more three problems...



In article 
<eb9c4b9a0705051636q1c75884cr24a18fbadf1ed550 at mail.gmail.com>,
 "Robert Dodier" <robert.dodier at gmail.com> wrote:

> On 5/5/07, Rainer Joswig <joswig at lisp.de> wrote:
> 
> > > Sorry, my mistake. I asked the wrong question. I meant to say,
> > > What does (INTEGER-DECODE-FLOAT 5.2d20) return?
> 
> > MAXIMA 19 > (INTEGER-DECODE-FLOAT 5.2d20)
> > 7934570312500000
> > 16
> > 1
> 
> OK, that seems like the correct result. At this point I give up.
> 
> I'm still interested to know why 7.000000000000013E19 yields a
> test failure compared to 7.0E19.
> 
> Thanks for your help,
> Robert

It boils down to this:

LispWorks 5

CL-USER 6 > (expt 1.0d+20 2)
1.0000000000000016E40

CL-USER 7 > (*  1.0d+20  1.0d+20)
1.0E40

most Lisp systems I tried are giving the same result
for both forms.

Regards,

Rainer Joswig

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