Introduce status_flags::{is_positive,is_negative,purely_indefinite}

[ginac.git] / ginac / power.cpp

diff --git a/ginac/power.cpp b/ginac/power.cpp
index d8c9b4efc9d4f692d5a725627532a26a9da0e3f2..b815d17a9e6e07f716748ff909c81dc080835994 100644 (file)
--- a/ginac/power.cpp
+++ b/ginac/power.cpp
@@ -362,7 +362,7 @@ ex power::coeff(const ex & s, int n) const
  *  - ^(1,x) -> 1
  *  - ^(c1,c2) -> *(c1^n,c1^(c2-n))  (so that 0<(c2-n)<1, try to evaluate roots, possibly in numerator and denominator of c1)
  *  - ^(^(x,c1),c2) -> ^(x,c1*c2)  if x is positive and c1 is real.
- *  - ^(^(x,c1),c2) -> ^(x,c1*c2)  (c2 integer or -1 < c1 <= 1, case c1=1 should not happen, see below!)
+ *  - ^(^(x,c1),c2) -> ^(x,c1*c2)  (c2 integer or -1 < c1 <= 1 or (c1=-1 and c2>0), case c1=1 should not happen, see below!)
  *  - ^(*(x,y,z),c) -> *(x^c,y^c,z^c)  (if c integer)
  *  - ^(*(x,c1),c2) -> ^(x,c2)*c1^c2  (c1>0)
  *  - ^(*(x,c1),c2) -> ^(-x,c2)*c1^c2  (c1<0)
@@ -480,7 +480,7 @@ ex power::eval(int level) const
                }
        
                // ^(^(x,c1),c2) -> ^(x,c1*c2)
-               // (c1, c2 numeric(), c2 integer or -1 < c1 <= 1,
+               // (c1, c2 numeric(), c2 integer or -1 < c1 <= 1 or (c1=-1 and c2>0),
                // case c1==1 should not happen, see below!)
                if (is_exactly_a<power>(ebasis)) {
                        const power & sub_power = ex_to<power>(ebasis);
@@ -489,7 +489,8 @@ ex power::eval(int level) const
                        if (is_exactly_a<numeric>(sub_exponent)) {
                                const numeric & num_sub_exponent = ex_to<numeric>(sub_exponent);
                                GINAC_ASSERT(num_sub_exponent!=numeric(1));
-                               if (num_exponent->is_integer() || (abs(num_sub_exponent) - (*_num1_p)).is_negative()) {
+                               if (num_exponent->is_integer() || (abs(num_sub_exponent) - (*_num1_p)).is_negative() 
+                                               || (num_sub_exponent == *_num_1_p && num_exponent->is_positive())) {
                                        return power(sub_basis,num_sub_exponent.mul(*num_exponent));
                                }
                        }
@@ -735,8 +736,7 @@ ex power::imag_part() const
        ex b=basis.imag_part();
        ex c=exponent.real_part();
        ex d=exponent.imag_part();
-       return
-               power(abs(basis),c)*exp(-d*atan2(b,a))*sin(c*atan2(b,a)+d*log(abs(basis)));
+       return power(abs(basis),c)*exp(-d*atan2(b,a))*sin(c*atan2(b,a)+d*log(abs(basis)));
 }
 
 // protected