Hello,
I am attempting to determine the sign of an expression, but I have
discovered that sign fails to solve even simpler problems than I am working
on.
%i1) assume(zi <= vi+ni*ci, zi>=0, vi>=0, ni>=0, ci>=0)$
%i2) sign(zi - vi - ni*ci);
%o2) pnz
In my mind the answer seems to clearly be pz.
Following from:
zi <= vi+ni*ci
zi -(vi+ni*ci) <= 0
zi -vi - ni*ci <= 0
I'm not sure if there is another package I have to include or what other
assumptions are needed. Maybe the sign function is incomplete? Maybe
inequalities are harder for Maxima to work with than equations?
BTW, I'm using maxima version 5.28.0-2.