[5753] in cryptography@c2.net mail archive
Re: having source code for your CPU chip -- NOT
daemon@ATHENA.MIT.EDU (Eli Brandt)
Fri Sep 24 12:31:16 1999
Message-Id: <199909241618.JAA19232@blacklodge.c2.net>
To: crypto list <cryptography@c2.net>
Date: Fri, 24 Sep 1999 12:17:25 -0400 (EDT)
From: Eli Brandt <eli@v.gp.cs.cmu.edu>
In-Reply-To: <v04210100b4109e8a01f2@[24.218.56.100]> from "Arnold Reinhold" at Sep 24, 99 09:38:54 am
Reply-To: eli+@cs.cmu.edu
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Arnold Reinhold wrote:
> >Arnold Reinhold wrote:
> > > Perry, if you really believe that the question of whether a given
> > > lump of object code contains a Thompson Trap is formally undecidable
[...]
> I am not asking about the class of all Turing machines, just one
> particular lump of object code OC that happens to be a compiler--say
> the C++ compiler on the Red Hat 6.0 distribution.
I must admit, even though you said "whether a given lump" I assumed
the decision procedure was supposed to exist uniformly over lumps.
If you swap the quantifiers, sure, for any program there exists a
decision procedure -- either the decider that always says "yes" or the
one that always says "no". (Okay, I see why you don't find theory
relevant.)
--
Eli Brandt | eli+@cs.cmu.edu | http://www.cs.cmu.edu/~eli/
