terms
-                       const numeric &newcoeff = ex_to<numeric>((*first).coeff).
+                       const numeric &newcoeff = ex_to<numeric>(first->coeff).
                                                   add(ex_to<numeric>(p.coeff));
                        if (!newcoeff.is_zero()) {
-                               seq.push_back(expair((*first).rest,newcoeff));
-                               if (expair_needs_further_processing(seq.end()-1)) {
+                               seq.push_back(expair(first->rest,newcoeff));
+                               if (expair_needs_further_processing(seq.end()-1))
                                        needs_further_processing = true;
-                               }
                        }
                        ++first;
                        p_pushed = true;
@@ -963,7 +945,6 @@ void expairseq::construct_from_exvector(const exvector &v)
        canonicalize();
        combine_same_terms_sorted_seq();
 #endif // EXPAIRSEQ_USE_HASHTAB
-       return;
 }
 
 void expairseq::construct_from_epvector(const epvector &v)
@@ -980,7 +961,6 @@ void expairseq::construct_from_epvector(const epvector &v)
        canonicalize();
        combine_same_terms_sorted_seq();
 #endif // EXPAIRSEQ_USE_HASHTAB
-       return;
 }
 
 /** Combine this expairseq with argument exvector.
@@ -996,7 +976,7 @@ void expairseq::make_flat(const exvector &v)
        
        cit = v.begin();
        while (cit!=v.end()) {
-               if (cit->bp->tinfo()==this->tinfo()) {
+               if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
                        ++nexpairseqs;
                        noperands += ex_to<expairseq>(*cit).seq.size();
                }
@@ -1009,7 +989,7 @@ void expairseq::make_flat(const exvector &v)
        // copy elements and split off numerical part
        cit = v.begin();
        while (cit!=v.end()) {
-               if (cit->bp->tinfo()==this->tinfo()) {
+               if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
                        const expairseq &subseqref = ex_to<expairseq>(*cit);
                        combine_overall_coeff(subseqref.overall_coeff);
                        epvector::const_iterator cit_s = subseqref.seq.begin();
@@ -1025,8 +1005,6 @@ void expairseq::make_flat(const exvector &v)
                }
                ++cit;
        }
-       
-       return;
 }
 
 /** Combine this expairseq with argument epvector.
@@ -1042,9 +1020,9 @@ void expairseq::make_flat(const epvector &v)
        
        cit = v.begin();
        while (cit!=v.end()) {
-               if (cit->rest.bp->tinfo()==this->tinfo()) {
+               if (ex_to<basic>(cit->rest).tinfo()==this->tinfo()) {
                        ++nexpairseqs;
-                       noperands += ex_to<expairseq>((*cit).rest).seq.size();
+                       noperands += ex_to<expairseq>(cit->rest).seq.size();
                }
                ++cit;
        }
@@ -1055,15 +1033,15 @@ void expairseq::make_flat(const epvector &v)
        // copy elements and split off numerical part
        cit = v.begin();
        while (cit!=v.end()) {
-               if (cit->rest.bp->tinfo()==this->tinfo() &&
+               if (ex_to<basic>(cit->rest).tinfo()==this->tinfo() &&
                    this->can_make_flat(*cit)) {
-                       const expairseq &subseqref = ex_to<expairseq>((*cit).rest);
+                       const expairseq &subseqref = ex_to<expairseq>(cit->rest);
                        combine_overall_coeff(ex_to<numeric>(subseqref.overall_coeff),
-                                                           ex_to<numeric>((*cit).coeff));
+                                                           ex_to<numeric>(cit->coeff));
                        epvector::const_iterator cit_s = subseqref.seq.begin();
                        while (cit_s!=subseqref.seq.end()) {
-                               seq.push_back(expair((*cit_s).rest,
-                                                    ex_to<numeric>((*cit_s).coeff).mul_dyn(ex_to<numeric>((*cit).coeff))));
+                               seq.push_back(expair(cit_s->rest,
+                                                    ex_to<numeric>(cit_s->coeff).mul_dyn(ex_to<numeric>(cit->coeff))));
                                //seq.push_back(combine_pair_with_coeff_to_pair(*cit_s,
                                //                                              (*cit).coeff));
                                ++cit_s;
@@ -1076,15 +1054,12 @@ void expairseq::make_flat(const epvector &v)
                }
                ++cit;
        }
-       return;
 }
 
 /** Brings this expairseq into a sorted (canonical) form. */
 void expairseq::canonicalize(void)
 {
-       // canonicalize
-       sort(seq.begin(),seq.end(),expair_is_less());
-       return;
+       std::sort(seq.begin(), seq.end(), expair_rest_is_less());
 }
 
 
@@ -1104,14 +1079,14 @@ void expairseq::combine_same_terms_sorted_seq(void)
                // possible from then on the sequence has changed and must be compacted
                bool must_copy = false;
                while (itin2!=last) {
-                       if ((*itin1).rest.compare((*itin2).rest)==0) {
-                               (*itin1).coeff = ex_to<numeric>((*itin1).coeff).
-                                                add_dyn(ex_to<numeric>((*itin2).coeff));
+                       if (itin1->rest.compare(itin2->rest)==0) {
+                               itin1->coeff = ex_to<numeric>(itin1->coeff).
+                                              add_dyn(ex_to<numeric>(itin2->coeff));
                                if (expair_needs_further_processing(itin1))
                                        needs_further_processing = true;
                                must_copy = true;
                        } else {
-                               if (!ex_to<numeric>((*itin1).coeff).is_zero()) {
+                               if (!ex_to<numeric>(itin1->coeff).is_zero()) {
                                        if (must_copy)
                                                *itout = *itin1;
                                        ++itout;
@@ -1120,7 +1095,7 @@ void expairseq::combine_same_terms_sorted_seq(void)
                        }
                        ++itin2;
                }
-               if (!ex_to<numeric>((*itin1).coeff).is_zero()) {
+               if (!ex_to<numeric>(itin1->coeff).is_zero()) {
                        if (must_copy)
                                *itout = *itin1;
                        ++itout;
@@ -1134,7 +1109,6 @@ void expairseq::combine_same_terms_sorted_seq(void)
                seq.clear();
                construct_from_epvector(v);
        }
-       return;
 }
 
 #if EXPAIRSEQ_USE_HASHTAB
@@ -1217,14 +1191,13 @@ void expairseq::remove_hashtab_entry(epvector::const_iterator element)
                ++epplit;
        }
        if (!erased) {
-               printtree(cout,0);
-               cout << "tried to erase " << element-seq.begin() << std::endl;
-               cout << "size " << seq.end()-seq.begin() << std::endl;
+               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);
+               unsigned hashindex = calc_hashindex(element->rest);
                epplist &eppl = hashtab[hashindex];
-               epplist::iterator epplit=eppl.begin();
-               bool erased=false;
+               epplist::iterator epplit = eppl.begin();
+               bool erased = false;
                while (epplit!=eppl.end()) {
                        if (*epplit == element) {
                                eppl.erase(epplit);
@@ -1259,10 +1232,10 @@ void expairseq::move_hashtab_entry(epvector::const_iterator oldpos,
        GINAC_ASSERT(epplit!=eppl.end());
 }
 
-void expairseq::sorted_insert(epplist &eppl, epp elem)
+void expairseq::sorted_insert(epplist &eppl, epvector::const_iterator elem)
 {
-       epplist::iterator current = eppl.begin();
-       while ((current!=eppl.end())&&((*(*current)).is_less(*elem))) {
+       epplist::const_iterator current = eppl.begin();
+       while ((current!=eppl.end()) && ((*current)->is_less(*elem))) {
                ++current;
        }
        eppl.insert(current,elem);
@@ -1273,21 +1246,21 @@ void expairseq::build_hashtab_and_combine(epvector::iterator &first_numeric,
                                           std::vector<bool> &touched,
                                           unsigned &number_of_zeroes)
 {
-       epp current=seq.begin();
+       epp current = seq.begin();
 
        while (current!=first_numeric) {
-               if (is_ex_exactly_of_type((*current).rest,numeric)) {
+               if (is_ex_exactly_of_type(current->rest,numeric)) {
                        --first_numeric;
                        iter_swap(current,first_numeric);
                } else {
                        // calculate hashindex
-                       unsigned currenthashindex = calc_hashindex((*current).rest);
+                       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))
+                               if (current->rest.is_equal((*epplit)->rest))
                                        break;
                                ++epplit;
                        }
@@ -1297,8 +1270,8 @@ void expairseq::build_hashtab_and_combine(epvector::iterator &first_numeric,
                                ++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));
+                               (*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 
@@ -1308,7 +1281,7 @@ void expairseq::build_hashtab_and_combine(epvector::iterator &first_numeric,
                                --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;
+                               touched[(*epplit)-seq.begin()] = true;
                        }
                }
        }
@@ -1337,8 +1310,9 @@ void expairseq::drop_coeff_0_terms(epvector::iterator &first_numeric,
                        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);
+                               bool numeric_swapped = first_numeric!=last_non_zero;
+                               if (numeric_swapped)
+                                       iter_swap(first_numeric,current);
                                epvector::iterator changed_entry;
 
                                if (numeric_swapped)
@@ -1370,9 +1344,11 @@ void expairseq::drop_coeff_0_terms(epvector::iterator &first_numeric,
  *  debugging purposes. */
 bool expairseq::has_coeff_0(void) const
 {
-       for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
-               if ((*cit).coeff.is_zero())
+       epvector::const_iterator i = seq.begin(), end = seq.end();
+       while (i != end) {
+               if (i->coeff.is_zero())
                        return true;
+               ++i;
        }
        return false;
 }
@@ -1380,12 +1356,11 @@ bool expairseq::has_coeff_0(void) const
 void expairseq::add_numerics_to_hashtab(epvector::iterator first_numeric,
                                                                                epvector::const_iterator last_non_zero)
 {
-       if (first_numeric==seq.end()) return; // no numerics    
+       if (first_numeric == seq.end()) return; // no numerics
        
-       epvector::iterator current = first_numeric;
-       epvector::const_iterator last = last_non_zero+1;
-       while (current!=last) {
-               sorted_insert(hashtab[hashmask],current);
+       epvector::const_iterator current = first_numeric, last = last_non_zero + 1;
+       while (current != last) {
+               sorted_insert(hashtab[hashmask], current);
                ++current;
        }
 }
@@ -1416,41 +1391,18 @@ void expairseq::combine_same_terms(void)
        epvector::iterator first_numeric = seq.end();
        epvector::iterator last_non_zero = seq.end()-1;
        
-       std::vector<bool> touched;
-       touched.reserve(seq.size());
-       for (unsigned i=0; i<seq.size(); ++i) touched[i]=false;
+       unsigned 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);
-       /*
-       cout << "in combine:" << std::endl;
-       printtree(cout,0);
-       cout << "size=" << seq.end() - seq.begin() << std::endl;
-       cout << "first_numeric=" << first_numeric - seq.begin() << std::endl;
-       cout << "last_non_zero=" << last_non_zero - seq.begin() << std::endl;
-       for (unsigned i=0; i<seq.size(); ++i) {
-               if (touched[i]) cout << i << " is touched" << std::endl;
-       }
-       cout << "end in combine" << std::endl;
-       */
        
        // 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);
-               /*
-               cout << "in combine after drop:" << std::endl;
-               printtree(cout,0);
-               cout << "size=" << seq.end() - seq.begin() << std::endl;
-               cout << "first_numeric=" << first_numeric - seq.begin() << std::endl;
-               cout << "last_non_zero=" << last_non_zero - seq.begin() << std::endl;
-               for (unsigned i=0; i<seq.size(); ++i) {
-                       if (touched[i]) cout << i << " is touched" << std::endl;
-               }
-               cout << "end in combine after drop" << std::endl;
-               */
        }
        
        add_numerics_to_hashtab(first_numeric,last_non_zero);
@@ -1481,25 +1433,25 @@ bool expairseq::is_canonical() const
        if (hashtabsize > 0) return 1; // not canoncalized
 #endif // EXPAIRSEQ_USE_HASHTAB
        
-       epvector::const_iterator it = seq.begin();
+       epvector::const_iterator it = seq.begin(), itend = seq.end();
        epvector::const_iterator it_last = it;
-       for (++it; it!=seq.end(); it_last=it, ++it) {
-               if (!((*it_last).is_less(*it) || (*it_last).is_equal(*it))) {
-                       if (!is_ex_exactly_of_type((*it_last).rest,numeric) ||
-                               !is_ex_exactly_of_type((*it).rest,numeric)) {
+       for (++it; it!=itend; it_last=it, ++it) {
+               if (!(it_last->is_less(*it) || it_last->is_equal(*it))) {
+                       if (!is_ex_exactly_of_type(it_last->rest,numeric) ||
+                               !is_ex_exactly_of_type(it->rest,numeric)) {
                                // double test makes it easier to set a breakpoint...
-                               if (!is_ex_exactly_of_type((*it_last).rest,numeric) ||
-                                       !is_ex_exactly_of_type((*it).rest,numeric)) {
+                               if (!is_ex_exactly_of_type(it_last->rest,numeric) ||
+                                       !is_ex_exactly_of_type(it->rest,numeric)) {
                                        printpair(std::clog, *it_last, 0);
                                        std::clog << ">";
                                        printpair(std::clog, *it, 0);
                                        std::clog << "\n";
                                        std::clog << "pair1:" << std::endl;
-                                       (*it_last).rest.print(print_tree(std::clog));
-                                       (*it_last).coeff.print(print_tree(std::clog));
+                                       it_last->rest.print(print_tree(std::clog));
+                                       it_last->coeff.print(print_tree(std::clog));
                                        std::clog << "pair2:" << std::endl;
-                                       (*it).rest.print(print_tree(std::clog));
-                                       (*it).coeff.print(print_tree(std::clog));
+                                       it->rest.print(print_tree(std::clog));
+                                       it->coeff.print(print_tree(std::clog));
                                        return 0;
                                }
                        }
@@ -1516,11 +1468,11 @@ bool expairseq::is_canonical() const
  *  if no members were changed. */
 epvector * expairseq::expandchildren(unsigned options) const
 {
-       epvector::const_iterator last = seq.end();
+       const epvector::const_iterator last = seq.end();
        epvector::const_iterator cit = seq.begin();
        while (cit!=last) {
-               const ex &expanded_ex = (*cit).rest.expand(options);
-               if (!are_ex_trivially_equal((*cit).rest,expanded_ex)) {
+               const ex &expanded_ex = cit->rest.expand(options);
+               if (!are_ex_trivially_equal(cit->rest,expanded_ex)) {
                        
                        // something changed, copy seq, eval and return it
                        epvector *s = new epvector;
@@ -1534,12 +1486,12 @@ epvector * expairseq::expandchildren(unsigned options) const
                        }
                        // copy first changed element
                        s->push_back(combine_ex_with_coeff_to_pair(expanded_ex,
-                                                                  (*cit2).coeff));
+                                                                  cit2->coeff));
                        ++cit2;
                        // copy rest
                        while (cit2!=last) {
-                               s->push_back(combine_ex_with_coeff_to_pair((*cit2).rest.expand(options),
-                                                                          (*cit2).coeff));
+                               s->push_back(combine_ex_with_coeff_to_pair(cit2->rest.expand(options),
+                                                                          cit2->coeff));
                                ++cit2;
                        }
                        return s;
@@ -1569,11 +1521,11 @@ epvector * expairseq::evalchildren(int level) const
                throw(std::runtime_error("max recursion level reached"));
        
        --level;
-       epvector::const_iterator last=seq.end();
-       epvector::const_iterator cit=seq.begin();
+       epvector::const_iterator last = seq.end();
+       epvector::const_iterator cit = seq.begin();
        while (cit!=last) {
-               const ex &evaled_ex = (*cit).rest.eval(level);
-               if (!are_ex_trivially_equal((*cit).rest,evaled_ex)) {
+               const ex &evaled_ex = cit->rest.eval(level);
+               if (!are_ex_trivially_equal(cit->rest,evaled_ex)) {
                        
                        // something changed, copy seq, eval and return it
                        epvector *s = new epvector;
@@ -1587,12 +1539,12 @@ epvector * expairseq::evalchildren(int level) const
                        }
                        // copy first changed element
                        s->push_back(combine_ex_with_coeff_to_pair(evaled_ex,
-                                                                  (*cit2).coeff));
+                                                                  cit2->coeff));
                        ++cit2;
                        // copy rest
                        while (cit2!=last) {
-                               s->push_back(combine_ex_with_coeff_to_pair((*cit2).rest.eval(level),
-                                                                          (*cit2).coeff));
+                               s->push_back(combine_ex_with_coeff_to_pair(cit2->rest.eval(level),
+                                                                          cit2->coeff));
                                ++cit2;
                        }
                        return s;
@@ -1604,71 +1556,6 @@ epvector * expairseq::evalchildren(int level) const
 }
 
 
-/** Member-wise evaluate numerically all expairs in this sequence.
- *
- *  @see expairseq::evalf()
- *  @return epvector with all entries evaluated numerically. */
-epvector expairseq::evalfchildren(int level) const
-{
-       if (level==1)
-               return seq;
-       
-       if (level==-max_recursion_level)
-               throw(std::runtime_error("max recursion level reached"));
-       
-       epvector s;
-       s.reserve(seq.size());
-       
-       --level;
-       for (epvector::const_iterator it=seq.begin(); it!=seq.end(); ++it) {
-               s.push_back(combine_ex_with_coeff_to_pair((*it).rest.evalf(level),
-                                                         (*it).coeff.evalf(level)));
-       }
-       return s;
-}
-
-
-/** Member-wise normalize all expairs in this sequence.
- *
- *  @see expairseq::normal()
- *  @return epvector with all entries normalized. */
-epvector expairseq::normalchildren(int level) const
-{
-       if (level==1)
-               return seq;
-       
-       if (level==-max_recursion_level)
-               throw(std::runtime_error("max recursion level reached"));
-       
-       epvector s;
-       s.reserve(seq.size());
-       
-       --level;
-       for (epvector::const_iterator it=seq.begin(); it!=seq.end(); ++it) {
-               s.push_back(combine_ex_with_coeff_to_pair((*it).rest.normal(level),
-                                                         (*it).coeff));
-       }
-       return s;
-}
-
-
-/** Member-wise differentiate all expairs in this sequence.
- *
- *  @see expairseq::diff()
- *  @return epvector with all entries differentiated. */
-epvector expairseq::diffchildren(const symbol &y) const
-{
-       epvector s;
-       s.reserve(seq.size());
-       
-       for (epvector::const_iterator it=seq.begin(); it!=seq.end(); ++it) {
-               s.push_back(combine_ex_with_coeff_to_pair((*it).rest.diff(y),
-                                                         (*it).coeff));
-       }
-       return s;
-}
-
-
 /** Member-wise substitute in this sequence.
  *
  *  @see expairseq::subs()
@@ -1682,7 +1569,7 @@ epvector * expairseq::subschildren(const lst &ls, const lst &lr, bool no_pattern
        // is a product or power. In this case we have to recombine the pairs
        // because the numeric coefficients may be part of the search pattern.
        bool complex_subs = false;
-       for (unsigned i=0; i<ls.nops(); i++)
+       for (unsigned i=0; i<ls.nops(); ++i)
                if (is_ex_exactly_of_type(ls.op(i), mul) || is_ex_exactly_of_type(ls.op(i), power)) {
                        complex_subs = true;
                        break;