[lojban] Re: [lojban-beginners] A challenge for computer science/programming geeks: The LLG wants to give you $500!

[Robin Lee Powell <rlpowell@digitalkingdom.org>]

On Thu, Oct 30, 2008 at 12:00:35PM -0800, Stephen Pollei wrote:
> On 10/30/08, Robin Lee Powell <rlpowell@digitalkingdom.org> wrote:
> > On Thu, Oct 30, 2008 at 11:21:45AM -0800, Stephen Pollei wrote:
> >  > On 10/28/08, Robin Lee Powell <rlpowell@digitalkingdom.org> wrote:
> 
> >
> > You're wrong, I'm afraid.
> >
> >  http://en.wikipedia.org/wiki/Parsing_expression_grammar#Examples
> >
> >  Look for "The following parsing expression grammar describes the
> >  classic non-context-free language".
>
>     S => &(A !b) a+ B !c
>     A => a A? b
>     B => b B? c
>
> would will my transformations become
>
>     S =>  a+ B
>     A => a A? b
>     B => b B? c
>
> all since I specified that ?, *, and + would be non greedy than this
> cfg grammar would match whatever that peg grammar matches, only
> problem is that it would over match, and would possible have multiple
> matches.

That's not even remotely the same language.  For one thing, there's
no way to get to A, so it's actually:

S => a+ B
B => b B? c

which is just a^mb^nc^n, which is a completely different language.
You may already understand this, and that's fine, I just want there
to be no confusion: a language that is as close to Lojban as that is
to a^nb^nc^n is of no use to us, and we won't pay out for it.

-Robin

-- 
They say:  "The first AIs will be built by the military as weapons."
And I'm thinking:  "Does it even occur to you to try for something
other than the default outcome?" -- http://shorl.com/tydruhedufogre
http://www.digitalkingdom.org/~rlpowell/ *** http://www.lojban.org/


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