Tutorial: how to create noncommutative symbols?

This seems to be frequently asked:
<http://www.ginac.de/pipermail/ginac-devel/2015-November/002213.html>

diff --git a/doc/tutorial/ginac.texi b/doc/tutorial/ginac.texi
index dbbf2359e76764aad30e1615fb08a66d38d2b782..1b8a1a6a37e925bd7fc9ce9dba0de044b2c9015d 100644 (file)
--- a/doc/tutorial/ginac.texi
+++ b/doc/tutorial/ginac.texi
@@ -3033,6 +3033,8 @@ canonicalize themselves according to rules specified in the implementation
 of the non-commutative classes. The drawback is that to work with other than
 the built-in algebras you have to implement new classes yourself. Both
 symbols and user-defined functions can be specified as being non-commutative.
 of the non-commutative classes. The drawback is that to work with other than
 the built-in algebras you have to implement new classes yourself. Both
 symbols and user-defined functions can be specified as being non-commutative.

+For symbols, this is done by subclassing class symbol; for functions,
+by explicitly setting the return type (@pxref{Symbolic functions}).

 
 @cindex @code{return_type()}
 @cindex @code{return_type_tinfo()}
 
 @cindex @code{return_type()}
 @cindex @code{return_type_tinfo()}