From: "Paul S. Penrod" <furballs@netcom.com>
Date: Thu, 23 May 1996 14:15:27 +0800
To: cypherpunks@toad.com
Subject: Re: The Crisis with Remailers
In-Reply-To: <199605222051.NAA20284@netcom21.netcom.com>
Message-ID: <Pine.3.89.9605221613.A21952-0100000@netcom>
MIME-Version: 1.0
Content-Type: text/plain




On Wed, 22 May 1996, Mike Duvos wrote:

> Perry Writes:
> 
> > Floating point systems are built to do approximate math on a very wide
> > range of number sizes. Accounting systems require exact math -- down
> > to the cent. Floats aren't suitable.
> 
> Calling floating point math "approximate" is a bit of a misnomer.  
> Floating point numbers all correspond to exact points on the real 
> number line.  The floating point number taken as the result of an 
> operation, if that result is not another floating point number, is 
> always chosen consistantly in a way which has minimum error and zero
> bias. 

If floating point is implemented properly in *both* hardware and 
software, then the claim is valid. I have seen too many instances of 
floating point support and/or emulation from people like MS and Borland 
that would scare the bejeebers out of most competent programmers

> 
> Floating point numbers can be used to do exact integer arithmetic
> quite easily.  A 48 bit mantissa can represent 14 decimal digit signed
> integers with no loss of precision, and $999,999,999,999.99 is more
> than enough magnitude for most bean counters. 
> 

Again, exact integer artimetic derived from floating point is dependant 
on how well the floating point "behaves". Mainframes dont suffer the same 
fate as some of the uP's do.

> --
>      Mike Duvos         $    PGP 2.6 Public Key available     $
>      mpd@netcom.com     $    via Finger.        7              $
> 
> 
> 

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