]> www.ginac.de Git - ginac.git/blobdiff - ginac/inifcns_trans.cpp
[PATCH 1/3] Automatic evaluation of (e^t)^s = e^(ts).
[ginac.git] / ginac / inifcns_trans.cpp
index c12df144c8bcedeb534318f57bba695b2a053520..f6550f6d734ba7e4dfa1798d6de3cee6595e05fb 100644 (file)
@@ -4,7 +4,7 @@
  *  functions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2004 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2020 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 <vector>
-#include <stdexcept>
-
 #include "inifcns.h"
 #include "ex.h"
 #include "constant.h"
+#include "add.h"
+#include "mul.h"
 #include "numeric.h"
 #include "power.h"
 #include "operators.h"
@@ -35,6 +34,9 @@
 #include "pseries.h"
 #include "utils.h"
 
+#include <stdexcept>
+#include <vector>
+
 namespace GiNaC {
 
 //////////
@@ -55,30 +57,53 @@ static ex exp_eval(const ex & x)
        if (x.is_zero()) {
                return _ex1;
        }
+
        // exp(n*Pi*I/2) -> {+1|+I|-1|-I}
        const ex TwoExOverPiI=(_ex2*x)/(Pi*I);
        if (TwoExOverPiI.info(info_flags::integer)) {
-               const numeric z = mod(ex_to<numeric>(TwoExOverPiI),_num4);
-               if (z.is_equal(_num0))
+               const numeric z = mod(ex_to<numeric>(TwoExOverPiI),*_num4_p);
+               if (z.is_equal(*_num0_p))
                        return _ex1;
-               if (z.is_equal(_num1))
+               if (z.is_equal(*_num1_p))
                        return ex(I);
-               if (z.is_equal(_num2))
+               if (z.is_equal(*_num2_p))
                        return _ex_1;
-               if (z.is_equal(_num3))
+               if (z.is_equal(*_num3_p))
                        return ex(-I);
        }
+
        // exp(log(x)) -> x
        if (is_ex_the_function(x, log))
                return x.op(0);
        
-       // exp(float)
+       // exp(float) -> float
        if (x.info(info_flags::numeric) && !x.info(info_flags::crational))
                return exp(ex_to<numeric>(x));
        
        return exp(x).hold();
 }
 
+static ex exp_expand(const ex & arg, unsigned options)
+{
+       ex exp_arg;
+       if (options & expand_options::expand_function_args)
+               exp_arg = arg.expand(options);
+       else
+               exp_arg=arg;
+
+       if ((options & expand_options::expand_transcendental)
+               && is_exactly_a<add>(exp_arg)) {
+               exvector prodseq;
+               prodseq.reserve(exp_arg.nops());
+               for (const_iterator i = exp_arg.begin(); i != exp_arg.end(); ++i)
+                       prodseq.push_back(exp(*i));
+
+               return dynallocate<mul>(prodseq).setflag(status_flags::expanded);
+       }
+
+       return exp(exp_arg).hold();
+}
+
 static ex exp_deriv(const ex & x, unsigned deriv_param)
 {
        GINAC_ASSERT(deriv_param==0);
@@ -87,9 +112,48 @@ static ex exp_deriv(const ex & x, unsigned deriv_param)
        return exp(x);
 }
 
+static ex exp_real_part(const ex & x)
+{
+       return exp(GiNaC::real_part(x))*cos(GiNaC::imag_part(x));
+}
+
+static ex exp_imag_part(const ex & x)
+{
+       return exp(GiNaC::real_part(x))*sin(GiNaC::imag_part(x));
+}
+
+static ex exp_conjugate(const ex & x)
+{
+       // conjugate(exp(x))==exp(conjugate(x))
+       return exp(x.conjugate());
+}
+
+static ex exp_power(const ex & x, const ex & a)
+{
+       /*
+        * The power law (e^x)^a=e^(x*a) is used in two cases:
+        * a) a is an integer and x may be complex;
+        * b) both x and a are reals.
+        * Negative a is excluded to keep automatic simplifications like exp(x)/exp(x)=1.
+        */
+       if (a.info(info_flags::nonnegative)
+           && (a.info(info_flags::integer) || (x.info(info_flags::real) && a.info(info_flags::real))))
+               return exp(x*a);
+       else if (a.info(info_flags::negative)
+                && (a.info(info_flags::integer) || (x.info(info_flags::real) && a.info(info_flags::real))))
+               return power(exp(-x*a), _ex_1).hold();
+
+       return power(exp(x), a).hold();
+}
+
 REGISTER_FUNCTION(exp, eval_func(exp_eval).
                        evalf_func(exp_evalf).
+                       expand_func(exp_expand).
                        derivative_func(exp_deriv).
+                       real_part_func(exp_real_part).
+                       imag_part_func(exp_imag_part).
+                       conjugate_func(exp_conjugate).
+                       power_func(exp_power).
                        latex_name("\\exp"));
 
 //////////
@@ -109,31 +173,27 @@ static ex log_eval(const ex & x)
        if (x.info(info_flags::numeric)) {
                if (x.is_zero())         // log(0) -> infinity
                        throw(pole_error("log_eval(): log(0)",0));
-               if (x.info(info_flags::real) && x.info(info_flags::negative))
+               if (x.info(info_flags::rational) && x.info(info_flags::negative))
                        return (log(-x)+I*Pi);
                if (x.is_equal(_ex1))  // log(1) -> 0
                        return _ex0;
                if (x.is_equal(I))       // log(I) -> Pi*I/2
-                       return (Pi*I*_num1_2);
+                       return (Pi*I*_ex1_2);
                if (x.is_equal(-I))      // log(-I) -> -Pi*I/2
-                       return (Pi*I*_num_1_2);
-               // log(float)
+                       return (Pi*I*_ex_1_2);
+
+               // log(float) -> float
                if (!x.info(info_flags::crational))
                        return log(ex_to<numeric>(x));
        }
+
        // log(exp(t)) -> t (if -Pi < t.imag() <= Pi):
        if (is_ex_the_function(x, exp)) {
                const ex &t = x.op(0);
-               if (is_a<symbol>(t) && t.info(info_flags::real)) {
+               if (t.info(info_flags::real))
                        return t;
-               }
-               if (t.info(info_flags::numeric)) {
-                       const numeric &nt = ex_to<numeric>(t);
-                       if (nt.is_real())
-                               return t;
-               }
        }
-       
+
        return log(x).hold();
 }
 
@@ -156,13 +216,17 @@ static ex log_series(const ex &arg,
        // maybe substitution of rel into arg fails because of a pole
        try {
                arg_pt = arg.subs(rel, subs_options::no_pattern);
-       } catch (pole_error) {
+       } catch (pole_error &) {
                must_expand_arg = true;
        }
        // or we are at the branch point anyways
        if (arg_pt.is_zero())
                must_expand_arg = true;
        
+       if (arg.diff(ex_to<symbol>(rel.lhs())).is_zero()) {
+               throw do_taylor();
+       }
+
        if (must_expand_arg) {
                // method:
                // This is the branch point: Series expand the argument first, then
@@ -196,10 +260,20 @@ static ex log_series(const ex &arg,
                if (!argser.is_terminating() || argser.nops()!=1) {
                        // in this case n more (or less) terms are needed
                        // (sadly, to generate them, we have to start from the beginning)
+                       if (n == 0 && coeff == 1) {
+                               ex rest = pseries(rel, epvector{expair(-1, _ex0), expair(Order(_ex1), order)}).add_series(argser);
+                               ex acc = dynallocate<pseries>(rel, epvector());
+                               for (int i = order-1; i>0; --i) {
+                                       epvector cterm { expair(i%2 ? _ex1/i : _ex_1/i, _ex0) };
+                                       acc = pseries(rel, std::move(cterm)).add_series(ex_to<pseries>(acc));
+                                       acc = (ex_to<pseries>(rest)).mul_series(ex_to<pseries>(acc));
+                               }
+                               return acc;
+                       }
                        const ex newarg = ex_to<pseries>((arg/coeff).series(rel, order+n, options)).shift_exponents(-n).convert_to_poly(true);
-                       return pseries(rel, seq).add_series(ex_to<pseries>(log(newarg).series(rel, order, options)));
+                       return pseries(rel, std::move(seq)).add_series(ex_to<pseries>(log(newarg).series(rel, order, options)));
                } else  // it was a monomial
-                       return pseries(rel, seq);
+                       return pseries(rel, std::move(seq));
        }
        if (!(options & series_options::suppress_branchcut) &&
             arg_pt.info(info_flags::negative)) {
@@ -211,17 +285,99 @@ static ex log_series(const ex &arg,
                const symbol foo;
                const ex replarg = series(log(arg), s==foo, order).subs(foo==point, subs_options::no_pattern);
                epvector seq;
-               seq.push_back(expair(-I*csgn(arg*I)*Pi, _ex0));
+               if (order > 0) {
+                       seq.reserve(2);
+                       seq.push_back(expair(-I*csgn(arg*I)*Pi, _ex0));
+               }
                seq.push_back(expair(Order(_ex1), order));
-               return series(replarg - I*Pi + pseries(rel, seq), rel, order);
+               return series(replarg - I*Pi + pseries(rel, std::move(seq)), rel, order);
        }
        throw do_taylor();  // caught by function::series()
 }
 
+static ex log_real_part(const ex & x)
+{
+       if (x.info(info_flags::nonnegative))
+               return log(x).hold();
+       return log(abs(x));
+}
+
+static ex log_imag_part(const ex & x)
+{
+       if (x.info(info_flags::nonnegative))
+               return 0;
+       return atan2(GiNaC::imag_part(x), GiNaC::real_part(x));
+}
+
+static ex log_expand(const ex & arg, unsigned options)
+{
+       if ((options & expand_options::expand_transcendental)
+               && is_exactly_a<mul>(arg) && !arg.info(info_flags::indefinite)) {
+               exvector sumseq;
+               exvector prodseq;
+               sumseq.reserve(arg.nops());
+               prodseq.reserve(arg.nops());
+               bool possign=true;
+
+               // searching for positive/negative factors
+               for (const_iterator i = arg.begin(); i != arg.end(); ++i) {
+                       ex e;
+                       if (options & expand_options::expand_function_args)
+                               e=i->expand(options);
+                       else
+                               e=*i;
+                       if (e.info(info_flags::positive))
+                               sumseq.push_back(log(e));
+                       else if (e.info(info_flags::negative)) {
+                               sumseq.push_back(log(-e));
+                               possign = !possign;
+                       } else
+                               prodseq.push_back(e);
+               }
+
+               if (sumseq.size() > 0) {
+                       ex newarg;
+                       if (options & expand_options::expand_function_args)
+                               newarg=((possign?_ex1:_ex_1)*mul(prodseq)).expand(options);
+                       else {
+                               newarg=(possign?_ex1:_ex_1)*mul(prodseq);
+                               ex_to<basic>(newarg).setflag(status_flags::purely_indefinite);
+                       }
+                       return add(sumseq)+log(newarg);
+               } else {
+                       if (!(options & expand_options::expand_function_args))
+                               ex_to<basic>(arg).setflag(status_flags::purely_indefinite);
+               }
+       }
+
+       if (options & expand_options::expand_function_args)
+               return log(arg.expand(options)).hold();
+       else
+               return log(arg).hold();
+}
+
+static ex log_conjugate(const ex & x)
+{
+       // conjugate(log(x))==log(conjugate(x)) unless on the branch cut which
+       // runs along the negative real axis.
+       if (x.info(info_flags::positive)) {
+               return log(x);
+       }
+       if (is_exactly_a<numeric>(x) &&
+           !x.imag_part().is_zero()) {
+               return log(x.conjugate());
+       }
+       return conjugate_function(log(x)).hold();
+}
+
 REGISTER_FUNCTION(log, eval_func(log_eval).
                        evalf_func(log_evalf).
+                       expand_func(log_expand).
                        derivative_func(log_deriv).
                        series_func(log_series).
+                       real_part_func(log_real_part).
+                       imag_part_func(log_imag_part).
+                       conjugate_func(log_conjugate).
                        latex_name("\\ln"));
 
 //////////
@@ -242,44 +398,47 @@ static ex sin_eval(const ex & x)
        const ex SixtyExOverPi = _ex60*x/Pi;
        ex sign = _ex1;
        if (SixtyExOverPi.info(info_flags::integer)) {
-               numeric z = mod(ex_to<numeric>(SixtyExOverPi),_num120);
-               if (z>=_num60) {
+               numeric z = mod(ex_to<numeric>(SixtyExOverPi),*_num120_p);
+               if (z>=*_num60_p) {
                        // wrap to interval [0, Pi)
-                       z -= _num60;
+                       z -= *_num60_p;
                        sign = _ex_1;
                }
-               if (z>_num30) {
+               if (z>*_num30_p) {
                        // wrap to interval [0, Pi/2)
-                       z = _num60-z;
+                       z = *_num60_p-z;
                }
-               if (z.is_equal(_num0))  // sin(0)       -> 0
+               if (z.is_equal(*_num0_p))  // sin(0)       -> 0
                        return _ex0;
-               if (z.is_equal(_num5))  // sin(Pi/12)   -> sqrt(6)/4*(1-sqrt(3)/3)
+               if (z.is_equal(*_num5_p))  // sin(Pi/12)   -> sqrt(6)/4*(1-sqrt(3)/3)
                        return sign*_ex1_4*sqrt(_ex6)*(_ex1+_ex_1_3*sqrt(_ex3));
-               if (z.is_equal(_num6))  // sin(Pi/10)   -> sqrt(5)/4-1/4
+               if (z.is_equal(*_num6_p))  // sin(Pi/10)   -> sqrt(5)/4-1/4
                        return sign*(_ex1_4*sqrt(_ex5)+_ex_1_4);
-               if (z.is_equal(_num10)) // sin(Pi/6)    -> 1/2
+               if (z.is_equal(*_num10_p)) // sin(Pi/6)    -> 1/2
                        return sign*_ex1_2;
-               if (z.is_equal(_num15)) // sin(Pi/4)    -> sqrt(2)/2
+               if (z.is_equal(*_num15_p)) // sin(Pi/4)    -> sqrt(2)/2
                        return sign*_ex1_2*sqrt(_ex2);
-               if (z.is_equal(_num18)) // sin(3/10*Pi) -> sqrt(5)/4+1/4
+               if (z.is_equal(*_num18_p)) // sin(3/10*Pi) -> sqrt(5)/4+1/4
                        return sign*(_ex1_4*sqrt(_ex5)+_ex1_4);
-               if (z.is_equal(_num20)) // sin(Pi/3)    -> sqrt(3)/2
+               if (z.is_equal(*_num20_p)) // sin(Pi/3)    -> sqrt(3)/2
                        return sign*_ex1_2*sqrt(_ex3);
-               if (z.is_equal(_num25)) // sin(5/12*Pi) -> sqrt(6)/4*(1+sqrt(3)/3)
+               if (z.is_equal(*_num25_p)) // sin(5/12*Pi) -> sqrt(6)/4*(1+sqrt(3)/3)
                        return sign*_ex1_4*sqrt(_ex6)*(_ex1+_ex1_3*sqrt(_ex3));
-               if (z.is_equal(_num30)) // sin(Pi/2)    -> 1
+               if (z.is_equal(*_num30_p)) // sin(Pi/2)    -> 1
                        return sign;
        }
-       
+
        if (is_exactly_a<function>(x)) {
                const ex &t = x.op(0);
+
                // sin(asin(x)) -> x
                if (is_ex_the_function(x, asin))
                        return t;
+
                // sin(acos(x)) -> sqrt(1-x^2)
                if (is_ex_the_function(x, acos))
                        return sqrt(_ex1-power(t,_ex2));
+
                // sin(atan(x)) -> x/sqrt(1+x^2)
                if (is_ex_the_function(x, atan))
                        return t*power(_ex1+power(t,_ex2),_ex_1_2);
@@ -288,6 +447,10 @@ static ex sin_eval(const ex & x)
        // sin(float) -> float
        if (x.info(info_flags::numeric) && !x.info(info_flags::crational))
                return sin(ex_to<numeric>(x));
+
+       // sin() is odd
+       if (x.info(info_flags::negative))
+               return -sin(-x);
        
        return sin(x).hold();
 }
@@ -300,9 +463,28 @@ static ex sin_deriv(const ex & x, unsigned deriv_param)
        return cos(x);
 }
 
+static ex sin_real_part(const ex & x)
+{
+       return cosh(GiNaC::imag_part(x))*sin(GiNaC::real_part(x));
+}
+
+static ex sin_imag_part(const ex & x)
+{
+       return sinh(GiNaC::imag_part(x))*cos(GiNaC::real_part(x));
+}
+
+static ex sin_conjugate(const ex & x)
+{
+       // conjugate(sin(x))==sin(conjugate(x))
+       return sin(x.conjugate());
+}
+
 REGISTER_FUNCTION(sin, eval_func(sin_eval).
                        evalf_func(sin_evalf).
                        derivative_func(sin_deriv).
+                       real_part_func(sin_real_part).
+                       imag_part_func(sin_imag_part).
+                       conjugate_func(sin_conjugate).
                        latex_name("\\sin"));
 
 //////////
@@ -323,44 +505,47 @@ static ex cos_eval(const ex & x)
        const ex SixtyExOverPi = _ex60*x/Pi;
        ex sign = _ex1;
        if (SixtyExOverPi.info(info_flags::integer)) {
-               numeric z = mod(ex_to<numeric>(SixtyExOverPi),_num120);
-               if (z>=_num60) {
+               numeric z = mod(ex_to<numeric>(SixtyExOverPi),*_num120_p);
+               if (z>=*_num60_p) {
                        // wrap to interval [0, Pi)
-                       z = _num120-z;
+                       z = *_num120_p-z;
                }
-               if (z>=_num30) {
+               if (z>=*_num30_p) {
                        // wrap to interval [0, Pi/2)
-                       z = _num60-z;
+                       z = *_num60_p-z;
                        sign = _ex_1;
                }
-               if (z.is_equal(_num0))  // cos(0)       -> 1
+               if (z.is_equal(*_num0_p))  // cos(0)       -> 1
                        return sign;
-               if (z.is_equal(_num5))  // cos(Pi/12)   -> sqrt(6)/4*(1+sqrt(3)/3)
+               if (z.is_equal(*_num5_p))  // cos(Pi/12)   -> sqrt(6)/4*(1+sqrt(3)/3)
                        return sign*_ex1_4*sqrt(_ex6)*(_ex1+_ex1_3*sqrt(_ex3));
-               if (z.is_equal(_num10)) // cos(Pi/6)    -> sqrt(3)/2
+               if (z.is_equal(*_num10_p)) // cos(Pi/6)    -> sqrt(3)/2
                        return sign*_ex1_2*sqrt(_ex3);
-               if (z.is_equal(_num12)) // cos(Pi/5)    -> sqrt(5)/4+1/4
+               if (z.is_equal(*_num12_p)) // cos(Pi/5)    -> sqrt(5)/4+1/4
                        return sign*(_ex1_4*sqrt(_ex5)+_ex1_4);
-               if (z.is_equal(_num15)) // cos(Pi/4)    -> sqrt(2)/2
+               if (z.is_equal(*_num15_p)) // cos(Pi/4)    -> sqrt(2)/2
                        return sign*_ex1_2*sqrt(_ex2);
-               if (z.is_equal(_num20)) // cos(Pi/3)    -> 1/2
+               if (z.is_equal(*_num20_p)) // cos(Pi/3)    -> 1/2
                        return sign*_ex1_2;
-               if (z.is_equal(_num24)) // cos(2/5*Pi)  -> sqrt(5)/4-1/4x
+               if (z.is_equal(*_num24_p)) // cos(2/5*Pi)  -> sqrt(5)/4-1/4x
                        return sign*(_ex1_4*sqrt(_ex5)+_ex_1_4);
-               if (z.is_equal(_num25)) // cos(5/12*Pi) -> sqrt(6)/4*(1-sqrt(3)/3)
+               if (z.is_equal(*_num25_p)) // cos(5/12*Pi) -> sqrt(6)/4*(1-sqrt(3)/3)
                        return sign*_ex1_4*sqrt(_ex6)*(_ex1+_ex_1_3*sqrt(_ex3));
-               if (z.is_equal(_num30)) // cos(Pi/2)    -> 0
+               if (z.is_equal(*_num30_p)) // cos(Pi/2)    -> 0
                        return _ex0;
        }
-       
+
        if (is_exactly_a<function>(x)) {
                const ex &t = x.op(0);
+
                // cos(acos(x)) -> x
                if (is_ex_the_function(x, acos))
                        return t;
+
                // cos(asin(x)) -> sqrt(1-x^2)
                if (is_ex_the_function(x, asin))
                        return sqrt(_ex1-power(t,_ex2));
+
                // cos(atan(x)) -> 1/sqrt(1+x^2)
                if (is_ex_the_function(x, atan))
                        return power(_ex1+power(t,_ex2),_ex_1_2);
@@ -370,6 +555,10 @@ static ex cos_eval(const ex & x)
        if (x.info(info_flags::numeric) && !x.info(info_flags::crational))
                return cos(ex_to<numeric>(x));
        
+       // cos() is even
+       if (x.info(info_flags::negative))
+               return cos(-x);
+       
        return cos(x).hold();
 }
 
@@ -381,9 +570,28 @@ static ex cos_deriv(const ex & x, unsigned deriv_param)
        return -sin(x);
 }
 
+static ex cos_real_part(const ex & x)
+{
+       return cosh(GiNaC::imag_part(x))*cos(GiNaC::real_part(x));
+}
+
+static ex cos_imag_part(const ex & x)
+{
+       return -sinh(GiNaC::imag_part(x))*sin(GiNaC::real_part(x));
+}
+
+static ex cos_conjugate(const ex & x)
+{
+       // conjugate(cos(x))==cos(conjugate(x))
+       return cos(x.conjugate());
+}
+
 REGISTER_FUNCTION(cos, eval_func(cos_eval).
                        evalf_func(cos_evalf).
                        derivative_func(cos_deriv).
+                       real_part_func(cos_real_part).
+                       imag_part_func(cos_imag_part).
+                       conjugate_func(cos_conjugate).
                        latex_name("\\cos"));
 
 //////////
@@ -404,40 +612,43 @@ static ex tan_eval(const ex & x)
        const ex SixtyExOverPi = _ex60*x/Pi;
        ex sign = _ex1;
        if (SixtyExOverPi.info(info_flags::integer)) {
-               numeric z = mod(ex_to<numeric>(SixtyExOverPi),_num60);
-               if (z>=_num60) {
+               numeric z = mod(ex_to<numeric>(SixtyExOverPi),*_num60_p);
+               if (z>=*_num60_p) {
                        // wrap to interval [0, Pi)
-                       z -= _num60;
+                       z -= *_num60_p;
                }
-               if (z>=_num30) {
+               if (z>=*_num30_p) {
                        // wrap to interval [0, Pi/2)
-                       z = _num60-z;
+                       z = *_num60_p-z;
                        sign = _ex_1;
                }
-               if (z.is_equal(_num0))  // tan(0)       -> 0
+               if (z.is_equal(*_num0_p))  // tan(0)       -> 0
                        return _ex0;
-               if (z.is_equal(_num5))  // tan(Pi/12)   -> 2-sqrt(3)
+               if (z.is_equal(*_num5_p))  // tan(Pi/12)   -> 2-sqrt(3)
                        return sign*(_ex2-sqrt(_ex3));
-               if (z.is_equal(_num10)) // tan(Pi/6)    -> sqrt(3)/3
+               if (z.is_equal(*_num10_p)) // tan(Pi/6)    -> sqrt(3)/3
                        return sign*_ex1_3*sqrt(_ex3);
-               if (z.is_equal(_num15)) // tan(Pi/4)    -> 1
+               if (z.is_equal(*_num15_p)) // tan(Pi/4)    -> 1
                        return sign;
-               if (z.is_equal(_num20)) // tan(Pi/3)    -> sqrt(3)
+               if (z.is_equal(*_num20_p)) // tan(Pi/3)    -> sqrt(3)
                        return sign*sqrt(_ex3);
-               if (z.is_equal(_num25)) // tan(5/12*Pi) -> 2+sqrt(3)
+               if (z.is_equal(*_num25_p)) // tan(5/12*Pi) -> 2+sqrt(3)
                        return sign*(sqrt(_ex3)+_ex2);
-               if (z.is_equal(_num30)) // tan(Pi/2)    -> infinity
+               if (z.is_equal(*_num30_p)) // tan(Pi/2)    -> infinity
                        throw (pole_error("tan_eval(): simple pole",1));
        }
-       
+
        if (is_exactly_a<function>(x)) {
                const ex &t = x.op(0);
+
                // tan(atan(x)) -> x
                if (is_ex_the_function(x, atan))
                        return t;
+
                // tan(asin(x)) -> x/sqrt(1+x^2)
                if (is_ex_the_function(x, asin))
                        return t*power(_ex1-power(t,_ex2),_ex_1_2);
+
                // tan(acos(x)) -> sqrt(1-x^2)/x
                if (is_ex_the_function(x, acos))
                        return power(t,_ex_1)*sqrt(_ex1-power(t,_ex2));
@@ -448,6 +659,10 @@ static ex tan_eval(const ex & x)
                return tan(ex_to<numeric>(x));
        }
        
+       // tan() is odd
+       if (x.info(info_flags::negative))
+               return -tan(-x);
+       
        return tan(x).hold();
 }
 
@@ -459,6 +674,20 @@ static ex tan_deriv(const ex & x, unsigned deriv_param)
        return (_ex1+power(tan(x),_ex2));
 }
 
+static ex tan_real_part(const ex & x)
+{
+       ex a = GiNaC::real_part(x);
+       ex b = GiNaC::imag_part(x);
+       return tan(a)/(1+power(tan(a),2)*power(tan(b),2));
+}
+
+static ex tan_imag_part(const ex & x)
+{
+       ex a = GiNaC::real_part(x);
+       ex b = GiNaC::imag_part(x);
+       return tanh(b)/(1+power(tan(a),2)*power(tan(b),2));
+}
+
 static ex tan_series(const ex &x,
                      const relational &rel,
                      int order,
@@ -475,10 +704,19 @@ static ex tan_series(const ex &x,
        return (sin(x)/cos(x)).series(rel, order, options);
 }
 
+static ex tan_conjugate(const ex & x)
+{
+       // conjugate(tan(x))==tan(conjugate(x))
+       return tan(x.conjugate());
+}
+
 REGISTER_FUNCTION(tan, eval_func(tan_eval).
                        evalf_func(tan_evalf).
                        derivative_func(tan_deriv).
                        series_func(tan_series).
+                       real_part_func(tan_real_part).
+                       imag_part_func(tan_imag_part).
+                       conjugate_func(tan_conjugate).
                        latex_name("\\tan"));
 
 //////////
@@ -496,24 +734,34 @@ static ex asin_evalf(const ex & x)
 static ex asin_eval(const ex & x)
 {
        if (x.info(info_flags::numeric)) {
+
                // asin(0) -> 0
                if (x.is_zero())
                        return x;
+
                // asin(1/2) -> Pi/6
                if (x.is_equal(_ex1_2))
                        return numeric(1,6)*Pi;
+
                // asin(1) -> Pi/2
                if (x.is_equal(_ex1))
-                       return _num1_2*Pi;
+                       return _ex1_2*Pi;
+
                // asin(-1/2) -> -Pi/6
                if (x.is_equal(_ex_1_2))
                        return numeric(-1,6)*Pi;
+
                // asin(-1) -> -Pi/2
                if (x.is_equal(_ex_1))
-                       return _num_1_2*Pi;
+                       return _ex_1_2*Pi;
+
                // asin(float) -> float
                if (!x.info(info_flags::crational))
                        return asin(ex_to<numeric>(x));
+
+               // asin() is odd
+               if (x.info(info_flags::negative))
+                       return -asin(-x);
        }
        
        return asin(x).hold();
@@ -527,9 +775,21 @@ static ex asin_deriv(const ex & x, unsigned deriv_param)
        return power(1-power(x,_ex2),_ex_1_2);
 }
 
+static ex asin_conjugate(const ex & x)
+{
+       // conjugate(asin(x))==asin(conjugate(x)) unless on the branch cuts which
+       // run along the real axis outside the interval [-1, +1].
+       if (is_exactly_a<numeric>(x) &&
+           (!x.imag_part().is_zero() || (x > *_num_1_p && x < *_num1_p))) {
+               return asin(x.conjugate());
+       }
+       return conjugate_function(asin(x)).hold();
+}
+
 REGISTER_FUNCTION(asin, eval_func(asin_eval).
                         evalf_func(asin_evalf).
                         derivative_func(asin_deriv).
+                        conjugate_func(asin_conjugate).
                         latex_name("\\arcsin"));
 
 //////////
@@ -547,24 +807,34 @@ static ex acos_evalf(const ex & x)
 static ex acos_eval(const ex & x)
 {
        if (x.info(info_flags::numeric)) {
+
                // acos(1) -> 0
                if (x.is_equal(_ex1))
                        return _ex0;
+
                // acos(1/2) -> Pi/3
                if (x.is_equal(_ex1_2))
                        return _ex1_3*Pi;
+
                // acos(0) -> Pi/2
                if (x.is_zero())
                        return _ex1_2*Pi;
+
                // acos(-1/2) -> 2/3*Pi
                if (x.is_equal(_ex_1_2))
                        return numeric(2,3)*Pi;
+
                // acos(-1) -> Pi
                if (x.is_equal(_ex_1))
                        return Pi;
+
                // acos(float) -> float
                if (!x.info(info_flags::crational))
                        return acos(ex_to<numeric>(x));
+
+               // acos(-x) -> Pi-acos(x)
+               if (x.info(info_flags::negative))
+                       return Pi-acos(-x);
        }
        
        return acos(x).hold();
@@ -578,9 +848,21 @@ static ex acos_deriv(const ex & x, unsigned deriv_param)
        return -power(1-power(x,_ex2),_ex_1_2);
 }
 
+static ex acos_conjugate(const ex & x)
+{
+       // conjugate(acos(x))==acos(conjugate(x)) unless on the branch cuts which
+       // run along the real axis outside the interval [-1, +1].
+       if (is_exactly_a<numeric>(x) &&
+           (!x.imag_part().is_zero() || (x > *_num_1_p && x < *_num1_p))) {
+               return acos(x.conjugate());
+       }
+       return conjugate_function(acos(x)).hold();
+}
+
 REGISTER_FUNCTION(acos, eval_func(acos_eval).
                         evalf_func(acos_evalf).
                         derivative_func(acos_deriv).
+                        conjugate_func(acos_conjugate).
                         latex_name("\\arccos"));
 
 //////////
@@ -598,20 +880,29 @@ static ex atan_evalf(const ex & x)
 static ex atan_eval(const ex & x)
 {
        if (x.info(info_flags::numeric)) {
+
                // atan(0) -> 0
                if (x.is_zero())
                        return _ex0;
+
                // atan(1) -> Pi/4
                if (x.is_equal(_ex1))
                        return _ex1_4*Pi;
+
                // atan(-1) -> -Pi/4
                if (x.is_equal(_ex_1))
                        return _ex_1_4*Pi;
+
                if (x.is_equal(I) || x.is_equal(-I))
                        throw (pole_error("atan_eval(): logarithmic pole",0));
+
                // atan(float) -> float
                if (!x.info(info_flags::crational))
                        return atan(ex_to<numeric>(x));
+
+               // atan() is odd
+               if (x.info(info_flags::negative))
+                       return -atan(-x);
        }
        
        return atan(x).hold();
@@ -661,17 +952,37 @@ static ex atan_series(const ex &arg,
                else
                        Order0correction += log((I*arg_pt+_ex1)/(I*arg_pt+_ex_1))*I*_ex1_2;
                epvector seq;
-               seq.push_back(expair(Order0correction, _ex0));
+               if (order > 0) {
+                       seq.reserve(2);
+                       seq.push_back(expair(Order0correction, _ex0));
+               }
                seq.push_back(expair(Order(_ex1), order));
-               return series(replarg - pseries(rel, seq), rel, order);
+               return series(replarg - pseries(rel, std::move(seq)), rel, order);
        }
        throw do_taylor();
 }
 
+static ex atan_conjugate(const ex & x)
+{
+       // conjugate(atan(x))==atan(conjugate(x)) unless on the branch cuts which
+       // run along the imaginary axis outside the interval [-I, +I].
+       if (x.info(info_flags::real))
+               return atan(x);
+       if (is_exactly_a<numeric>(x)) {
+               const numeric x_re = ex_to<numeric>(x.real_part());
+               const numeric x_im = ex_to<numeric>(x.imag_part());
+               if (!x_re.is_zero() ||
+                   (x_im > *_num_1_p && x_im < *_num1_p))
+                       return atan(x.conjugate());
+       }
+       return conjugate_function(atan(x)).hold();
+}
+
 REGISTER_FUNCTION(atan, eval_func(atan_eval).
                         evalf_func(atan_evalf).
                         derivative_func(atan_deriv).
                         series_func(atan_series).
+                        conjugate_func(atan_conjugate).
                         latex_name("\\arctan"));
 
 //////////
@@ -681,19 +992,80 @@ REGISTER_FUNCTION(atan, eval_func(atan_eval).
 static ex atan2_evalf(const ex &y, const ex &x)
 {
        if (is_exactly_a<numeric>(y) && is_exactly_a<numeric>(x))
-               return atan2(ex_to<numeric>(y), ex_to<numeric>(x));
+               return atan(ex_to<numeric>(y), ex_to<numeric>(x));
        
        return atan2(y, x).hold();
 }
 
 static ex atan2_eval(const ex & y, const ex & x)
 {
-       if (y.info(info_flags::numeric) && !y.info(info_flags::crational) &&
-               x.info(info_flags::numeric) && !x.info(info_flags::crational)) {
-               return atan2_evalf(y,x);
+       if (y.is_zero()) {
+
+               // atan2(0, 0) -> 0
+               if (x.is_zero())
+                       return _ex0;
+
+               // atan2(0, x), x real and positive -> 0
+               if (x.info(info_flags::positive))
+                       return _ex0;
+
+               // atan2(0, x), x real and negative -> Pi
+               if (x.info(info_flags::negative))
+                       return Pi;
        }
-       
-       return atan2(y,x).hold();
+
+       if (x.is_zero()) {
+
+               // atan2(y, 0), y real and positive -> Pi/2
+               if (y.info(info_flags::positive))
+                       return _ex1_2*Pi;
+
+               // atan2(y, 0), y real and negative -> -Pi/2
+               if (y.info(info_flags::negative))
+                       return _ex_1_2*Pi;
+       }
+
+       if (y.is_equal(x)) {
+
+               // atan2(y, y), y real and positive -> Pi/4
+               if (y.info(info_flags::positive))
+                       return _ex1_4*Pi;
+
+               // atan2(y, y), y real and negative -> -3/4*Pi
+               if (y.info(info_flags::negative))
+                       return numeric(-3, 4)*Pi;
+       }
+
+       if (y.is_equal(-x)) {
+
+               // atan2(y, -y), y real and positive -> 3*Pi/4
+               if (y.info(info_flags::positive))
+                       return numeric(3, 4)*Pi;
+
+               // atan2(y, -y), y real and negative -> -Pi/4
+               if (y.info(info_flags::negative))
+                       return _ex_1_4*Pi;
+       }
+
+       // atan2(float, float) -> float
+       if (is_a<numeric>(y) && !y.info(info_flags::crational) &&
+           is_a<numeric>(x) && !x.info(info_flags::crational))
+               return atan(ex_to<numeric>(y), ex_to<numeric>(x));
+
+       // atan2(real, real) -> atan(y/x) +/- Pi
+       if (y.info(info_flags::real) && x.info(info_flags::real)) {
+               if (x.info(info_flags::positive))
+                       return atan(y/x);
+
+               if (x.info(info_flags::negative)) {
+                       if (y.info(info_flags::positive))
+                               return atan(y/x)+Pi;
+                       if (y.info(info_flags::negative))
+                               return atan(y/x)-Pi;
+               }
+       }
+
+       return atan2(y, x).hold();
 }    
 
 static ex atan2_deriv(const ex & y, const ex & x, unsigned deriv_param)
@@ -701,10 +1073,10 @@ static ex atan2_deriv(const ex & y, const ex & x, unsigned deriv_param)
        GINAC_ASSERT(deriv_param<2);
        
        if (deriv_param==0) {
-               // d/dy atan(y,x)
+               // d/dy atan2(y,x)
                return x*power(power(x,_ex2)+power(y,_ex2),_ex_1);
        }
-       // d/dx atan(y,x)
+       // d/dx atan2(y,x)
        return -y*power(power(x,_ex2)+power(y,_ex2),_ex_1);
 }
 
@@ -727,10 +1099,18 @@ static ex sinh_evalf(const ex & x)
 static ex sinh_eval(const ex & x)
 {
        if (x.info(info_flags::numeric)) {
-               if (x.is_zero())  // sinh(0) -> 0
+
+               // sinh(0) -> 0
+               if (x.is_zero())
                        return _ex0;        
-               if (!x.info(info_flags::crational))  // sinh(float) -> float
+
+               // sinh(float) -> float
+               if (!x.info(info_flags::crational))
                        return sinh(ex_to<numeric>(x));
+
+               // sinh() is odd
+               if (x.info(info_flags::negative))
+                       return -sinh(-x);
        }
        
        if ((x/Pi).info(info_flags::numeric) &&
@@ -739,12 +1119,15 @@ static ex sinh_eval(const ex & x)
        
        if (is_exactly_a<function>(x)) {
                const ex &t = x.op(0);
+
                // sinh(asinh(x)) -> x
                if (is_ex_the_function(x, asinh))
                        return t;
+
                // sinh(acosh(x)) -> sqrt(x-1) * sqrt(x+1)
                if (is_ex_the_function(x, acosh))
                        return sqrt(t-_ex1)*sqrt(t+_ex1);
+
                // sinh(atanh(x)) -> x/sqrt(1-x^2)
                if (is_ex_the_function(x, atanh))
                        return t*power(_ex1-power(t,_ex2),_ex_1_2);
@@ -761,9 +1144,28 @@ static ex sinh_deriv(const ex & x, unsigned deriv_param)
        return cosh(x);
 }
 
+static ex sinh_real_part(const ex & x)
+{
+       return sinh(GiNaC::real_part(x))*cos(GiNaC::imag_part(x));
+}
+
+static ex sinh_imag_part(const ex & x)
+{
+       return cosh(GiNaC::real_part(x))*sin(GiNaC::imag_part(x));
+}
+
+static ex sinh_conjugate(const ex & x)
+{
+       // conjugate(sinh(x))==sinh(conjugate(x))
+       return sinh(x.conjugate());
+}
+
 REGISTER_FUNCTION(sinh, eval_func(sinh_eval).
                         evalf_func(sinh_evalf).
                         derivative_func(sinh_deriv).
+                        real_part_func(sinh_real_part).
+                        imag_part_func(sinh_imag_part).
+                        conjugate_func(sinh_conjugate).
                         latex_name("\\sinh"));
 
 //////////
@@ -781,10 +1183,18 @@ static ex cosh_evalf(const ex & x)
 static ex cosh_eval(const ex & x)
 {
        if (x.info(info_flags::numeric)) {
-               if (x.is_zero())  // cosh(0) -> 1
+
+               // cosh(0) -> 1
+               if (x.is_zero())
                        return _ex1;
-               if (!x.info(info_flags::crational))  // cosh(float) -> float
+
+               // cosh(float) -> float
+               if (!x.info(info_flags::crational))
                        return cosh(ex_to<numeric>(x));
+
+               // cosh() is even
+               if (x.info(info_flags::negative))
+                       return cosh(-x);
        }
        
        if ((x/Pi).info(info_flags::numeric) &&
@@ -793,12 +1203,15 @@ static ex cosh_eval(const ex & x)
        
        if (is_exactly_a<function>(x)) {
                const ex &t = x.op(0);
+
                // cosh(acosh(x)) -> x
                if (is_ex_the_function(x, acosh))
                        return t;
+
                // cosh(asinh(x)) -> sqrt(1+x^2)
                if (is_ex_the_function(x, asinh))
                        return sqrt(_ex1+power(t,_ex2));
+
                // cosh(atanh(x)) -> 1/sqrt(1-x^2)
                if (is_ex_the_function(x, atanh))
                        return power(_ex1-power(t,_ex2),_ex_1_2);
@@ -815,9 +1228,28 @@ static ex cosh_deriv(const ex & x, unsigned deriv_param)
        return sinh(x);
 }
 
+static ex cosh_real_part(const ex & x)
+{
+       return cosh(GiNaC::real_part(x))*cos(GiNaC::imag_part(x));
+}
+
+static ex cosh_imag_part(const ex & x)
+{
+       return sinh(GiNaC::real_part(x))*sin(GiNaC::imag_part(x));
+}
+
+static ex cosh_conjugate(const ex & x)
+{
+       // conjugate(cosh(x))==cosh(conjugate(x))
+       return cosh(x.conjugate());
+}
+
 REGISTER_FUNCTION(cosh, eval_func(cosh_eval).
                         evalf_func(cosh_evalf).
                         derivative_func(cosh_deriv).
+                        real_part_func(cosh_real_part).
+                        imag_part_func(cosh_imag_part).
+                        conjugate_func(cosh_conjugate).
                         latex_name("\\cosh"));
 
 //////////
@@ -835,10 +1267,18 @@ static ex tanh_evalf(const ex & x)
 static ex tanh_eval(const ex & x)
 {
        if (x.info(info_flags::numeric)) {
-               if (x.is_zero())  // tanh(0) -> 0
+
+               // tanh(0) -> 0
+               if (x.is_zero())
                        return _ex0;
-               if (!x.info(info_flags::crational))  // tanh(float) -> float
+
+               // tanh(float) -> float
+               if (!x.info(info_flags::crational))
                        return tanh(ex_to<numeric>(x));
+
+               // tanh() is odd
+               if (x.info(info_flags::negative))
+                       return -tanh(-x);
        }
        
        if ((x/Pi).info(info_flags::numeric) &&
@@ -847,12 +1287,15 @@ static ex tanh_eval(const ex & x)
        
        if (is_exactly_a<function>(x)) {
                const ex &t = x.op(0);
+
                // tanh(atanh(x)) -> x
                if (is_ex_the_function(x, atanh))
                        return t;
+
                // tanh(asinh(x)) -> x/sqrt(1+x^2)
                if (is_ex_the_function(x, asinh))
                        return t*power(_ex1+power(t,_ex2),_ex_1_2);
+
                // tanh(acosh(x)) -> sqrt(x-1)*sqrt(x+1)/x
                if (is_ex_the_function(x, acosh))
                        return sqrt(t-_ex1)*sqrt(t+_ex1)*power(t,_ex_1);
@@ -885,10 +1328,33 @@ static ex tanh_series(const ex &x,
        return (sinh(x)/cosh(x)).series(rel, order, options);
 }
 
+static ex tanh_real_part(const ex & x)
+{
+       ex a = GiNaC::real_part(x);
+       ex b = GiNaC::imag_part(x);
+       return tanh(a)/(1+power(tanh(a),2)*power(tan(b),2));
+}
+
+static ex tanh_imag_part(const ex & x)
+{
+       ex a = GiNaC::real_part(x);
+       ex b = GiNaC::imag_part(x);
+       return tan(b)/(1+power(tanh(a),2)*power(tan(b),2));
+}
+
+static ex tanh_conjugate(const ex & x)
+{
+       // conjugate(tanh(x))==tanh(conjugate(x))
+       return tanh(x.conjugate());
+}
+
 REGISTER_FUNCTION(tanh, eval_func(tanh_eval).
                         evalf_func(tanh_evalf).
                         derivative_func(tanh_deriv).
                         series_func(tanh_series).
+                        real_part_func(tanh_real_part).
+                        imag_part_func(tanh_imag_part).
+                        conjugate_func(tanh_conjugate).
                         latex_name("\\tanh"));
 
 //////////
@@ -906,12 +1372,18 @@ static ex asinh_evalf(const ex & x)
 static ex asinh_eval(const ex & x)
 {
        if (x.info(info_flags::numeric)) {
+
                // asinh(0) -> 0
                if (x.is_zero())
                        return _ex0;
+
                // asinh(float) -> float
                if (!x.info(info_flags::crational))
                        return asinh(ex_to<numeric>(x));
+
+               // asinh() is odd
+               if (x.info(info_flags::negative))
+                       return -asinh(-x);
        }
        
        return asinh(x).hold();
@@ -925,9 +1397,26 @@ static ex asinh_deriv(const ex & x, unsigned deriv_param)
        return power(_ex1+power(x,_ex2),_ex_1_2);
 }
 
+static ex asinh_conjugate(const ex & x)
+{
+       // conjugate(asinh(x))==asinh(conjugate(x)) unless on the branch cuts which
+       // run along the imaginary axis outside the interval [-I, +I].
+       if (x.info(info_flags::real))
+               return asinh(x);
+       if (is_exactly_a<numeric>(x)) {
+               const numeric x_re = ex_to<numeric>(x.real_part());
+               const numeric x_im = ex_to<numeric>(x.imag_part());
+               if (!x_re.is_zero() ||
+                   (x_im > *_num_1_p && x_im < *_num1_p))
+                       return asinh(x.conjugate());
+       }
+       return conjugate_function(asinh(x)).hold();
+}
+
 REGISTER_FUNCTION(asinh, eval_func(asinh_eval).
                          evalf_func(asinh_evalf).
-                         derivative_func(asinh_deriv));
+                         derivative_func(asinh_deriv).
+                         conjugate_func(asinh_conjugate));
 
 //////////
 // inverse hyperbolic cosine (trigonometric function)
@@ -944,18 +1433,26 @@ static ex acosh_evalf(const ex & x)
 static ex acosh_eval(const ex & x)
 {
        if (x.info(info_flags::numeric)) {
+
                // acosh(0) -> Pi*I/2
                if (x.is_zero())
                        return Pi*I*numeric(1,2);
+
                // acosh(1) -> 0
                if (x.is_equal(_ex1))
                        return _ex0;
+
                // acosh(-1) -> Pi*I
                if (x.is_equal(_ex_1))
                        return Pi*I;
+
                // acosh(float) -> float
                if (!x.info(info_flags::crational))
                        return acosh(ex_to<numeric>(x));
+
+               // acosh(-x) -> Pi*I-acosh(x)
+               if (x.info(info_flags::negative))
+                       return Pi*I-acosh(-x);
        }
        
        return acosh(x).hold();
@@ -969,9 +1466,21 @@ static ex acosh_deriv(const ex & x, unsigned deriv_param)
        return power(x+_ex_1,_ex_1_2)*power(x+_ex1,_ex_1_2);
 }
 
+static ex acosh_conjugate(const ex & x)
+{
+       // conjugate(acosh(x))==acosh(conjugate(x)) unless on the branch cut
+       // which runs along the real axis from +1 to -inf.
+       if (is_exactly_a<numeric>(x) &&
+           (!x.imag_part().is_zero() || x > *_num1_p)) {
+               return acosh(x.conjugate());
+       }
+       return conjugate_function(acosh(x)).hold();
+}
+
 REGISTER_FUNCTION(acosh, eval_func(acosh_eval).
                          evalf_func(acosh_evalf).
-                         derivative_func(acosh_deriv));
+                         derivative_func(acosh_deriv).
+                         conjugate_func(acosh_conjugate));
 
 //////////
 // inverse hyperbolic tangent (trigonometric function)
@@ -988,15 +1497,22 @@ static ex atanh_evalf(const ex & x)
 static ex atanh_eval(const ex & x)
 {
        if (x.info(info_flags::numeric)) {
+
                // atanh(0) -> 0
                if (x.is_zero())
                        return _ex0;
+
                // atanh({+|-}1) -> throw
                if (x.is_equal(_ex1) || x.is_equal(_ex_1))
                        throw (pole_error("atanh_eval(): logarithmic pole",0));
+
                // atanh(float) -> float
                if (!x.info(info_flags::crational))
                        return atanh(ex_to<numeric>(x));
+
+               // atanh() is odd
+               if (x.info(info_flags::negative))
+                       return -atanh(-x);
        }
        
        return atanh(x).hold();
@@ -1033,30 +1549,45 @@ static ex atanh_series(const ex &arg,
                return ((log(_ex1+arg)-log(_ex1-arg))*_ex1_2).series(rel, order, options);
        // ...and the branch cuts (the discontinuity at the cut being just I*Pi)
        if (!(options & series_options::suppress_branchcut)) {
-               // method:
-               // This is the branch cut: assemble the primitive series manually and
-               // then add the corresponding complex step function.
-               const symbol &s = ex_to<symbol>(rel.lhs());
-               const ex &point = rel.rhs();
-               const symbol foo;
-               const ex replarg = series(atanh(arg), s==foo, order).subs(foo==point, subs_options::no_pattern);
+               // method:
+               // This is the branch cut: assemble the primitive series manually and
+               // then add the corresponding complex step function.
+               const symbol &s = ex_to<symbol>(rel.lhs());
+               const ex &point = rel.rhs();
+               const symbol foo;
+               const ex replarg = series(atanh(arg), s==foo, order).subs(foo==point, subs_options::no_pattern);
                ex Order0correction = replarg.op(0)+csgn(I*arg)*Pi*I*_ex1_2;
                if (arg_pt<_ex0)
                        Order0correction += log((arg_pt+_ex_1)/(arg_pt+_ex1))*_ex1_2;
                else
                        Order0correction += log((arg_pt+_ex1)/(arg_pt+_ex_1))*_ex_1_2;
-               epvector seq;
-               seq.push_back(expair(Order0correction, _ex0));
-               seq.push_back(expair(Order(_ex1), order));
-               return series(replarg - pseries(rel, seq), rel, order);
+               epvector seq;
+               if (order > 0) {
+                       seq.reserve(2);
+                       seq.push_back(expair(Order0correction, _ex0));
+               }
+               seq.push_back(expair(Order(_ex1), order));
+               return series(replarg - pseries(rel, std::move(seq)), rel, order);
        }
        throw do_taylor();
 }
 
+static ex atanh_conjugate(const ex & x)
+{
+       // conjugate(atanh(x))==atanh(conjugate(x)) unless on the branch cuts which
+       // run along the real axis outside the interval [-1, +1].
+       if (is_exactly_a<numeric>(x) &&
+           (!x.imag_part().is_zero() || (x > *_num_1_p && x < *_num1_p))) {
+               return atanh(x.conjugate());
+       }
+       return conjugate_function(atanh(x)).hold();
+}
+
 REGISTER_FUNCTION(atanh, eval_func(atanh_eval).
                          evalf_func(atanh_evalf).
                          derivative_func(atanh_deriv).
-                         series_func(atanh_series));
+                         series_func(atanh_series).
+                         conjugate_func(atanh_conjugate));
 
 
 } // namespace GiNaC