If x and box(x) test 'alike', then presumably you'll get things like
x-box(x) => 0. But isn't part of the point of box precisely to block
such things?
-s
On 2010-06-06, Richard Fateman <fateman at cs.berkeley.edu> wrote:
> Stavros Macrakis wrote:
>> On Sun, Jun 6, 2010 at 15:21, R Fateman <fateman at cs.berkeley.edu
>> <mailto:fateman at cs.berkeley.edu>> wrote:
>>
>> ...now consider (setf n '((mbox simp)((mplus simp) $a $b)))
>> (setf m (cadr n))
>> ...
>> (great n m) is T
>> (great m n) is also T
>>
>> this is apparently not an error, or at least it works the same in
>> 5.17 maxima and 5.21 maxima.
>> the ordering of some expression E and box(E) should be the
>> same...
>>
>>
>> Though undoubtedly (X<E iff X<box(E)) and (E<X iff box(E)<X) when X is
>> not a box-expression, that does not mean that E<box(E) and box(E)<E
>> should both be TRUE. If they are, the canonical (simplified) form of
>> (e.g.) x+box(x) is not well-defined.
> yep.
>> I would guess that there are other parts of Maxima besides simp-%sin
>> that can break if E<box(E) and box(E)<E.
> except that it seems the system works with an older simp-%sin...
> I agree in principle with Stavros. but maybe then (alike E ((mbox )
> E) should return T.
>
>
> Here is a thought, which I think I've expressed previously,
> that having great() check for mbox so much is uncomfortable, since it
> almost never is there.
> maybe we can move this out of the main loop of the simplifier (i.e. in
> great or in alike).
>
> One possibility is to put the "box" info somewhere else, not exactly in
> the expression tree.
> e.g. ((mplus simp BOX BOXLABEL) $a $b).
> So this could be noticed by the display program, but ignored by great().
>
> Hazards: what to do with just a symbol, e.g. $A. ((mplus simp
> BOX BOXLABEL) $A 0) ???
> Also ((mplus) $X ((mplus simp BOX) $X $Y) ) would try to make
> 2*x+y... where's the box?
>
> Back to work..
>
> RJF
>
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima
>