program works with maxima 5.29.1 but freezes with maxima 5.30.0



On 2013-04-16, Dmitry Shkirmanov <piminusmeson at bk.ru> wrote:

> Hello, list. I have wxmaxima program that takes a few seconds to run 
> with maxima 5.29.1. But  in maxima 5.30.0 it freezes.  Is there any way 
> to make it work with maxima 5.30?

I've confirmed that it works OK with 5.29.1 and doesn't with 5.30.0.
Looks like expressions are simplified differently -- expressions are
bigger in 5.30.0. I'm not sure what's going on -- many of the results
are the same, and of the ones that are different, I don't know exactly
why they are different. 

I looked at the git logs for src/simp.lisp and src/rat3e.lisp -- I don't
see any obvious culprit. To find the commit or commits which changed
behavior, I can't see anything more effective than bisecting the git
commit history.

I'll try to invest some more time, and I hope someone else can take a
look at it. Expressions that get too big seem to be a common problem in
Maxima -- I hope that we aren't making changes that make that more
likely, or, at least, if we are, then we understand the trade-offs.

best

Robert Dodier