From: Christian Bauer <Christian.Bauer@uni-mainz.de>
Date: Fri, 25 May 2001 22:29:34 +0000 (+0000)
Subject: mentioned ncpow()
X-Git-Tag: release_0-9-0~34
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=76e316dae12aac0216a0d7f701e35911240b5d5c;hp=316405c8b75a62d2ae63074bfd3a60c6661bfbbb

mentioned ncpow()
---

diff --git a/doc/tutorial/ginac.texi b/doc/tutorial/ginac.texi
index 12d7035d..c5841b8a 100644
--- a/doc/tutorial/ginac.texi
+++ b/doc/tutorial/ginac.texi
@@ -1970,6 +1970,16 @@ Other representation labels yield a different @code{return_type_tinfo()},
 but it's the same for any two objects with the same label. This is also true
 for color objects.
 
+As a last note, powers of non-commutative objects are not allowed in GiNaC.
+You can use the function
+
+@example
+ex ncpow(const ex & basis, unsigned exponent)
+@end example
+
+instead which returns an expanded product (e.g. @code{ncpow(a*b, 2)} becomes
+@samp{a*b*a*b} if @samp{a} and @samp{b} are non-commutative expressions).
+
 
 @cindex @code{clifford} (class)
 @subsection Clifford algebra
@@ -2799,7 +2809,7 @@ The last example would be written in C++ in this way:
     e = a*pow(sin(x+y), 2) + a*pow(cos(x+y), 2) + b;
     e = e.subs(pow(cos(wild()), 2) == 1-pow(sin(wild()), 2));
     cout << e.expand() << endl;
-     // -> "b+a"
+     // -> a+b
 @}
 @end example