check if object is number

[Steven Bethard]

Michael Spencer wrote:
> Christos TZOTZIOY Georgiou wrote:
> 
>> On Sat, 12 Feb 2005 16:01:26 -0800, rumours say that Michael Spencer
>> <mahs at telcopartners.com> might have written:
>>
>>> OK - then my entry is:
>>>     assert obj+1 >= 1
>>> :-)
>>
>> So -1 is not a number.
> 
> At least not a legal one for Steven's function as I understood it

No, -1 is still a "number" for my particular case.

Basically, I want "numbers" to be valid upper bounds to an increasing 
sequence of integers.  This means that "numbers" must be comparable to 
integers and must behave properly as upper bounds to integers.  More 
formally:

If n is a "number" (in my particular sense), then there exists an 
integer i such that i > n, and for all integers i such that i > n and 
for all positive integers x, i + x > n.

STeVe