読者です 読者をやめる 読者になる 読者になる

Maxima さん,bug ってますよ.

Maxima 5.39.0 http://maxima.sourceforge.net
using Lisp CMU Common Lisp 21b (21B Unicode)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) assume(a>0,b>0);
(%o1)                           [a > 0, b > 0]
(%i2) assume(a*b<0);
(%o2)                           [inconsistent]
(%i3) forget(a>0,b>0);
(%o3)                           [a > 0, b > 0]
(%i4) assume(a*b<0);
(%o4)                              [a b < 0]
(%i5) assume(a>0,b>0);
(%o5)                           [a > 0, b > 0]
(%i6) facts();
(%o6)                       [0 > a b, a > 0, b > 0]
(%i7) forget(a>0,b>0,a*b<0);
(%o7)                       [a > 0, b > 0, a b < 0]
(%i8) sqrt(x)>0;
(%o8)                             sqrt(x) > 0
(%i9) is(%);
(%o9)                               unknown
(%i10) sqrt(x)>=0;
(%o10)                           sqrt(x) >= 0
(%i11) is(%);
(%o11)                               true