I did use wxMaxima 0.8.2 with Maxima version: 5.18.1.
The interactions with (wx)Maxima given in the attached file ProblemWithforget.wxm show that "forget(a > 0)" after "assume(a > 0)" works well, but "forget(a : 0)" after "assume(a : 0)" does not work, and that in such case we have to use "kill(a)" in order to make Maxima forget about the predicate "a : 0". I do not know if that is a bug, but at first sight it is not very elegant.
Sender of this problem: ilitzroth
This is not a bug, it's normal behaviour.
assume doesn't work with a:0.
You can do this:
block([a:0], integrate(...) ).
Then, a will have the value 0 (only) inside the block.
As described in the last post this is not a bug. Closing this report and marking it as invalid.
Dieter Kaiser