Martin RUBEY wrote:
> A quick reply, for a better reply I need to know some more things:
>
> 1. Question:
> It seems that it is perfectly alright for $rat to put *anything* on the
> DISREP property of a genvar symbol, discarding its previous value?
>
> Is this really true?
I don't know. I would not expect $rat to do anything other than what
the corresponding kernel from varlist
>
> 2. Question:
> How is the varlist genvar genvar-plist correspondence supposed to work?
the genvar list should be at least as long as the varlist. The first n
corresponding
items in the ((mrat ....)..) header should define the correspondence.
>
> I see lots of functions (in hayat.lisp) putting stuff on the DISREP
> property of genvars, and rat3e/pdisrep reads this property.
I don't know why this disrep property is used outside the $ratdisrep
program.
>
> In fact, it is ($ratdisrep ($rat e *var*)) at the very beginning of
> fpolysum (which is in turn called by maxima-substitute, taylor2, and so
> on) which puts a $L on the DISREP property and makes varlist, genvar and
> the DISREP properties look as follows:
>
> (I made a list (varlist (genv1 DISREP-prop1) (genv2 DISREP-prop2) ...))
>
> ("fpolysum"
> ($D ((%SUM SIMP)
> ((MTIMES SIMP) ((%SUM SIMP) ((MEXPT SIMP) $L $K) $L 1 $
> ((MEXPT SIMP) $M $K))
> $K 1 $INF)
> $M)
> ((#:D21809 $L) (#:|'SUM(('SUM(L^K,L,1,D))*M^K,K,1,INF)21808|
.... this is odd. it has made a gensym with a really funny name. I guess
.... that is a good reminder and harmless. Except it seems to have done
it wrong!
> (#:M21808 $M)))
>
> I find this very strange: following the varlist / genvar correspondence, I
> believed that #:D21809 should correspond to $L, but ratdisrepd will read
> $L, it doesn't read the varlist...
>
> In fact, I don't think this is a bug. To judge, I would have to know how
> disreping works: It does not seem that the varlist is read...
>
> (I think I have to give up)
> Thanks anyway, Martin
>
> ----------------------------------------------------------
>
>
>>also note that there are sticky parts involving
>>rational forms where the kernels are subtlely dependent
>>
>>e.g. exp(x), exp(y), exp((x+y)/2) should not have 3 gensyms.
>
>
> what do you mean with "sticky parts"?
>
> _______________________________________________
> Maxima mailing list
> Maxima@www.math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima