POV-Ray : Newsgroups : povray.off-topic : Turing determination : Re: Turing determination Server Time
5 Sep 2024 11:24:22 EDT (-0400)
  Re: Turing determination  
From: Darren New
Date: 22 Jul 2009 12:29:14
Message: <4a673e5a$1@news.povray.org>
Invisible wrote:
> Now, if only it wasn't completely incomprehensible...

What part do you not understand?

 > for any non-trivial property of partial functions,

A partial function is one that isn't defined for every input value. The way 
you model that in a computation is to have the function not return, i.e., 
get stuck in an infinite loop.

 > there is no general and effective method

"general and effective" means it works for all inputs and always returns. 
(An "effective" function always returns an answer when computed.)

 > Here, a property of partial functions is called trivial if it holds for 
all partial computable functions or for none,

So if some partial functions have that property but not all, it's a 
non-trivial property.  A "trivial" property might be that it executes at 
least one computation, for example.

 > and an effective decision method is called general if it decides 
correctly for every algorithm.

That pretty much sums it up.

Or were you saying the proof is too confusing?


-- 
   Darren New, San Diego CA, USA (PST)
   "We'd like you to back-port all the changes in 2.0
    back to version 1.0."
   "We've done that already. We call it 2.0."


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