---- Original message ----
>Date: Sat, 04 Mar 2006 00:19:33 +0100
>From: Jean-Sibastien Bour <[EMAIL PROTECTED]>  
>Subject: Re: what is next?  3.10 or 4.0???  
>To: misc@openbsd.org
>
>Reid Nichol a icrit :
>> --- Jean-So?=bastien Bour <[EMAIL PROTECTED]> wrote:
>>   
>>> Matthias Kilian a icrit :
>>>     
>>>> a) 4 is the first non-prime, at least according to factor(6).
>>>>   
>>>>       
>>> No, it is 1 :)
>>> Explanation : a prime number can only be divided by two different 
>>> numbers : 1 and itself. 1 can only be divided by one number,
>>> therefore it is not prime.
>>>     
>>
>> Wrong.
>>
>> You got the definition of what a prime number is wrong.  A prime number
>> is defined as a positive integer greater than one which has positive
>> divisors 1 and itself, only.
>>
>> Please note that using your definition 7 is not prime because -7, -1, 1
>> and 7 all divide 7.
>>
>> I suggest at least looking into elementary number theory before making
>> such statements again.
>> Tired of spam?  Yahoo! Mail has the best spam protection around 
>> http://mail.yahoo.com 
>>
>>
>>   
>No no not wrong, indeed I didn't talk about being positive. But being 
>prime is being positive (should have said it I agree) and have EXACTLY 
>TWO different divisors.  And if 1 were prime you wouldn't have only one 
>unique decomposition in prime numbers ;) (for exemple, is 45 = 3x3x5 or 
>1x3x3x5 or 1x1x1x3x3x5 or... ?) It would crush many things down about 
>arithmetics.

nobody here is arguing that 1 IS prime. more transparently, the ideal generated
by (1) is NOT a prime ideal (it's the whole ring). also, a factorization in a
UFD is only unique up to multiplication by a unit. i think 1 is a unit, i'm not
sure... :P

>
>Luckily I have learnt some things during my two year special scientific 
>studies (heard about "Classes priparatoires" in France ?) and this is 
>one of those.
>

i assume you also learned about throwing out irrelevant egomaniacal chaff
whenever you're feeling insecure about your mathematical inabilities in your
"advanced" courses. how french, how academic!

Reply via email to