[Haskell-cafe] Re: US Homeland Security program language security risks

[Cristian Baboi]

On Sun, 06 Jan 2008 17:19:31 +0200, Daniel Fischer  
<daniel.is.fischer at web.de> wrote:

> Am Sonntag, 6. Januar 2008 15:54 schrieb Achim Schneider:
>> Daniel Fischer <daniel.is.fischer at web.de> wrote:
>> > Am Sonntag, 6. Januar 2008 15:18 schrieb Andrew Coppin:
>> > > Daniel Fischer wrote:
>> > > > Just because I don't know:
>> > > > what bugs would be possible in a language having only the
>> > > > instruction return ()
>> > >
>> > > Bug #1: You cannot write any nontrivial programs. ;-)
>> >
>> > That's not a bug, that's a feature.
>>
>> That's an interesting task: Design a non-touring complete,
>> restricted language in which every expression is decidable, without
>> making the language unusable for usual programming problems.

> I'm not a logician, but didn't Gödel prove that you couldn't express the
> (full) arithmetic of natural numbers in such a language?
> Of course it might be possible to express a sufficiently interesting  
> part of
> it, but I should be surprised.

Neither do I, but if you have non turing algorithms, maybe you could do it.