Dear All,
It seems that my correspondence with the people at Maxima has surfaced.
I purposely avoided mentioning it I regard it as embarrassing to one of
the Maxima group, who reacted to my initial enquiry by asking
Why is this a good idea? *It is not mathematically true.*
I replied with:
Alice laughed: "There's no use trying," she said; "one can't believe
impossible things." "I daresay you haven't had much practice," said the
Queen. "When I was younger, I always did it for half an hour a day. Why,
sometimes I've believed as many as six impossible things before
breakfast." ~ Lewis Carroll from Alice in Wonderland
The truth is out there, somewhere.:)
As this particular person went on to obliquely accuse me of flaming I
gave up on Maxima, which is why I am raising the matter elsewhere, but
let me quote from a draft of a book I am writing:
--------------------
The perspicacious reader may notice that in two subsections of this
chapter life is made easier by
the assumption that for the field of real numbers a/0 = 0 , despite the
comment from one person
that “It is not mathematically true.” Note that by so doing we are in
the company of Isabelle/HOL.
The author’s advice to anyone who might question this assumption is to
1. within the context of the field axioms prove that a/0 is undecidable,
reflect on the consequences
of Gödel’s Theorem, and then relax, or
2. prove that a/0 is false, then contact the author of this book and the
Isabelle group, preferably
providing dunces hats for us to wear.
--------------------
This quote gives my position and I can really only ask that you reflect,
more carefully than I believe has the person quoted above, when
considering division by zero.
Regards,
Jalaluddin
On 24/03/11 14:49 PM, Ralf Hemmecke wrote:
I don't know whether it is in fricas or not, but I have something on my
wish list for fricas - namely the option for a / 0 = 0 for the field of
real numbers, as is standard in Isabelle/HOL, and implicit for the
pseudo-inverse in linear algebra.
When you speak of "field of real numbers", which domain in FriCAS do
you mean exactly? "Float" is certainly not that domain.
Do you really mean that division by zero should give zero instead of a
division-by-zero error?
Maybe related to this?
http://comments.gmane.org/gmane.comp.mathematics.maxima.general/33656
http://www.math.utexas.edu/pipermail/maxima/2011/024297.html
Ralf
--
You received this message because you are subscribed to the Google Groups "FriCAS -
computer algebra system" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/fricas-devel?hl=en.
