On May 13, 11:48 pm, Virgil <vir...@ligriv.com> wrote: > In article > <6bb5684c-3fc0-48a1-8de5-cc51f7478...@a15g2000pbu.googlegroups.com>, > > > > > > > > > > mike3 <mike4...@yahoo.com> wrote: > > On May 13, 8:17 pm, Virgil <vir...@ligriv.com> wrote: > > > In article > > > <bf23b508-9d6c-459b-b797-5022f1dd0...@tz3g2000pbb.googlegroups.com>, > > > > mike3 <mike4...@yahoo.com> wrote: > > > > Hi. > > > > > I'm curious about this. The "Archimedean property" for an _ordered_ > > > > field F means that given any positive elements a and b in F, with a < > > > > b, then there exists a natural number n such that na < b. > > > > Not quite as stated above. > > > > Given 0 < a < b there must be some natural n such that na > b. > > > > But if a is negative, one will have na < b for all naturals n. > > > > The standard ordered field of reals and all of of its subfields have > > > the property, but fields with infinitesimal elements do not. > > > -- > > > Correct. I made a mistake/typo: it should be "na > b". > > And it should be only for a > 0 and b > 0. > --
I already mentioned that a and b should be "positive elements" (i.e. greater than 0).