function(unsigned, const exprseq &) constructor clears status_flags::evaluated

[ginac.git] / ginac / power.cpp

diff --git a/ginac/power.cpp b/ginac/power.cpp
index 85e5bd6c9a92e76c470dc83c527a4d6eaa85a0d0..0730e3c8bf7fc385c5d4d1c1a97b6c565997cfab 100644 (file)
--- a/ginac/power.cpp
+++ b/ginac/power.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's symbolic exponentiation (basis^exponent). */
 
 /*
- *  GiNaC Copyright (C) 1999-2002 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2003 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
@@ -125,7 +125,7 @@ void power::print(const print_context & c, unsigned level) const
 
                // Integer powers of symbols are printed in a special, optimized way
                if (exponent.info(info_flags::integer)
-                && (is_exactly_a<symbol>(basis) || is_exactly_a<constant>(basis))) {
+                && (is_a<symbol>(basis) || is_a<constant>(basis))) {
                        int exp = ex_to<numeric>(exponent).to_int();
                        if (exp > 0)
                                c.s << '(';
@@ -172,11 +172,23 @@ void power::print(const print_context & c, unsigned level) const
 
                bool is_tex = is_a<print_latex>(c);
 
-               if (exponent.is_equal(_ex1_2)) {
+               if (is_tex && is_exactly_a<numeric>(exponent) && ex_to<numeric>(exponent).is_negative()) {
+
+                       // Powers with negative numeric exponents are printed as fractions in TeX
+                       c.s << "\\frac{1}{";
+                       power(basis, -exponent).eval().print(c);
+                       c.s << "}";
+
+               } else if (exponent.is_equal(_ex1_2)) {
+
+                       // Square roots are printed in a special way
                        c.s << (is_tex ? "\\sqrt{" : "sqrt(");
                        basis.print(c);
                        c.s << (is_tex ? '}' : ')');
+
                } else {
+
+                       // Ordinary output of powers using '^' or '**'
                        if (precedence() <= level)
                                c.s << (is_tex ? "{(" : "(");
                        basis.print(c, precedence());