Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: Determinism is hard & not the only thing on our plate...



In general, the problem of providing form-invariant enclosure is NP-hard, see our paper

http://www.cs.utep.edu/vladik/2011/tr11-35.pdf

that we submitted recently to Reliable Computing

________________________________________
From: stds-1788@xxxxxxxx [stds-1788@xxxxxxxx] On Behalf Of N.M. Maclaren [nmm1@xxxxxxxxx]
Sent: Thursday, August 04, 2011 6:07 AM
To: Dan Zuras Intervals
Cc: stds-1788@xxxxxxxxxxxxxxxxx
Subject: Re: Determinism is hard & not the only thing on our plate...

On Aug 4 2011, Dan Zuras Intervals wrote:
>
>       Nick, I don't want to go tit for tat with you in an open
>       forum in the hope that one of us will change our mind.
>       That does nobody any good & pisses off our readers.
>
>       Determinism is hard.  You have to pay a price for it.
>       Things can be done to mediate the problem of parallelism
>       but it is true that performance is part of the cost.
>
>       This does not mean we should not offer our users the means
>       to compute deterministically.  We should.  We should also
>       offer them other things.

It is clear that we are still not communicating.  I am asserting not
just that it is hard and conflicts with performance, but that it is
actually infeasible.  Some of the infeasibilities that I am claiming
are mathematical or are statements about what language standards say,
and therefore subject to proof or disproof.  In those cases, there
are two possibilities:

    I am wrong, and therefore my statements can be disproved.  In this
case, I should be corrected, and then I should just shut up.

    I am right, and therefore you are proposing an infeasible project.
In this case, following the path you propose will lead to 1788 failing,
whether or not it is completed.


Regards,
Nick Maclaren.