Some things are tough to follow whether in the math or in the
computer science.
Your question is quite vague, unfortunately, so one can only
guess that you are asking why we cannot stop in the "middle"
of a Lucas-Lehmer test. The essential answer is that we
know a property of particular terms in the sequence 4, 14, 192...
given recursively by squaring and subtracting 2. That propery
is that Q=(2^p)-1 is prime iff the p-1 term is divisible by Q.
We have no other information -- so we cannot stop in the middle.
Does this help at all?
Joth
----- Original Message -----
From: Ian L McLoughlin <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, October 02, 1999 8:17 PM
Subject: Mersenne: Why test to (completion?)
> Sorry
> But.
> Why do primality tests run to the full value of the integer....For any
> iteration surely if an exponent is found within the test it should be
> reported and the program aborted?.....Not being a maths buff...
> Perhaps I should not be on this list...
> p.s. The Proth prime site was even more confusing, did not tell me what a
> Proth prime is, but totally confused me with Cunninghams, Sophie Primes et
> al...( I have heard of her, though 18/19th Century geezer...Not in the
same
> league as Galois though....
> I am beginning to think that maths people talk to deep or...to simply,
where
> is the middle ?
> Sorry!
> Keep it simple stupid for us mere mortals!
> Ian McLoughlin, Chematek U.K.
>
> Tel/Fax : +44(0)1904 679906
> Mobile : +44(0)7801 823421
> Website: www.chematekuk.co.uk
>
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