> I define "have" to mean "the bit pattern for an IEEE floating 
> point (FP) negative zero exists in an array of FP in J".  

The interpreter knows what arrays it has;
The interpreter can not do anything without
allocating memory;
The interpreter allocates memory in a single place;
In the single place, apply the existing minus_zero
eradicator to every array.



----- Original Message -----
From: Dan Bron <[EMAIL PROTECTED]>
Date: Monday, April 23, 2007 10:29 am
Subject: Re: [Jgeneral] zero

> RM = Raul Miller, DB = me, RH = Roger Hui
> 
> DB>           %floating_zero
> DB>        _
> 
> RM>  But % is not fixed.
> 
> I only included  %  to demonstrate that I'd successfully created a 
> negative zero.  The point of my message was the line above this.
> 
> RH>  You can not win. 
> 
> Au contraire.  It is you who are doomed.
> 
> RH>  You have to use primitives. 
> 
> You have to use memory.
> 
> RH>  If all the primitives take care to 
> RH>  eradicate minus zero, 
> 
> That was exactly the point; there are an infinite number of ways 
> for me to manipulate memory to create a negative zero.  I could 
> even do it from outside of J.
> 
> Our debate hinges on the definition of "have", used in the sentence:
> 
> DB>  J will still have a negative zero 
> 
> I define "have" to mean "the bit pattern for an IEEE floating 
> point (FP) negative zero exists in an array of FP in J".  
> 
> You appear to define it as "any Z that can be distinguised from  0 
> using  J  primitives,  such that y = y+Z  where  -. y e. 0,Z  ".
> 
> So our discussion is moot.
> 
> RH>  I estimate that it would take me less than an hour 
> RH>  to build a version of J that can eradicate
> RH>  minus_zero, if I really wanted to.
> 
> I estimate it would take me less than an hour to find a relevant 
> bug in it, if I really wanted to.
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