On 21 Mai, 10:03, William Elliot <
ma...@panix.com> wrote:
> On Sun, 20 May 2012, WM wrote:
> > The set of all finite paths (from the root-node to any other node)
> > in the complete infinite Binary Tree is countable. Therefore the
> > complete infinite Binary Tree has countably many paths that can be
> > identified by nodes.
> > It is impossible to identify an infinite path by nodes, because
> > 1) every node belongs to a finite path, and
>
> Every node is within infinitely many finite paths.
>
> > 2) there is no identification unless it has been finished.
>
> Every path in the binary can be described by a infinite binary
> sequence.
Please describe only one path by an infinite binary sequence.
>
> If you always wait to get to the end of an infinite sequence,
> you'll accomplish nothing.
It is impossible to send or understand messages without end.
>
> > Therefore an infinite path can only be identified by a finite
> > expression like "always turn left", or "0.111...", or "the path which
> > represents 1/pi", or simply "1/3". However, the set of finite
> > expressions has countable cardinality.
>
> Some infinite paths are computable, expressible in some formal language,
> as a finite statement.
Every path that can spring off from a Cantor list has a finite
definition.
>
> > Therefore the set of all paths in the complete infinite Binary Tree
> > has countable cardinality.
>
> The set of all computable infinite paths is countable.
> Almost all infinite paths aren't computable.
Better say, they do not exist. They are of no value for mathematics,
because nobody could use them. They cannot result from a Cantor list
and they cannot be useful for any mathematical problem.
To insist on unknowable and unusable entities is matheology.
>
> Apparently you're taking a constructionist view.
> From that limited view, and only from that limited
> view, you notions hold; your notions hold to a
> minority of mathematicians.
No. I avoid believing in items that cannot be part of mathematics
(that is a language that serves for communication and computation).
>
> On the other hand, insisting to get to the end a sequence
> indicates you hold a finistic view of mathematics - a view
> held by a tiny minority of mathematicians.
Nobody can get to the end of something that has no end.
Therefore everything that can appear in mathematics need to have a
finite definition.
You (and anybody else either) are not capable of naming, defining,
using one of your asserted uncomputable real numbers. Further they are
not useful to mainain Cantor's view, because every diagonal number
constructed from a Cantor-list is computable. A number does not exist
by itself. A number is a definition. Why do you believe in undefinable
definitions?
Regards, WM