- Made determinant_algo (in flags.h) really work.

[ginac.git] / doc / tutorial / ginac.texi

diff --git a/doc/tutorial/ginac.texi b/doc/tutorial/ginac.texi
index ad044074eb19bed8933314c00d0b0d622ed49812..bc330c7d5aec5b7a4052dd01480f545c91178d79 100644 (file)
--- a/doc/tutorial/ginac.texi
+++ b/doc/tutorial/ginac.texi
@@ -2068,10 +2068,17 @@ GiNaC contains the following predefined mathematical functions:
 
 @cindex branch cut
 For functions that have a branch cut in the complex plane GiNaC follows
-the conventions for C++ as defined in the ANSI standard.  In particular:
-the natural logarithm (@code{log}) and the square root (@code{sqrt})
-both have their branch cuts running along the negative real axis where
-the points on the axis itself belong to the upper part.
+the conventions for C++ as defined in the ANSI standard as far as
+possible.  In particular: the natural logarithm (@code{log}) and the
+square root (@code{sqrt}) both have their branch cuts running along the
+negative real axis where the points on the axis itself belong to the
+upper part (i.e. continuous with quadrant II).  The inverse
+trigonometric and hyperbolic functions are not defined for complex
+arguments by the C++ standard, however.  Here, we follow the conventions
+used by CLN, which in turn follow the carefully designed definitions
+in the Common Lisp standard.  Hopefully, future revisions of the C++
+standard incorporate these functions in the complex domain in a manner
+compatible with Common Lisp.
 
 
 @node Input/Output, Extending GiNaC, Built-in Functions, Methods and Functions