> From: Richard Fateman
>
> I just had occasion to look at the code for antid, which
> includes the locution (simplified, here)
>
> antid(..) := block( [ ..., killer, ...],
> ...
> killer(z) := ....,
> ....)
>
> Presumably the author thought he (or she) was defining a
> local function named killer. In fact, killer is just as
> global as any other function.
> It is defined the first time antid is called. And it is
> defined again each time antid is called.
>
> Probably the author should use "local".
>
> I would have preferred to send this note to the author but
> the author did not sign the file :(
>
> It would be nice if the author of this (as well as other
> contributions) were identified in the text. Also in this case
> it would be nice to explain somewhere why this program
> exists. I think it is because it can find the antiderivative
> (i.e. symbolic indefinite integral) of some expressions that
> are not currently handled by the built-in integrate command.
> I recommend that the manual and the demo provide such an explanation.
In the file archive/share/trash/antid.usg in the CVS repository we have:
The file ANTID > contains a routine for evaluating integrals of
expressions involving an arbitrary unspecified function and its
derivatives.
After BATCH'ing the file, it may be used by:
ANTIDIFF(G,X,U(X));
where G is the expression involving U(X) (U(X) arbitrary) and its
derivatives, whose integral with respect to X is desired.
The batch file also defines the functions NONZEROANDFREEOF
and LINEAR as well as ANTID. ANTID is the same as ANTIDIFF except
that it returns a list of two parts, the first part is the integrated
part of the expression and the second part of the list is the non-
integrable remainder.
A translated version of this file is available as SHARE2;ANTID
LISP.
It may be used by LOADFILE(ANTID,LISP,SHARE2).
Send complaints to BNLGHC.
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