Re: Gcd in Z[I]

[Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>]

On Thu, Nov 01, 2007 at 12:53:10PM +0100, Olivier Ramare wrote:
> Dear all,
> 
>   I simply would like to check that I'm not
> doing any mistake: gcd answers the gcd in Z[I]
> when the arguments are in Z[I], correct?

Yes. Also since the gcd of two integers is the same computed over Z or
Z[i], this is safe, as opposed to factor:

? factor(x^2+4+0*I)
%13 =
[x - 2*I 1]

[x + 2*I 1]

? factor(x^2+4)
%14 =
[x^2 + 4 1]

Cheers,
Bill.