RE "problem" with Euclid's proof of the Infinitude of Primes
----- Original Message -----
> (1). The prime numbers are the numbers p1,p2,...,pn,... of set S.
> Suppose S is finite [supposition].
> (2). If S is finite then: p1,p2,...,pn is the complete series set, so that
pn is the largest prime.
> (3). Form W+1 = (p1xp2x,...,xpn) + 1.
> W+1 is not in the set S so it is not prime.
> W+1 is not divisible by any of primes in S_P so it
> is prime.
> Reverse supposition and primes are infinite.
You are right when you say W+1 is not in the set, but are wrong when you say
it has to be prime. You are missing one case:
If W+1 is not divisible by any prime in S then automatically you have to
deduce that S is not the set of all primes: then you have to admit that any
number bigger than pn can be prime as well; so W+1 is either prime or
divisible by primes between pn and W+1.