>>>>> "Richard" == Richard Fateman <fateman at cs.berkeley.edu> writes:
Richard> I just had occasion to try hgfred. There are errors in simplification in
Richard> this program that allow it to generate
Richard> subexpressions like (1- -x) or even (1 - -36). Someone is producing
Richard> expressions with incorrect ((mtimes simp)..)
Richard> headers. Unfortunately I didn't catch the examples before my system
Richard> crashed. But there are other probs.
If you could produce examples of this, I'll try to fix them.
[snip]
Richard> The following example (and many others) give odd messages like
Richard> SIMP2F1-WILL-CONTINUE-IN
Richard> i3(2,3/2,a,x)
Richard> i3(0,1,a,x) [also says FAIL-1-IN-C-1-CASE]
Richard> i3(1,1/2,a,x) [gives "non-variable 2nd argument to diff, -x^2/a^2]
These are all left overs from the original implementation. Some have
been removed or hidden, but others have been left in as a gentle
reminder to me to fix them.
Richard> also some of the answers come out in terms of jacobi_p functions, but
Richard> diff does not know about them.
I think you need to load Barton's orthopoly to tell maxima about these
functions.
Ray