Hi! Stephen Montgomery-Smith wrote:
Vladimir V. Kisil wrote:
> On Fri, 02 Oct 2009 00:00:13 +0200, "Richard B. Kreckel" > <kreckel@ginac.de> said: RK> Maybe it is just too late, but I don't see the motivation for RK> the "is x an integer" condition.
Why not, if it is a correct substitution. Who know, may be as a result of some evaluation power of the exponents will becomes 2.
Actually, including "x is an integer" turns out to be correct. But we can do even better: it is sufficient to test if a is real. Here is a proof. With arbitrary complex b: pow(exp(a),b) == exp(b*log(exp(a)) Since a is real, we know that exp(a) is real and positive. So log(exp(a))==a and exp(b*log(exp(a))==exp(b*a). q.e.d. I'll push a patch for the exp function and for doc/powerlaws.tex.
I think it is wrong to include "x is an integer." Even 1^i (which is exp(0)^i) is not well defined (it can be any of e^(2 pi n) for all integers).
That argument is confused. After all, we rewrite exp(2*Pi*I) -> 1. -richy. -- Richard B. Kreckel <http://www.ginac.de/~kreckel/>