Re: Mathematica "Reduce" function

[Pedro Fortuny Ayuso <fortunypedro@uniovi.es>]

Thanks to all.

My specific problem is trying to solve equations like

6x^2 + 12y^2 +20z^2 = 0

over Z/(2^k)Z. That is, finding the points of that surface
over that ring.

Bill's reply of counting

length([[x,y,z]|x<-[0..2^k-1];y<-[0..2^k-1];z<-[0..2^k-1],6*x^2+12*y^2+20*z^2==0])

is the fastest but it ***looks like*** a lot slower than
Mathematica (but please notice I am working on a system
with pari/gp and my colleague on a different one with Mathematica,
so that it may have nothing to do with pari/Mathematica).

I know nothing about number theory, I just can guess what
'solving on the p-adics and then lifting' might mean but
am not quite ready to implement it.

Thanks again,


Pedro.



-- 
Pedro Fortuny Ayuso
http://pfortuny.net


EPIG, Campus de Viesques, Gijon
Dpto. de Matematicas
Universidad de Oviedo