how to load(sign-shift.lisp) in wxmaxima 0.8.0


On Sun, 11 Oct 2009, Dieter Kaiser wrote:

< Am Sonntag, den 11.10.2009, 12:43 +0800 schrieb ? ??:
< > how to load(sign-shift.lisp) in wxmaxima 0.8.0
< > 
< > I read form Maxima Digest, Vol 39, Issue 33 and  try to
< > load(sign-shift.lisp)
< > (%i4) load(sign-shift.lisp)
< > Could not find `sign-shift.lisp' using paths in
< > file_search_maxima,file_search_lisp.
< >  -- an error.  To debug this try debugmode(true);
< 
< Thank you very much for your interest.
< 
< The code is under development. You cannot download it. You can try to
< cut it out of the postings. But I think you might have some problems to
< get it to work. 
< 
< First I have thought that I have found a simple way to improve the
< functionality of assume in general. The code as it is, works with the
< testsuite and the share_testsuite.
< 
< But there is a big problem. The code improves cases like assume(a>1,b>1)
< and gets the correct sign for sign(a+b-2). It works for much more
< complicated expressions too, but not as general as I thought. We do not
< have very general examples in the testsuite, because we do not assume
< that this more general cases will work.
< 
 
Dieter, I would like to have this functionality. At the moment, I am
frustrated because with

assume(n>0,i>0,j>0,n>=i,n>=j);

maxima cannot determine that

is(equal(n+i-j,0));

is false. Is your code able to do this?

Leo
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