On Aug 24, 7:19 am, mabshoff <[EMAIL PROTECTED]
dortmund.de> wrote:
> On Aug 24, 4:40 am, Kevin McGown <[EMAIL PROTECTED]> wrote:
>
>
>
> > William,
>
> > In SAGE 2.8 it seems there is a problem with the is_principal method
> > for fractional ideals in a number field. In the code below I create
> > the same ideal in two different ways and obtain two different answers
> > from is_principal (True and False).
>
> > K = QuadraticField(-119,'a')
> > P2 = K.ideal([2]).factor()[0][0]
> > I = P2^5
> > a = K.0
> > J = K.ideal([1/2*a+3/2])
> > I==J
> > I.is_principal()
> > J.is_principal()
>
> Hello Kevin,
>
> with Sage 2.8.2 I get:
>
> sage: K = QuadraticField(-119,'a')
> sage: P2 = K.ideal([2]).factor()[0][0]
> sage: I = P2^5
> sage: a = K.0
> sage: J = K.ideal([1/2*a+3/2])
> sage: I==J
> True
>
> So, could you please test after you upgrade Sage if the problem is
> gone there, too?
>
Sorry Kevin,
I am an idiot and in need of sleep. You are right:
sage: I.is_principal()
False
sage: J.is_principal()
True
I files this as ticket #487 and attached your suggested fix.
Cheers,
Michael
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