| John Cremona (Maths) on Wed, 15 Jul 1998 15:39:52 +0100 |
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| Re: Query about factorpadic |
Nigel is wrong: when x is odd, the valuation of 2x+2 can be anything positive, even infinite (x=-1). For a quadratic there cannot be any distinction between lifting a root and lifting a factorization. It seems that factorpadic(f,p,r) is not the same as factoring f mod p^r in (Z/p^r)[X], but rather the mod p^r approximation to the ACTUAL p-adic factorization. As its name suggests. For example, factorpadic(x^2+2^10,2,r) gives one quadratic factor even for r=1. I think that this discussion should probably not be going on via the pari users' list...? John -- John Cremona University of Exeter Department of Mathematics North Park Road Exeter EX4 4QE UK Tel.: +44-1392-263974 (Office) +44-1392-210758 (Home) Fax: +44-1392-263997 email: cremona@maths.exeter.ac.uk