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-   -   Define a Prime (https://www.mersenneforum.org/showthread.php?t=7197)

davar55 2007-02-24 17:45

Define a Prime
 
Can you define prime numbers over the non-negative
integers without any explicit reference to 0 or 1 or 2
or any other specific integer?

Orgasmic Troll 2007-02-24 17:52

[QUOTE=davar55;99304]Can you define prime numbers over the non-negative
integers without any explicit reference to 0 or 1 or 2
or any other specific integer?[/QUOTE]

non-negative integers that are only divisible by themselves and the units in the ring of integers

akruppa 2007-02-24 17:52

An integer so that any product equal to the integer must involve the integer itself, units, and nothing else.

Alex

xilman 2007-02-24 18:00

[QUOTE=davar55;99304]Can you define prime numbers over the non-negative
integers without any explicit reference to 0 or 1 or 2
or any other specific integer?[/QUOTE]

[spoiler]Let (p,q) be non-negative integers such that N=p*q and p>q

If for all (p,q) p=N, then N is prime.
[/spoiler]

Pau

philmoore 2007-02-24 20:19

Here's another try:

[spoiler]A positive integer p is prime if and only if the only solutions to the equations p = a*b = c*d occur when a is not equal to b and a = c and b = d or a = d and b = c. (I almost said that the equation p = a*b has exactly two solutions (a,b) where a and b are positive integers, but then realized that I was violating the terms of the problem!)[/spoiler]

Mini-Geek 2007-02-24 22:23

A prime number (or a prime) is a natural number that has exactly two (distinct) natural number divisors, which are (4 - 3) and the prime number itself.
:grin: Hooray for loopholes! :grin:

akruppa 2007-02-24 23:04

[QUOTE=Mini-Geek;99329]that has exactly [B]two[/B] [/QUOTE]

Rule violation. Five yards penalty.

Alex

xilman 2007-02-24 23:34

[QUOTE=TravisT;99307]non-negative integers that are only divisible by themselves and the units in the ring of integers[/QUOTE]

Counter-example.

3 is a non-negative integer

3 is divisible by itself --- meets your definition

3 is divisible by 1, a unit in the ring of integers --- meets your definition

3 is divisible by -1, a unit in the ring of integers --- meets your definition

-3 is an element of the ring of integers

3 is divisible by -3


Therefore, according to your definition, 3 is not a prime.



Paul

akruppa 2007-02-24 23:52

Same problem with my definition. Let's try

An integer so that any product equal to the integer must involve the integer itself or one of its associates, any number of units, and nothing else.

Alex

Mini-Geek 2007-02-25 00:35

[quote=akruppa;99330]Rule violation. Five yards penalty.

Alex[/quote]Ok, fine, here's the updated version:

A prime number (or a prime) is a natural number that has exactly (5 - 3) (distinct) natural number divisors, which are (4 - 3) and the prime number itself.
:grin: Hooray for loopholes! :grin:

XYYXF 2007-02-25 01:29

One may try to invent something analytical from
[url]http://mathworld.wolfram.com/LandausFormula.html[/url]

:-)


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