Prev: Welsh's Matroid Theory book is back in print
Next: Give me ONE digit position of any real that isn't computable up to that digit position!
From: hagman on 5 Jun 2010 07:40 On 5 Jun., 05:11, Pollux <frank.ast...(a)gmail.com> wrote: > I like that bijection. I had started thinking about multiplying a and b in a + bi to get a single real (that would be one half of the bijection, I needed something eld for the other half), but of course, this naive multiplication wouldn't work (z1 = a1 + b1i and z2 = b1 + a1i would map to the same real :-( ). Interleaving is going to work in both directions though. Great! > > Thanks for your help! > > Pollux Your next task is to find a bijection that is continuous in one of the two directions (it can't be i nboth directions) :) hagman
From: A N Niel on 5 Jun 2010 07:56
In article <cfd67c23-7633-4968-8e3e-25395b72e6a6(a)x21g2000yqa.googlegroups.com>, hagman <google(a)von-eitzen.de> wrote: > On 5 Jun., 05:11, Pollux <frank.ast...(a)gmail.com> wrote: > > I like that bijection. I had started thinking about multiplying a and b in > > a + bi to get a single real (that would be one half of the bijection, I > > needed something eld for the other half), but of course, this naive > > multiplication wouldn't work (z1 = a1 + b1i and z2 = b1 + a1i would map to > > the same real :-( ). Interleaving is going to work in both directions > > though. Great! > > > > Thanks for your help! > > > > Pollux > > Your next task is to find a bijection that is continuous in one of the > two directions (it can't be i nboth directions) :) > > hagman Why suggest impossible tasks to a beginner? |