On Monday, March 24, 2014 4:58:02 AM UTC+4, Richard Fateman wrote:
>
> So is every double-precision IEEE float  (except inf and NaN) convertible 
> to the
> exact rational number which it represents in the form  integer/integer.
>

It was noted in this thread several times: we are not interested
in this truism.  The problem is not with the data structure, but with 
operations.
Field properties doesn't hold for floats, it was shown for you several 
times in this
thread (CLisp example included).
 

> 2. we  can deduce from the fact that a,b are rational numbers that a+b is 
> a rational number.
>

But now, suppose a, b and c - rational numbers.  Then we can deduce:
((a + b) + c) - (a + (b + c)) is zero.   But this conclusion will be wrong 
if
we count floats as rationals. 

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