On Fri, 6 May 2011 15:22:25 -0700 (PDT)
tvn <nguyenthanh...@gmail.com> wrote:
> given a list of equality expressions, is there a way to remove all the
> members that can be inferred by others in the list so that the final
> list contains only independent expressions and they imply all the ones
> that were removed.
>
> For example
>
> [x == 2, x^2 = 4] => [x == 2]
>
> ([x*x-y*y==0,x-y==0,x*x-y*y==0,2*x*y-2*y*y==0] => [-x + y == 0]
>
>
>
> I tried to use Grobner basis
>
> Q = PolynomialRing(QQ,[x,y,z ...])
> result = (Q*input_list).groebner_basis()
>
> but it's not the right approach for this because
>
> [a*y - b == 0,a*r - a*x + b*q == 0,q*y + r - x == 0] => [a*y - b ==
> 0, q*y + r - x == 0, -a*r + a*x - b*q == 0] even though a*r - a*x +
> b*q == 0 can be implied from the other two.
>
>
> Any suggestion ?
You can try qepcad, see:
sage: qepcad?
You will need to install the experimental package before you can use
any of it.
sage: install_package('qepcad')
Cheers,
Burcin
--
To post to this group, send email to sage-support@googlegroups.com
To unsubscribe from this group, send email to
sage-support+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/sage-support
URL: http://www.sagemath.org
