On Fri, 2011-02-11 at 01:49 -0800, Simon King wrote: > Hi, > > On 11 Feb., 09:56, Simon King <simon.k...@uni-jena.de> wrote: > > Well, I had the impression that a couple of people are in favour of > > the following: > > gcd(a/b,c/d) := gcd(a,c)/lcm(b,d) > > lcm(a/b,c/d) := lcm(a,c)/gcd(b,d) > > It just occurs to me that I am incredibly stupid. > > The definition above wouldn't work at all, it isn't even well-defined. > Just replace gcd(1/4,1/6) by gcd(3/12,9/54). You obtain gcd(1,1)/ > lcm(4,6) = 1/12, but gcd(3,9)/lcm(12,54) = 1/36. > > Does anyone have a better idea? Would it be a correct definition if > one insisted on reduced fractions? > > Cheers, > Simon > That's why I was asking for an algorithm for gcd and lcm in the subdomain. I'm not sure what answer is expected. The unit (1) is correct but not by your definition, and apparently not helpful for the original poster.
Tim Daly -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
