[Maxima-bugs] [ maxima-Bugs-1725951 ] unsimplified boolean

[SourceForge.net <no...@so...>]

Bugs item #1725951, was opened at 2007-05-25 21:04
Message generated for change (Comment added) made by willisbl
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1725951&group_id=4933

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: Lisp Core - Simplification
Group: None
Status: Open
Resolution: None
Priority: 4
Private: No
Submitted By: Barton Willis (willisbl)
Assigned to: Robert Dodier (robert_dodier)
Summary: unsimplified boolean

Initial Comment:
Tests 100 and 101 in rtest_boolean return expressions
that aren's simplified. Example:

(%i1) implies (a, b) := (not a) or b$
(%i2) implies (aa and bb, cc or dd);
(%o2) notaa or notbb or cc or dd
(%i3) ?print(%);
((MOR SIMP) ((MOR SIMP) ((MNOT SIMP) $AA) ((MNOT SIMP) $BB)) $CC $DD) 
(%o3) notaa or notbb or cc or dd

(%i4) expand(%,0,0);
(%o4) notaa or notbb or cc or dd
(%i5) ?print(%);
((MOR SIMP) ((MNOT SIMP) $AA) ((MNOT SIMP) $BB) $CC $DD) 
(%o5) notaa or notbb or cc or dd

%o2 and %o4 look the same, but %o2 isn't simplified.

I marked these tests as known bugs.

----------------------------------------------------------------------

>Comment By: Barton Willis (willisbl)
Date: 2009-08-12 07:04

Message:
Additional suggestions:

(1)  Delete the defmspec mnot function. 

(2)  Replace is-mnot with 

(defun is-mnot (pred)
  (take '(mnot) (mevalp pred)))

Currently, is-mnot special cases a few things before is calls
pred-reverse.


----------------------------------------------------------------------

Comment By: Barton Willis (willisbl)
Date: 2009-08-12 06:54

Message:
A putative fix:

(defmfun pred-reverse (pred)
(take '(mnot) pred))

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=104933&aid=1725951&group_id=4933