]> www.ginac.de Git - ginac.git/blobdiff - ginac/add.cpp
[bugfix] Make sure add::eval() collects all numeric terms *correctly*.
[ginac.git] / ginac / add.cpp
index 9edbf13947304b8f26756e06f3119522ccd926c1..1a19d86d863b79cdf7fd8977ed37ff04cbefbce0 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's sums of expressions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2003 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
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include <iostream>
-#include <stdexcept>
-
 #include "add.h"
 #include "mul.h"
-#include "matrix.h"
 #include "archive.h"
+#include "operators.h"
+#include "matrix.h"
 #include "utils.h"
+#include "clifford.h"
+#include "ncmul.h"
+#include "compiler.h"
+
+#include <iostream>
+#include <limits>
+#include <stdexcept>
+#include <string>
 
 namespace GiNaC {
 
-GINAC_IMPLEMENT_REGISTERED_CLASS(add, expairseq)
+GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(add, expairseq,
+  print_func<print_context>(&add::do_print).
+  print_func<print_latex>(&add::do_print_latex).
+  print_func<print_csrc>(&add::do_print_csrc).
+  print_func<print_tree>(&add::do_print_tree).
+  print_func<print_python_repr>(&add::do_print_python_repr))
 
 //////////
-// default ctor, dtor, copy ctor, assignment operator and helpers
+// default constructor
 //////////
 
 add::add()
 {
-       tinfo_key = TINFO_add;
 }
 
-DEFAULT_COPY(add)
-DEFAULT_DESTROY(add)
-
 //////////
 // other constructors
 //////////
@@ -53,7 +60,6 @@ DEFAULT_DESTROY(add)
 
 add::add(const ex & lh, const ex & rh)
 {
-       tinfo_key = TINFO_add;
        overall_coeff = _ex0;
        construct_from_2_ex(lh,rh);
        GINAC_ASSERT(is_canonical());
@@ -61,7 +67,6 @@ add::add(const ex & lh, const ex & rh)
 
 add::add(const exvector & v)
 {
-       tinfo_key = TINFO_add;
        overall_coeff = _ex0;
        construct_from_exvector(v);
        GINAC_ASSERT(is_canonical());
@@ -69,7 +74,6 @@ add::add(const exvector & v)
 
 add::add(const epvector & v)
 {
-       tinfo_key = TINFO_add;
        overall_coeff = _ex0;
        construct_from_epvector(v);
        GINAC_ASSERT(is_canonical());
@@ -77,19 +81,16 @@ add::add(const epvector & v)
 
 add::add(const epvector & v, const ex & oc)
 {
-       tinfo_key = TINFO_add;
        overall_coeff = oc;
        construct_from_epvector(v);
        GINAC_ASSERT(is_canonical());
 }
 
-add::add(epvector * vp, const ex & oc)
+add::add(std::auto_ptr<epvector> vp, const ex & oc)
 {
-       tinfo_key = TINFO_add;
-       GINAC_ASSERT(vp!=0);
+       GINAC_ASSERT(vp.get()!=0);
        overall_coeff = oc;
        construct_from_epvector(*vp);
-       delete vp;
        GINAC_ASSERT(is_canonical());
 }
 
@@ -97,7 +98,7 @@ add::add(epvector * vp, const ex & oc)
 // archiving
 //////////
 
-DEFAULT_ARCHIVING(add)
+GINAC_BIND_UNARCHIVER(add);
 
 //////////
 // functions overriding virtual functions from base classes
@@ -105,130 +106,116 @@ DEFAULT_ARCHIVING(add)
 
 // public
 
-void add::print(const print_context & c, unsigned level) const
+void add::print_add(const print_context & c, const char *openbrace, const char *closebrace, const char *mul_sym, unsigned level) const
 {
-       if (is_a<print_tree>(c)) {
+       if (precedence() <= level)
+               c.s << openbrace << '(';
 
-               inherited::print(c, level);
+       numeric coeff;
+       bool first = true;
 
-       } else if (is_a<print_csrc>(c)) {
+       // First print the overall numeric coefficient, if present
+       if (!overall_coeff.is_zero()) {
+               overall_coeff.print(c, 0);
+               first = false;
+       }
 
-               if (precedence() <= level)
-                       c.s << "(";
-       
-               // Print arguments, separated by "+"
-               epvector::const_iterator it = seq.begin(), itend = seq.end();
-               while (it != itend) {
-               
-                       // If the coefficient is -1, it is replaced by a single minus sign
-                       if (it->coeff.is_equal(_ex1)) {
-                               it->rest.print(c, precedence());
-                       } else if (it->coeff.is_equal(_ex_1)) {
-                               c.s << "-";
-                               it->rest.print(c, precedence());
-                       } else if (ex_to<numeric>(it->coeff).numer().is_equal(_num1)) {
-                               it->rest.print(c, precedence());
-                               c.s << "/";
-                               ex_to<numeric>(it->coeff).denom().print(c, precedence());
-                       } else if (ex_to<numeric>(it->coeff).numer().is_equal(_num_1)) {
-                               c.s << "-";
-                               it->rest.print(c, precedence());
-                               c.s << "/";
-                               ex_to<numeric>(it->coeff).denom().print(c, precedence());
+       // Then proceed with the remaining factors
+       epvector::const_iterator it = seq.begin(), itend = seq.end();
+       while (it != itend) {
+               coeff = ex_to<numeric>(it->coeff);
+               if (!first) {
+                       if (coeff.csgn() == -1) c.s << '-'; else c.s << '+';
+               } else {
+                       if (coeff.csgn() == -1) c.s << '-';
+                       first = false;
+               }
+               if (!coeff.is_equal(*_num1_p) &&
+                   !coeff.is_equal(*_num_1_p)) {
+                       if (coeff.is_rational()) {
+                               if (coeff.is_negative())
+                                       (-coeff).print(c);
+                               else
+                                       coeff.print(c);
                        } else {
-                               it->coeff.print(c, precedence());
-                               c.s << "*";
-                               it->rest.print(c, precedence());
+                               if (coeff.csgn() == -1)
+                                       (-coeff).print(c, precedence());
+                               else
+                                       coeff.print(c, precedence());
                        }
-               
-                       // Separator is "+", except if the following expression would have a leading minus sign or the sign is sitting in parenthesis (as in a ctor)
-                       ++it;
-                       if (it != itend
-                        && (is_a<print_csrc_cl_N>(c) || !it->coeff.info(info_flags::real)  // sign inside ctor arguments
-                         || !(it->coeff.info(info_flags::negative) || (it->coeff.is_equal(_num1) && is_exactly_a<numeric>(it->rest) && it->rest.info(info_flags::negative)))))
-                               c.s << "+";
-               }
-       
-               if (!overall_coeff.is_zero()) {
-                       if (overall_coeff.info(info_flags::positive)
-                        || is_a<print_csrc_cl_N>(c) || !overall_coeff.info(info_flags::real))  // sign inside ctor argument
-                               c.s << '+';
-                       overall_coeff.print(c, precedence());
-               }
-               
-               if (precedence() <= level)
-                       c.s << ")";
-
-       } else if (is_a<print_python_repr>(c)) {
-
-               c.s << class_name() << '(';
-               op(0).print(c);
-               for (unsigned i=1; i<nops(); ++i) {
-                       c.s << ',';
-                       op(i).print(c);
+                       c.s << mul_sym;
                }
-               c.s << ')';
-
-       } else {
+               it->rest.print(c, precedence());
+               ++it;
+       }
 
-               if (precedence() <= level) {
-                       if (is_a<print_latex>(c))
-                               c.s << "{(";
-                       else
-                               c.s << "(";
-               }
+       if (precedence() <= level)
+               c.s << ')' << closebrace;
+}
 
-               numeric coeff;
-               bool first = true;
+void add::do_print(const print_context & c, unsigned level) const
+{
+       print_add(c, "", "", "*", level);
+}
 
-               // First print the overall numeric coefficient, if present
-               if (!overall_coeff.is_zero()) {
-                       if (!is_a<print_tree>(c))
-                               overall_coeff.print(c, 0);
-                       else
-                               overall_coeff.print(c, precedence());
-                       first = false;
-               }
+void add::do_print_latex(const print_latex & c, unsigned level) const
+{
+       print_add(c, "{", "}", " ", level);
+}
 
-               // Then proceed with the remaining factors
-               epvector::const_iterator it = seq.begin(), itend = seq.end();
-               while (it != itend) {
-                       coeff = ex_to<numeric>(it->coeff);
-                       if (!first) {
-                               if (coeff.csgn() == -1) c.s << '-'; else c.s << '+';
-                       } else {
-                               if (coeff.csgn() == -1) c.s << '-';
-                               first = false;
-                       }
-                       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_a<print_latex>(c))
-                                       c.s << ' ';
-                               else
-                                       c.s << '*';
-                       }
+void add::do_print_csrc(const print_csrc & c, unsigned level) const
+{
+       if (precedence() <= level)
+               c.s << "(";
+       
+       // Print arguments, separated by "+" or "-"
+       epvector::const_iterator it = seq.begin(), itend = seq.end();
+       char separator = ' ';
+       while (it != itend) {
+               
+               // If the coefficient is negative, separator is "-"
+               if (it->coeff.is_equal(_ex_1) || 
+                       ex_to<numeric>(it->coeff).numer().is_equal(*_num_1_p))
+                       separator = '-';
+               c.s << separator;
+               if (it->coeff.is_equal(_ex1) || it->coeff.is_equal(_ex_1)) {
+                       it->rest.print(c, precedence());
+               } else if (ex_to<numeric>(it->coeff).numer().is_equal(*_num1_p) ||
+                                ex_to<numeric>(it->coeff).numer().is_equal(*_num_1_p))
+               {
+                       it->rest.print(c, precedence());
+                       c.s << '/';
+                       ex_to<numeric>(it->coeff).denom().print(c, precedence());
+               } else {
+                       it->coeff.print(c, precedence());
+                       c.s << '*';
                        it->rest.print(c, precedence());
-                       ++it;
                }
+               
+               ++it;
+               separator = '+';
+       }
+       
+       if (!overall_coeff.is_zero()) {
+               if (overall_coeff.info(info_flags::positive)
+                || is_a<print_csrc_cl_N>(c) || !overall_coeff.info(info_flags::real))  // sign inside ctor argument
+                       c.s << '+';
+               overall_coeff.print(c, precedence());
+       }
+               
+       if (precedence() <= level)
+               c.s << ")";
+}
 
-               if (precedence() <= level) {
-                       if (is_a<print_latex>(c))
-                               c.s << ")}";
-                       else
-                               c.s << ")";
-               }
+void add::do_print_python_repr(const print_python_repr & c, unsigned level) const
+{
+       c.s << class_name() << '(';
+       op(0).print(c);
+       for (size_t i=1; i<nops(); ++i) {
+               c.s << ',';
+               op(i).print(c);
        }
+       c.s << ')';
 }
 
 bool add::info(unsigned inf) const
@@ -238,6 +225,16 @@ bool add::info(unsigned inf) const
                case info_flags::integer_polynomial:
                case info_flags::cinteger_polynomial:
                case info_flags::rational_polynomial:
+               case info_flags::real:
+               case info_flags::rational:
+               case info_flags::integer:
+               case info_flags::crational:
+               case info_flags::cinteger:
+               case info_flags::positive:
+               case info_flags::nonnegative:
+               case info_flags::posint:
+               case info_flags::nonnegint:
+               case info_flags::even:
                case info_flags::crational_polynomial:
                case info_flags::rational_function: {
                        epvector::const_iterator i = seq.begin(), end = seq.end();
@@ -246,6 +243,8 @@ bool add::info(unsigned inf) const
                                        return false;
                                ++i;
                        }
+                       if (overall_coeff.is_zero() && (inf == info_flags::positive || inf == info_flags::posint))
+                               return true;
                        return overall_coeff.info(inf);
                }
                case info_flags::algebraic: {
@@ -261,9 +260,19 @@ bool add::info(unsigned inf) const
        return inherited::info(inf);
 }
 
+bool add::is_polynomial(const ex & var) const
+{
+       for (epvector::const_iterator i=seq.begin(); i!=seq.end(); ++i) {
+               if (!(i->rest).is_polynomial(var)) {
+                       return false;
+               }
+       }
+       return true;
+}
+
 int add::degree(const ex & s) const
 {
-       int deg = INT_MIN;
+       int deg = std::numeric_limits<int>::min();
        if (!overall_coeff.is_zero())
                deg = 0;
        
@@ -280,7 +289,7 @@ int add::degree(const ex & s) const
 
 int add::ldegree(const ex & s) const
 {
-       int deg = INT_MAX;
+       int deg = std::numeric_limits<int>::max();
        if (!overall_coeff.is_zero())
                deg = 0;
        
@@ -297,18 +306,32 @@ int add::ldegree(const ex & s) const
 
 ex add::coeff(const ex & s, int n) const
 {
-       epvector *coeffseq = new epvector();
+       std::auto_ptr<epvector> coeffseq(new epvector);
+       std::auto_ptr<epvector> coeffseq_cliff(new epvector);
+       int rl = clifford_max_label(s);
+       bool do_clifford = (rl != -1);
+       bool nonscalar = false;
 
        // Calculate sum of coefficients in each term
        epvector::const_iterator i = seq.begin(), end = seq.end();
        while (i != end) {
                ex restcoeff = i->rest.coeff(s, n);
-               if (!restcoeff.is_zero())
+               if (!restcoeff.is_zero()) {
+                       if (do_clifford) {
+                               if (clifford_max_label(restcoeff) == -1) {
+                                       coeffseq_cliff->push_back(combine_ex_with_coeff_to_pair(ncmul(restcoeff, dirac_ONE(rl)), i->coeff));
+                               } else {
+                                       coeffseq_cliff->push_back(combine_ex_with_coeff_to_pair(restcoeff, i->coeff));
+                                       nonscalar = true;
+                               }
+                       }
                        coeffseq->push_back(combine_ex_with_coeff_to_pair(restcoeff, i->coeff));
+               }
                ++i;
        }
 
-       return (new add(coeffseq, n==0 ? overall_coeff : _ex0))->setflag(status_flags::dynallocated);
+       return (new add(nonscalar ? coeffseq_cliff : coeffseq,
+                       n==0 ? overall_coeff : _ex0))->setflag(status_flags::dynallocated);
 }
 
 /** Perform automatic term rewriting rules in this class.  In the following
@@ -320,8 +343,8 @@ ex add::coeff(const ex & s, int n) const
  *  @param level cut-off in recursive evaluation */
 ex add::eval(int level) const
 {
-       epvector *evaled_seqp = evalchildren(level);
-       if (evaled_seqp) {
+       std::auto_ptr<epvector> evaled_seqp = evalchildren(level);
+       if (unlikely(evaled_seqp.get() != 0)) {
                // do more evaluation later
                return (new add(evaled_seqp, overall_coeff))->
                       setflag(status_flags::dynallocated);
@@ -331,9 +354,6 @@ ex add::eval(int level) const
        epvector::const_iterator i = seq.begin(), end = seq.end();
        while (i != end) {
                GINAC_ASSERT(!is_exactly_a<add>(i->rest));
-               if (is_ex_exactly_of_type(i->rest,numeric))
-                       dbgprint();
-               GINAC_ASSERT(!is_exactly_a<numeric>(i->rest));
                ++i;
        }
 #endif // def DO_GINAC_ASSERT
@@ -354,14 +374,41 @@ ex add::eval(int level) const
        } else if (!overall_coeff.is_zero() && seq[0].rest.return_type() != return_types::commutative) {
                throw (std::logic_error("add::eval(): sum of non-commutative objects has non-zero numeric term"));
        }
+       
+       // if any terms in the sum still are purely numeric, then they are more
+       // appropriately collected into the overall coefficient
+       epvector::const_iterator last = seq.end();
+       epvector::const_iterator j = seq.begin();
+       int terms_to_collect = 0;
+       while (j != last) {
+               if (unlikely(is_a<numeric>(j->rest)))
+                       ++terms_to_collect;
+               ++j;
+       }
+       if (terms_to_collect) {
+               std::auto_ptr<epvector> s(new epvector);
+               s->reserve(seq_size - terms_to_collect);
+               numeric oc = *_num0_p;
+               j = seq.begin();
+               while (j != last) {
+                       if (unlikely(is_a<numeric>(j->rest)))
+                               oc = oc.add(ex_to<numeric>(j->rest).mul(ex_to<numeric>(j->coeff)));
+                       else
+                               s->push_back(*j);
+                       ++j;
+               }
+               return (new add(s, ex_to<numeric>(overall_coeff).add_dyn(oc)))
+                       ->setflag(status_flags::dynallocated);
+       }
+       
        return this->hold();
 }
 
-ex add::evalm(void) const
+ex add::evalm() const
 {
        // Evaluate children first and add up all matrices. Stop if there's one
        // term that is not a matrix.
-       epvector *s = new epvector;
+       std::auto_ptr<epvector> s(new epvector);
        s->reserve(seq.size());
 
        bool all_matrices = true;
@@ -372,7 +419,7 @@ ex add::evalm(void) const
        while (it != itend) {
                const ex &m = recombine_pair_to_ex(*it).evalm();
                s->push_back(split_ex_to_pair(m));
-               if (is_ex_of_type(m, matrix)) {
+               if (is_a<matrix>(m)) {
                        if (first_term) {
                                sum = ex_to<matrix>(m);
                                first_term = false;
@@ -383,19 +430,80 @@ ex add::evalm(void) const
                ++it;
        }
 
-       if (all_matrices) {
-               delete s;
+       if (all_matrices)
                return sum + overall_coeff;
-       else
+       else
                return (new add(s, overall_coeff))->setflag(status_flags::dynallocated);
 }
 
-ex add::simplify_ncmul(const exvector & v) const
+ex add::conjugate() const
+{
+       exvector *v = 0;
+       for (size_t i=0; i<nops(); ++i) {
+               if (v) {
+                       v->push_back(op(i).conjugate());
+                       continue;
+               }
+               ex term = op(i);
+               ex ccterm = term.conjugate();
+               if (are_ex_trivially_equal(term, ccterm))
+                       continue;
+               v = new exvector;
+               v->reserve(nops());
+               for (size_t j=0; j<i; ++j)
+                       v->push_back(op(j));
+               v->push_back(ccterm);
+       }
+       if (v) {
+               ex result = add(*v);
+               delete v;
+               return result;
+       }
+       return *this;
+}
+
+ex add::real_part() const
+{
+       epvector v;
+       v.reserve(seq.size());
+       for (epvector::const_iterator i=seq.begin(); i!=seq.end(); ++i)
+               if ((i->coeff).info(info_flags::real)) {
+                       ex rp = (i->rest).real_part();
+                       if (!rp.is_zero())
+                               v.push_back(expair(rp, i->coeff));
+               } else {
+                       ex rp=recombine_pair_to_ex(*i).real_part();
+                       if (!rp.is_zero())
+                               v.push_back(split_ex_to_pair(rp));
+               }
+       return (new add(v, overall_coeff.real_part()))
+               -> setflag(status_flags::dynallocated);
+}
+
+ex add::imag_part() const
+{
+       epvector v;
+       v.reserve(seq.size());
+       for (epvector::const_iterator i=seq.begin(); i!=seq.end(); ++i)
+               if ((i->coeff).info(info_flags::real)) {
+                       ex ip = (i->rest).imag_part();
+                       if (!ip.is_zero())
+                               v.push_back(expair(ip, i->coeff));
+               } else {
+                       ex ip=recombine_pair_to_ex(*i).imag_part();
+                       if (!ip.is_zero())
+                               v.push_back(split_ex_to_pair(ip));
+               }
+       return (new add(v, overall_coeff.imag_part()))
+               -> setflag(status_flags::dynallocated);
+}
+
+ex add::eval_ncmul(const exvector & v) const
 {
        if (seq.empty())
-               return inherited::simplify_ncmul(v);
+               return inherited::eval_ncmul(v);
        else
-               return seq.begin()->rest.simplify_ncmul(v);
+               return seq.begin()->rest.eval_ncmul(v);
 }    
 
 // protected
@@ -404,7 +512,7 @@ ex add::simplify_ncmul(const exvector & v) const
  *  @see ex::diff */
 ex add::derivative(const symbol & y) const
 {
-       epvector *s = new epvector();
+       std::auto_ptr<epvector> s(new epvector);
        s->reserve(seq.size());
        
        // Only differentiate the "rest" parts of the expairs. This is faster
@@ -423,42 +531,41 @@ int add::compare_same_type(const basic & other) const
        return inherited::compare_same_type(other);
 }
 
-bool add::is_equal_same_type(const basic & other) const
-{
-       return inherited::is_equal_same_type(other);
-}
-
-unsigned add::return_type(void) const
+unsigned add::return_type() const
 {
        if (seq.empty())
                return return_types::commutative;
        else
                return seq.begin()->rest.return_type();
 }
-   
-unsigned add::return_type_tinfo(void) const
+
+return_type_t add::return_type_tinfo() const
 {
        if (seq.empty())
-               return tinfo_key;
+               return make_return_type_t<add>();
        else
                return seq.begin()->rest.return_type_tinfo();
 }
 
-ex add::thisexpairseq(const epvector & v, const ex & oc) const
+// Note: do_index_renaming is ignored because it makes no sense for an add.
+ex add::thisexpairseq(const epvector & v, const ex & oc, bool do_index_renaming) const
 {
        return (new add(v,oc))->setflag(status_flags::dynallocated);
 }
 
-ex add::thisexpairseq(epvector * vp, const ex & oc) const
+// Note: do_index_renaming is ignored because it makes no sense for an add.
+ex add::thisexpairseq(std::auto_ptr<epvector> vp, const ex & oc, bool do_index_renaming) const
 {
        return (new add(vp,oc))->setflag(status_flags::dynallocated);
 }
 
 expair add::split_ex_to_pair(const ex & e) const
 {
-       if (is_ex_exactly_of_type(e,mul)) {
+       if (is_exactly_a<mul>(e)) {
                const mul &mulref(ex_to<mul>(e));
                const ex &numfactor = mulref.overall_coeff;
+               if (numfactor.is_equal(_ex1))
+                       return expair(e, _ex1);
                mul *mulcopyp = new mul(mulref);
                mulcopyp->overall_coeff = _ex1;
                mulcopyp->clearflag(status_flags::evaluated);
@@ -470,48 +577,50 @@ expair add::split_ex_to_pair(const ex & e) const
 }
 
 expair add::combine_ex_with_coeff_to_pair(const ex & e,
-                                                                                 const ex & c) const
+                                          const ex & c) const
 {
        GINAC_ASSERT(is_exactly_a<numeric>(c));
-       if (is_ex_exactly_of_type(e, mul)) {
+       if (is_exactly_a<mul>(e)) {
                const mul &mulref(ex_to<mul>(e));
                const ex &numfactor = mulref.overall_coeff;
+               if (numfactor.is_equal(_ex1))
+                       return expair(e, c);
                mul *mulcopyp = new mul(mulref);
                mulcopyp->overall_coeff = _ex1;
                mulcopyp->clearflag(status_flags::evaluated);
                mulcopyp->clearflag(status_flags::hash_calculated);
                mulcopyp->setflag(status_flags::dynallocated);
-               if (are_ex_trivially_equal(c, _ex1))
+               if (c.is_equal(_ex1))
                        return expair(*mulcopyp, numfactor);
-               else if (are_ex_trivially_equal(numfactor, _ex1))
-                       return expair(*mulcopyp, c);
                else
                        return expair(*mulcopyp, ex_to<numeric>(numfactor).mul_dyn(ex_to<numeric>(c)));
-       } else if (is_ex_exactly_of_type(e, numeric)) {
-               if (are_ex_trivially_equal(c, _ex1))
+       } else if (is_exactly_a<numeric>(e)) {
+               if (c.is_equal(_ex1))
                        return expair(e, _ex1);
+               if (e.is_equal(_ex1))
+                       return expair(c, _ex1);
                return expair(ex_to<numeric>(e).mul_dyn(ex_to<numeric>(c)), _ex1);
        }
        return expair(e, c);
 }
 
 expair add::combine_pair_with_coeff_to_pair(const expair & p,
-                                                                                       const ex & c) const
+                                            const ex & c) const
 {
        GINAC_ASSERT(is_exactly_a<numeric>(p.coeff));
        GINAC_ASSERT(is_exactly_a<numeric>(c));
 
-       if (is_ex_exactly_of_type(p.rest,numeric)) {
-               GINAC_ASSERT(ex_to<numeric>(p.coeff).is_equal(_num1)); // should be normalized
+       if (is_exactly_a<numeric>(p.rest)) {
+               GINAC_ASSERT(ex_to<numeric>(p.coeff).is_equal(*_num1_p)); // should be normalized
                return expair(ex_to<numeric>(p.rest).mul_dyn(ex_to<numeric>(c)),_ex1);
        }
 
        return expair(p.rest,ex_to<numeric>(p.coeff).mul_dyn(ex_to<numeric>(c)));
 }
-       
+
 ex add::recombine_pair_to_ex(const expair & p) const
 {
-       if (ex_to<numeric>(p.coeff).is_equal(_num1))
+       if (ex_to<numeric>(p.coeff).is_equal(*_num1_p))
                return p.rest;
        else
                return (new mul(p.rest,p.coeff))->setflag(status_flags::dynallocated);
@@ -519,8 +628,8 @@ ex add::recombine_pair_to_ex(const expair & p) const
 
 ex add::expand(unsigned options) const
 {
-       epvector *vp = expandchildren(options);
-       if (vp == NULL) {
+       std::auto_ptr<epvector> vp = expandchildren(options);
+       if (vp.get() == 0) {
                // the terms have not changed, so it is safe to declare this expanded
                return (options == 0) ? setflag(status_flags::expanded) : *this;
        }