Re: [tied] Re: Numerals query again

At 7:08:14 PM on Friday, November 7, 2003, Richard
Wordingham wrote:

> --- In cybalist@yahoogroups.com, Piotr Gasiorowski
> <piotr.gasiorowski@...> wrote:

>> Anyway, every natural number is special, including
>> 87492335017. The proof is by reductio ad absurdum:

Equivalently, by induction.

> <Snip>
>> Being the smallest nonspecial number makes N special.

> Does it?

> Actually I suspect there may be a fault in the schema. Is
> being special decidable?

The real problem is that 'special' is not well-defined.
It's the old heap of sand problem. If a collection of n
grains of sand constitutes a heap, surely so does a
collection of n-1 grains, but then ...

Brian