Introduce expand_options::expand_transcendental.

In general expand() treats the argument as a rational expression (and
leave transcendental functions as they are). However sometimes it's
convenient to expand transcendental functions too, like

log(a*b) = log(a) + log(b)
exp(a + b) = exp(a)*exp(b)

Applying such transformation by default doesn't seem to be a smart idea
(think of log(p^2/mu^2) transformed to 2*log(p) - 2*log(mu)). Therefore
introduce expand_options::expand_transcendental. As the name implies expand()
tries to transform transcendental functions only if this flag is set.

Signed-off-by: Vladimir V. Kisil <kisilv@maths.leeds.ac.uk>

diff --git a/ginac/flags.h b/ginac/flags.h
index 3d398cf18619c6d0f5489c319ce48622b72591d3..6da71b0432e48ea0af5710a0300c222902602f86 100644 (file)
--- a/ginac/flags.h
+++ b/ginac/flags.h
@@ -31,7 +31,8 @@ public:
        enum {
                expand_indexed = 0x0001,      ///< expands (a+b).i to a.i+b.i
                expand_function_args = 0x0002, ///< expands the arguments of functions
-               expand_rename_idx = 0x0004 ///< used internally by mul::expand()
+               expand_rename_idx = 0x0004, ///< used internally by mul::expand()
+               expand_transcendental = 0x0008 ///< expands trancendental functions like log and exp
        };
 };