Subject: possible bug with integration of unit_step
From: Dieter Kaiser
Date: Wed, 17 Dec 2008 22:41:02 +0100
Am Mittwoch, den 17.12.2008, 08:33 -0700 schrieb Robert Dodier:
> Barton,
>
> I'm guessing something got broken recently (around Dec 6).
> I have builds dated Dec 5 w/ cvs Maxima + GCL and SBCL,
> and those do not show the bug. But builds dated Dec 7 w/
> CMUCL and Clisp, and Dec 12 w/ ECL, do show it.
> I 'm pretty sure 5.17.1 (branched Dec 1) does not.
I have introduced the problem. The error is in the function
facsum-exponent. Applied to any function the result is ((mtimes) $x).
(%i16) :lisp (setq $form ($read))
unit_step(x);
(($UNIT_STEP SIMP) $X)
(%i16) :lisp (facsum-exponent form)
((MTIMES) $X)
The last result should be (($unit_step) $x) and not ((mtimes) $x). This
wrong result matches the pattern m2-exp-type-2 and is integrated.
I am looking at the problem.
Dieter Kaiser