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Von: maxima-bounces at math.utexas.edu [mailto:maxima-bounces at math.utexas.edu] Im
Auftrag von Alexey Beshenov
Gesendet: Sonntag, 18. Januar 2009 19:52
An: Robert Dodier
Cc: maxima at math.utexas.edu
Betreff: Re: [Maxima] sign(zeta(x))
> sign-zeta is my function; I'm not sure how to add it to the
> sign-related functions from compar.lisp in an appropriate way.
I have done some work in the file compar.lisp to add the function $csign.
The most simple way would be to add a line of code to the Lisp function SIGN:
((eq (caar x) '$zeta) (sign-zeta x))
But to work with $sign the function sign-zeta has to be modified a bit. $sign
uses global variables which have to be set correctly by the routine sign-zeta.
When we do this the sign of an expression with a zeta function will work too.
If it is of interest I could propose the code in the next days.
Dieter Kaiser