]> www.ginac.de Git - ginac.git/blobdiff - ginac/mul.cpp
- symbols can have a LaTeX name, e.g. symbol s("s", "\\sigma");
[ginac.git] / ginac / mul.cpp
index 97d63f8801ce4ac7f07b3687e0689a9b20ae83c4..75f74b4ba2cb7d06fc1ce969f4072ba7e4494618 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's products of expressions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2001 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
 #include "debugmsg.h"
 #include "utils.h"
 
-#ifndef NO_NAMESPACE_GINAC
 namespace GiNaC {
-#endif // ndef NO_NAMESPACE_GINAC
 
 GINAC_IMPLEMENT_REGISTERED_CLASS(mul, expairseq)
 
 //////////
-// default constructor, destructor, copy constructor assignment operator and helpers
+// default ctor, dctor, copy ctor assignment operator and helpers
 //////////
 
-// public
-
 mul::mul()
 {
-       debugmsg("mul default constructor",LOGLEVEL_CONSTRUCT);
+       debugmsg("mul default ctor",LOGLEVEL_CONSTRUCT);
        tinfo_key = TINFO_mul;
 }
 
-mul::~mul()
-{
-       debugmsg("mul destructor",LOGLEVEL_DESTRUCT);
-       destroy(false);
-}
-
-mul::mul(const mul & other)
-{
-       debugmsg("mul copy constructor",LOGLEVEL_CONSTRUCT);
-       copy(other);
-}
-
-const mul & mul::operator=(const mul & other)
-{
-       debugmsg("mul operator=",LOGLEVEL_ASSIGNMENT);
-       if (this != &other) {
-               destroy(true);
-               copy(other);
-       }
-       return *this;
-}
-
-// protected
-
-void mul::copy(const mul & other)
-{
-       inherited::copy(other);
-}
-
-void mul::destroy(bool call_parent)
-{
-       if (call_parent) inherited::destroy(call_parent);
-}
+DEFAULT_COPY(mul)
+DEFAULT_DESTROY(mul)
 
 //////////
-// other constructors
+// other ctors
 //////////
 
 // public
 
 mul::mul(const ex & lh, const ex & rh)
 {
-       debugmsg("mul constructor from ex,ex",LOGLEVEL_CONSTRUCT);
+       debugmsg("mul ctor from ex,ex",LOGLEVEL_CONSTRUCT);
        tinfo_key = TINFO_mul;
        overall_coeff = _ex1();
        construct_from_2_ex(lh,rh);
@@ -99,7 +64,7 @@ mul::mul(const ex & lh, const ex & rh)
 
 mul::mul(const exvector & v)
 {
-       debugmsg("mul constructor from exvector",LOGLEVEL_CONSTRUCT);
+       debugmsg("mul ctor from exvector",LOGLEVEL_CONSTRUCT);
        tinfo_key = TINFO_mul;
        overall_coeff = _ex1();
        construct_from_exvector(v);
@@ -108,7 +73,7 @@ mul::mul(const exvector & v)
 
 mul::mul(const epvector & v)
 {
-       debugmsg("mul constructor from epvector",LOGLEVEL_CONSTRUCT);
+       debugmsg("mul ctor from epvector",LOGLEVEL_CONSTRUCT);
        tinfo_key = TINFO_mul;
        overall_coeff = _ex1();
        construct_from_epvector(v);
@@ -117,7 +82,7 @@ mul::mul(const epvector & v)
 
 mul::mul(const epvector & v, const ex & oc)
 {
-       debugmsg("mul constructor from epvector,ex",LOGLEVEL_CONSTRUCT);
+       debugmsg("mul ctor from epvector,ex",LOGLEVEL_CONSTRUCT);
        tinfo_key = TINFO_mul;
        overall_coeff = oc;
        construct_from_epvector(v);
@@ -126,7 +91,7 @@ mul::mul(const epvector & v, const ex & oc)
 
 mul::mul(epvector * vp, const ex & oc)
 {
-       debugmsg("mul constructor from epvector *,ex",LOGLEVEL_CONSTRUCT);
+       debugmsg("mul ctor from epvector *,ex",LOGLEVEL_CONSTRUCT);
        tinfo_key = TINFO_mul;
        GINAC_ASSERT(vp!=0);
        overall_coeff = oc;
@@ -137,7 +102,7 @@ mul::mul(epvector * vp, const ex & oc)
 
 mul::mul(const ex & lh, const ex & mh, const ex & rh)
 {
-       debugmsg("mul constructor from ex,ex,ex",LOGLEVEL_CONSTRUCT);
+       debugmsg("mul ctor from ex,ex,ex",LOGLEVEL_CONSTRUCT);
        tinfo_key = TINFO_mul;
        exvector factors;
        factors.reserve(3);
@@ -153,23 +118,7 @@ mul::mul(const ex & lh, const ex & mh, const ex & rh)
 // archiving
 //////////
 
-/** Construct object from archive_node. */
-mul::mul(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
-{
-       debugmsg("mul constructor from archive_node", LOGLEVEL_CONSTRUCT);
-}
-
-/** Unarchive the object. */
-ex mul::unarchive(const archive_node &n, const lst &sym_lst)
-{
-       return (new mul(n, sym_lst))->setflag(status_flags::dynallocated);
-}
-
-/** Archive the object. */
-void mul::archive(archive_node &n) const
-{
-       inherited::archive(n);
-}
+DEFAULT_ARCHIVING(mul)
 
 //////////
 // functions overriding virtual functions from bases classes
@@ -177,105 +126,112 @@ void mul::archive(archive_node &n) const
 
 // public
 
-basic * mul::duplicate() const
+void mul::print(const print_context & c, unsigned level) const
 {
-       debugmsg("mul duplicate",LOGLEVEL_ASSIGNMENT);
-       return new mul(*this);
-}
+       debugmsg("mul print", LOGLEVEL_PRINT);
 
-void mul::print(std::ostream & os, unsigned upper_precedence) const
-{
-       debugmsg("mul print",LOGLEVEL_PRINT);
-       if (precedence<=upper_precedence) os << "(";
-       bool first=true;
-       // first print the overall numeric coefficient:
-       numeric coeff = ex_to_numeric(overall_coeff);
-       if (coeff.csgn()==-1) os << '-';
-       if (!coeff.is_equal(_num1()) &&
-               !coeff.is_equal(_num_1())) {
-               if (coeff.is_rational()) {
-                       if (coeff.is_negative())
-                               os << -coeff;
-                       else
-                               os << coeff;
-               } else {
-                       if (coeff.csgn()==-1)
-                               (-coeff).print(os, precedence);
-                       else
-                               coeff.print(os, precedence);
+       if (is_of_type(c, print_tree)) {
+
+               inherited::print(c, level);
+
+       } else if (is_of_type(c, print_csrc)) {
+
+               c.s << "(";
+
+               if (!overall_coeff.is_equal(_ex1())) {
+                       overall_coeff.bp->print(c, precedence);
+                       c.s << "*";
                }
-               os << '*';
-       }
-       // then proceed with the remaining factors:
-       for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
-               if (!first) {
-                       os << '*';
-               } else {
-                       first=false;
+       
+               // Print arguments, separated by "*" or "/"
+               epvector::const_iterator it = seq.begin(), itend = seq.end();
+               while (it != itend) {
+
+                       // If the first argument is a negative integer power, it gets printed as "1.0/<expr>"
+                       if (it == seq.begin() && ex_to_numeric(it->coeff).is_integer() && it->coeff.compare(_num0()) < 0) {
+                               if (is_of_type(c, print_csrc_cl_N))
+                                       c.s << "recip(";
+                               else
+                                       c.s << "1.0/";
+                       }
+
+                       // If the exponent is 1 or -1, it is left out
+                       if (it->coeff.compare(_ex1()) == 0 || it->coeff.compare(_num_1()) == 0)
+                               it->rest.print(c, precedence);
+                       else {
+                               // Outer parens around ex needed for broken gcc-2.95 parser:
+                               (ex(power(it->rest, abs(ex_to_numeric(it->coeff))))).print(c, level);
+                       }
+
+                       // Separator is "/" for negative integer powers, "*" otherwise
+                       ++it;
+                       if (it != itend) {
+                               if (ex_to_numeric(it->coeff).is_integer() && it->coeff.compare(_num0()) < 0)
+                                       c.s << "/";
+                               else
+                                       c.s << "*";
+                       }
                }
-               recombine_pair_to_ex(*cit).print(os,precedence);
-       }
-       if (precedence<=upper_precedence) os << ")";
-}
 
-void mul::printraw(std::ostream & os) const
-{
-       debugmsg("mul printraw",LOGLEVEL_PRINT);
+               if (precedence <= level)
+                       c.s << ")";
 
-       os << "*(";
-       for (epvector::const_iterator it=seq.begin(); it!=seq.end(); ++it) {
-               os << "(";
-               (*it).rest.bp->printraw(os);
-               os << ",";
-               (*it).coeff.bp->printraw(os);
-               os << "),";
-       }
-       os << ",hash=" << hashvalue << ",flags=" << flags;
-       os << ")";
-}
+       } else {
 
-void mul::printcsrc(std::ostream & os, unsigned type, unsigned upper_precedence) const
-{
-       debugmsg("mul print csrc", LOGLEVEL_PRINT);
-       if (precedence <= upper_precedence)
-               os << "(";
+               if (precedence <= level) {
+                       if (is_of_type(c, print_latex))
+                               c.s << "{(";
+                       else
+                               c.s << "(";
+               }
 
-       if (!overall_coeff.is_equal(_ex1())) {
-               overall_coeff.bp->printcsrc(os,type,precedence);
-               os << "*";
-       }
-       
-       // Print arguments, separated by "*" or "/"
-       epvector::const_iterator it = seq.begin();
-       epvector::const_iterator itend = seq.end();
-       while (it != itend) {
-
-               // If the first argument is a negative integer power, it gets printed as "1.0/<expr>"
-               if (it == seq.begin() && ex_to_numeric(it->coeff).is_integer() && it->coeff.compare(_num0()) < 0) {
-                       if (type == csrc_types::ctype_cl_N)
-                               os << "recip(";
+               bool first = true;
+
+               // First print the overall numeric coefficient
+               numeric coeff = ex_to_numeric(overall_coeff);
+               if (coeff.csgn() == -1)
+                       c.s << '-';
+               if (!coeff.is_equal(_num1()) &&
+                       !coeff.is_equal(_num_1())) {
+                       if (coeff.is_rational()) {
+                               if (coeff.is_negative())
+                                       (-coeff).print(c);
+                               else
+                                       coeff.print(c);
+                       } else {
+                               if (coeff.csgn() == -1)
+                                       (-coeff).print(c, precedence);
+                               else
+                                       coeff.print(c, precedence);
+                       }
+                       if (is_of_type(c, print_latex))
+                               c.s << ' ';
                        else
-                               os << "1.0/";
+                               c.s << '*';
                }
 
-               // If the exponent is 1 or -1, it is left out
-               if (it->coeff.compare(_ex1()) == 0 || it->coeff.compare(_num_1()) == 0)
-                       it->rest.bp->printcsrc(os, type, precedence);
-               else
-                       // outer parens around ex needed for broken gcc-2.95 parser:
-                       (ex(power(it->rest, abs(ex_to_numeric(it->coeff))))).bp->printcsrc(os, type, upper_precedence);
+               // Then proceed with the remaining factors
+               epvector::const_iterator it = seq.begin(), itend = seq.end();
+               while (it != itend) {
+                       if (!first) {
+                               if (is_of_type(c, print_latex))
+                                       c.s << ' ';
+                               else
+                                       c.s << '*';
+                       } else {
+                               first = false;
+                       }
+                       recombine_pair_to_ex(*it).print(c, precedence);
+                       it++;
+               }
 
-               // Separator is "/" for negative integer powers, "*" otherwise
-               ++it;
-               if (it != itend) {
-                       if (ex_to_numeric(it->coeff).is_integer() && it->coeff.compare(_num0()) < 0)
-                               os << "/";
+               if (precedence <= level) {
+                       if (is_of_type(c, print_latex))
+                               c.s << ")}";
                        else
-                               os << "*";
+                               c.s << ")";
                }
        }
-       if (precedence <= upper_precedence)
-               os << ")";
 }
 
 bool mul::info(unsigned inf) const
@@ -304,9 +260,7 @@ bool mul::info(unsigned inf) const
        return inherited::info(inf);
 }
 
-typedef std::vector<int> intvector;
-
-int mul::degree(const symbol & s) const
+int mul::degree(const ex & s) const
 {
        int deg_sum = 0;
        for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
@@ -316,7 +270,7 @@ int mul::degree(const symbol & s) const
        return deg_sum;
 }
 
-int mul::ldegree(const symbol & s) const
+int mul::ldegree(const ex & s) const
 {
        int deg_sum = 0;
        for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
@@ -326,7 +280,7 @@ int mul::ldegree(const symbol & s) const
        return deg_sum;
 }
 
-ex mul::coeff(const symbol & s, int n) const
+ex mul::coeff(const ex & s, int n) const
 {
        exvector coeffseq;
        coeffseq.reserve(seq.size()+1);
@@ -334,7 +288,7 @@ ex mul::coeff(const symbol & s, int n) const
        if (n==0) {
                // product of individual coeffs
                // if a non-zero power of s is found, the resulting product will be 0
-               epvector::const_iterator it=seq.begin();
+               epvector::const_iterator it = seq.begin();
                while (it!=seq.end()) {
                        coeffseq.push_back(recombine_pair_to_ex(*it).coeff(s,n));
                        ++it;
@@ -342,15 +296,15 @@ ex mul::coeff(const symbol & s, int n) const
                coeffseq.push_back(overall_coeff);
                return (new mul(coeffseq))->setflag(status_flags::dynallocated);
        }
-                
+       
        epvector::const_iterator it=seq.begin();
-       bool coeff_found=0;
+       bool coeff_found = 0;
        while (it!=seq.end()) {
-               ex t=recombine_pair_to_ex(*it);
-               ex c=t.coeff(s,n);
+               ex t = recombine_pair_to_ex(*it);
+               ex c = t.coeff(s,n);
                if (!c.is_zero()) {
                        coeffseq.push_back(c);
-                       coeff_found=1;
+                       coeff_found = 1;
                } else {
                        coeffseq.push_back(t);
                }
@@ -370,54 +324,53 @@ ex mul::eval(int level) const
        //                  *(+(x,y,...);c) -> *(+(*(x,c),*(y,c),...)) (c numeric())
        //                  *(x;1) -> x
        //                  *(;c) -> c
-
+       
        debugmsg("mul eval",LOGLEVEL_MEMBER_FUNCTION);
-
-       epvector * evaled_seqp=evalchildren(level);
+       
+       epvector * evaled_seqp = evalchildren(level);
        if (evaled_seqp!=0) {
                // do more evaluation later
                return (new mul(evaled_seqp,overall_coeff))->
-                                  setflag(status_flags::dynallocated);
+                          setflag(status_flags::dynallocated);
        }
-
+       
 #ifdef DO_GINAC_ASSERT
        for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
-               GINAC_ASSERT((!is_ex_exactly_of_type((*cit).rest,mul))||
-                          (!(ex_to_numeric((*cit).coeff).is_integer())));
-               GINAC_ASSERT(!((*cit).is_numeric_with_coeff_1()));
-               if (is_ex_exactly_of_type(recombine_pair_to_ex(*cit),numeric)) {
-                       printtree(cerr,0);
-               }
+               GINAC_ASSERT((!is_ex_exactly_of_type((*cit).rest,mul)) ||
+                            (!(ex_to_numeric((*cit).coeff).is_integer())));
+               GINAC_ASSERT(!(cit->is_canonical_numeric()));
+               if (is_ex_exactly_of_type(recombine_pair_to_ex(*cit),numeric))
+                   print(print_tree(std::cerr));
                GINAC_ASSERT(!is_ex_exactly_of_type(recombine_pair_to_ex(*cit),numeric));
                /* for paranoia */
-               expair p=split_ex_to_pair(recombine_pair_to_ex(*cit));
+               expair p = split_ex_to_pair(recombine_pair_to_ex(*cit));
                GINAC_ASSERT(p.rest.is_equal((*cit).rest));
                GINAC_ASSERT(p.coeff.is_equal((*cit).coeff));
                /* end paranoia */
        }
 #endif // def DO_GINAC_ASSERT
-
+       
        if (flags & status_flags::evaluated) {
                GINAC_ASSERT(seq.size()>0);
-               GINAC_ASSERT((seq.size()>1)||!overall_coeff.is_equal(_ex1()));
+               GINAC_ASSERT(seq.size()>1 || !overall_coeff.is_equal(_ex1()));
                return *this;
        }
-
-       int seq_size=seq.size();
+       
+       int seq_size = seq.size();
        if (overall_coeff.is_equal(_ex0())) {
                // *(...,x;0) -> 0
                return _ex0();
        } else if (seq_size==0) {
                // *(;c) -> c
                return overall_coeff;
-       } else if ((seq_size==1)&&overall_coeff.is_equal(_ex1())) {
+       } else if (seq_size==1 && overall_coeff.is_equal(_ex1())) {
                // *(x;1) -> x
                return recombine_pair_to_ex(*(seq.begin()));
        } else if ((seq_size==1) &&
                   is_ex_exactly_of_type((*seq.begin()).rest,add) &&
                   ex_to_numeric((*seq.begin()).coeff).is_equal(_num1())) {
                // *(+(x,y,...);c) -> +(*(x,c),*(y,c),...) (c numeric(), no powers of +())
-               const add & addref=ex_to_add((*seq.begin()).rest);
+               const add & addref = ex_to_add((*seq.begin()).rest);
                epvector distrseq;
                distrseq.reserve(addref.seq.size());
                for (epvector::const_iterator cit=addref.seq.begin(); cit!=addref.seq.end(); ++cit) {
@@ -450,23 +403,18 @@ ex mul::evalf(int level) const
        return mul(s,overall_coeff.evalf(level));
 }
 
-exvector mul::get_indices(void) const
+ex mul::simplify_ncmul(const exvector & v) const
 {
-       // return union of indices of factors
-       exvector iv;
-       for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
-               exvector subiv=(*cit).rest.get_indices();
-               iv.reserve(iv.size()+subiv.size());
-               for (exvector::const_iterator cit2=subiv.begin(); cit2!=subiv.end(); ++cit2) {
-                       iv.push_back(*cit2);
-               }
+       if (seq.size()==0) {
+               return inherited::simplify_ncmul(v);
        }
-       return iv;
-}
 
-ex mul::simplify_ncmul(const exvector & v) const
-{
-       throw(std::logic_error("mul::simplify_ncmul() should never have been called!"));
+       // Find first noncommutative element and call its simplify_ncmul()
+       for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
+               if (cit->rest.return_type() == return_types::noncommutative)
+                       return cit->rest.simplify_ncmul(v);
+       }
+       return inherited::simplify_ncmul(v);
 }
 
 // protected
@@ -504,11 +452,11 @@ unsigned mul::return_type(void) const
                // mul without factors: should not happen, but commutes
                return return_types::commutative;
        }
-
+       
        bool all_commutative = 1;
        unsigned rt;
        epvector::const_iterator cit_noncommutative_element; // point to first found nc element
-
+       
        for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
                rt=(*cit).rest.return_type();
                if (rt==return_types::noncommutative_composite) return rt; // one ncc -> mul also ncc
@@ -531,15 +479,13 @@ unsigned mul::return_type(void) const
    
 unsigned mul::return_type_tinfo(void) const
 {
-       if (seq.size()==0) {
-               // mul without factors: should not happen
-               return tinfo_key;
-       }
+       if (seq.size()==0)
+               return tinfo_key;  // mul without factors: should not happen
+       
        // return type_info of first noncommutative element
        for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
-               if ((*cit).rest.return_type()==return_types::noncommutative) {
+               if ((*cit).rest.return_type()==return_types::noncommutative)
                        return (*cit).rest.return_type_tinfo();
-               }
        }
        // no noncommutative element found, should not happen
        return tinfo_key;
@@ -558,10 +504,9 @@ ex mul::thisexpairseq(epvector * vp, const ex & oc) const
 expair mul::split_ex_to_pair(const ex & e) const
 {
        if (is_ex_exactly_of_type(e,power)) {
-               const power & powerref=ex_to_power(e);
-               if (is_ex_exactly_of_type(powerref.exponent,numeric)) {
+               const power & powerref = ex_to_power(e);
+               if (is_ex_exactly_of_type(powerref.exponent,numeric))
                        return expair(powerref.basis,powerref.exponent);
-               }
        }
        return expair(e,_ex1());
 }
@@ -605,14 +550,14 @@ bool mul::expair_needs_further_processing(epp it)
        if (is_ex_exactly_of_type((*it).rest,mul) &&
                ex_to_numeric((*it).coeff).is_integer()) {
                // combined pair is product with integer power -> expand it
-               *it=split_ex_to_pair(recombine_pair_to_ex(*it));
+               *it = split_ex_to_pair(recombine_pair_to_ex(*it));
                return true;
        }
        if (is_ex_exactly_of_type((*it).rest,numeric)) {
                expair ep=split_ex_to_pair(recombine_pair_to_ex(*it));
                if (!ep.is_equal(*it)) {
                        // combined pair is a numeric power which can be simplified
-                       *it=ep;
+                       *it = ep;
                        return true;
                }
                if (ex_to_numeric((*it).coeff).is_equal(_num1())) {
@@ -658,7 +603,6 @@ ex mul::expand(unsigned options) const
                return *this;
        
        exvector sub_expanded_seq;
-       intvector positions_of_adds;
        
        epvector * expanded_seqp = expandchildren(options);
        
@@ -667,19 +611,19 @@ ex mul::expand(unsigned options) const
        int number_of_adds = 0;
        epvector non_adds;
        non_adds.reserve(expanded_seq.size());
-       epvector::const_iterator cit=expanded_seq.begin();
+       epvector::const_iterator cit = expanded_seq.begin();
        epvector::const_iterator last = expanded_seq.end();
-       ex last_expanded=_ex1();
+       ex last_expanded = _ex1();
        while (cit!=last) {
                if (is_ex_exactly_of_type((*cit).rest,add) &&
                        ((*cit).coeff.is_equal(_ex1()))) {
                        ++number_of_adds;
                        if (is_ex_exactly_of_type(last_expanded,add)) {
                                // expand adds
-                               add const & add1=ex_to_add(last_expanded);
-                               add const & add2=ex_to_add((*cit).rest);
-                               int n1=add1.nops();
-                               int n2=add2.nops();
+                               const add & add1 = ex_to_add(last_expanded);
+                               const add & add2 = ex_to_add((*cit).rest);
+                               int n1 = add1.nops();
+                               int n2 = add2.nops();
                                exvector distrseq;
                                distrseq.reserve(n1*n2);
                                for (int i1=0; i1<n1; ++i1) {
@@ -687,114 +631,37 @@ ex mul::expand(unsigned options) const
                                                distrseq.push_back(add1.op(i1)*add2.op(i2));
                                        }
                                }
-                               last_expanded=(new add(distrseq))->setflag(status_flags::dynallocated | status_flags::expanded);
+                               last_expanded = (new add(distrseq))->setflag(status_flags::dynallocated | status_flags::expanded);
                        } else {
                                non_adds.push_back(split_ex_to_pair(last_expanded));
-                               last_expanded=(*cit).rest;
+                               last_expanded = (*cit).rest;
                        }
                } else {
                        non_adds.push_back(*cit);
                }
                ++cit;
        }
+       if (expanded_seqp)
+               delete expanded_seqp;
 
        if (is_ex_exactly_of_type(last_expanded,add)) {
-               //ex factors=(new mul(non_adds,overall_coeff))->
-               //             setflag(status_flags::dynallocated | status_flags::expanded);
-               add const & finaladd=ex_to_add(last_expanded);
+               add const & finaladd = ex_to_add(last_expanded);
                exvector distrseq;
-               int n=finaladd.nops();
+               int n = finaladd.nops();
                distrseq.reserve(n);
                for (int i=0; i<n; ++i) {
-                       //distrseq.push_back(factors*finaladd.op(i));
-                       epvector factors=non_adds;
+                       epvector factors = non_adds;
                        factors.push_back(split_ex_to_pair(finaladd.op(i)));
                        distrseq.push_back((new mul(factors,overall_coeff))->setflag(status_flags::dynallocated | status_flags::expanded));
                }
                return ((new add(distrseq))->
-                      setflag(status_flags::dynallocated | status_flags::expanded));
+                       setflag(status_flags::dynallocated | status_flags::expanded));
        }
        non_adds.push_back(split_ex_to_pair(last_expanded));
        return (new mul(non_adds,overall_coeff))->
-              setflag(status_flags::dynallocated | status_flags::expanded);
+               setflag(status_flags::dynallocated | status_flags::expanded);
 }
 
-/*
-ex mul::expand(unsigned options) const
-{
-       if (flags & status_flags::expanded)
-               return *this;
-       
-       exvector sub_expanded_seq;
-       intvector positions_of_adds;
-       intvector number_of_add_operands;
-       
-       epvector * expanded_seqp = expandchildren(options);
-       
-       const epvector & expanded_seq = expanded_seqp==0 ? seq : *expanded_seqp;
-       
-       positions_of_adds.resize(expanded_seq.size());
-       number_of_add_operands.resize(expanded_seq.size());
-       
-       int number_of_adds = 0;
-       int number_of_expanded_terms = 1;
-       
-       unsigned current_position = 0;
-       epvector::const_iterator last = expanded_seq.end();
-       for (epvector::const_iterator cit = expanded_seq.begin(); cit!=last; ++cit) {
-               if (is_ex_exactly_of_type((*cit).rest,add) &&
-                       ((*cit).coeff.is_equal(_ex1()))) {
-                       positions_of_adds[number_of_adds] = current_position;
-                       const add & expanded_addref = ex_to_add((*cit).rest);
-                       unsigned addref_nops = expanded_addref.nops();
-                       number_of_add_operands[number_of_adds] = addref_nops;
-                       number_of_expanded_terms *= addref_nops;
-                       ++number_of_adds;
-               }
-               ++current_position;
-       }
-       
-       if (number_of_adds==0) {
-               if (expanded_seqp==0)
-                       return this->setflag(status_flags::expanded);
-               else
-                       return ((new mul(expanded_seqp,overall_coeff))->
-                              setflag(status_flags::dynallocated | status_flags::expanded));
-       }
-       
-       exvector distrseq;
-       distrseq.reserve(number_of_expanded_terms);
-       
-       intvector k;
-       k.resize(number_of_adds, 0);
-       
-       for (;;) {
-               epvector term;
-               term = expanded_seq;
-               for (int l=0; l<number_of_adds; ++l) {
-                       const add & addref = ex_to_add(expanded_seq[positions_of_adds[l]].rest);
-                       GINAC_ASSERT(term[positions_of_adds[l]].coeff.compare(_ex1())==0);
-                       term[positions_of_adds[l]]=split_ex_to_pair(addref.op(k[l]));
-               }
-               distrseq.push_back((new mul(term,overall_coeff))->
-                                   setflag(status_flags::dynallocated | status_flags::expanded));
-               
-               // increment k[]
-               int l = number_of_adds-1;
-               while ((l>=0) && ((++k[l])>=number_of_add_operands[l])) {
-                       k[l] = 0;    
-                       --l;
-               }
-               if (l < 0) break;
-       }
-       
-       if (expanded_seqp!=0)
-               delete expanded_seqp;
-       
-       return (new add(distrseq))->setflag(status_flags::dynallocated |
-                                                                               status_flags::expanded);
-}
-*/
   
 //////////
 // new virtual functions which can be overridden by derived classes
@@ -806,6 +673,14 @@ ex mul::expand(unsigned options) const
 // non-virtual functions in this class
 //////////
 
+
+/** Member-wise expand the expairs representing this sequence.  This must be
+ *  overridden from expairseq::expandchildren() and done iteratively in order
+ *  to allow for early cancallations and thus safe memory.
+ *
+ *  @see mul::expand()
+ *  @return pointer to epvector containing expanded representation or zero
+ *  pointer, if sequence is unchanged. */
 epvector * mul::expandchildren(unsigned options) const
 {
        epvector::const_iterator last = seq.end();
@@ -816,7 +691,7 @@ epvector * mul::expandchildren(unsigned options) const
                if (!are_ex_trivially_equal(factor,expanded_factor)) {
                        
                        // something changed, copy seq, eval and return it
-                       epvector *s=new epvector;
+                       epvector *s = new epvector;
                        s->reserve(seq.size());
                        
                        // copy parts of seq which are known not to have changed
@@ -840,7 +715,7 @@ epvector * mul::expandchildren(unsigned options) const
        
        return 0; // nothing has changed
 }
-   
+
 //////////
 // static member variables
 //////////
@@ -849,14 +724,4 @@ epvector * mul::expandchildren(unsigned options) const
 
 unsigned mul::precedence = 50;
 
-
-//////////
-// global constants
-//////////
-
-const mul some_mul;
-const std::type_info & typeid_mul = typeid(some_mul);
-
-#ifndef NO_NAMESPACE_GINAC
 } // namespace GiNaC
-#endif // ndef NO_NAMESPACE_GINAC