Hi Nils,

I actually fixed this bug already -- I think in response to a bug
report from Thea a while ago.  Unfortunately, I haven't
released a new version of SAGE with the fix.  I will be releasing
a new version of SAGE within the next few days, hopefully.
Do you want me to try to extract out a patch (I think I posted
one in an email to Thea).

By the way, what do you think of:
   https://sage.math.washington.edu:8102/

William

On 6/21/07, Nils Bruin <[EMAIL PROTECTED]> wrote:
>
> The bug below is actually a blocker for certain linear algebra
> problems over Z/dZ. From what I can see,
> apparently, elements of Integers(D) can be of one of IntegerMod_int,
> IntegerMod_int64 or IntegerMod_gmp
> and apparently they get mixed in the same parent. Coercion problems
> ensue.
> Unfortunately, resolving the problem is way beyond me. Would it be
> possible for someone who knows about the architecture to look into
> this problem?
>
> http://www.sagemath.org:9002/sage_trac/ticket/387
>
> Example:
>
> A=matrix([(70, 49, -20, -34, 57), (-49, -14, 95, 43, 85), (-95, -63,
> 68, 52, 12), (11,-16, -50, 43, 76), (-55, 83, 55, 40, -14)])
> D=A.determinant()
> R=Integers(D)
> MD=MatrixSpace(R,A.nrows(),A.ncols())
> AD=MD(A)
> # You would expect elements of R and entries of AD to be of exactly
> the same type.
> # this is not the case, however:
> print parent(AD.row(1)[1])
> print parent(R(3))
> # Indeed, the types of these are not the same:
> print type(AD.row(1)[1])
> print type(R(3))
> # and this has consequences: You'd expect the following to work, but
> it gives an error:
> R(3)*AD.row(1)
>
>
> >
>


-- 
William Stein
Associate Professor of Mathematics
University of Washington
http://www.williamstein.org

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