In article <b1ae1877-d38d-4ec2-9526-6405c9886db5@s14g2000vbj.googlegroups.com>, WM <mueckenh@rz.fh-augsburg.de> wrote:
> On 24 Okt., 00:22, FredJeffries <fredjeffr...@gmail.com> wrote: > > On Oct 23, 12:55 pm, WM <mueck...@rz.fh-augsburg.de> wrote: > > > > > > > > > > > > > On 23 Okt., 21:45, FredJeffries <fredjeffr...@gmail.com> wrote: > > > > > > On Oct 23, 11:18 am, WM <mueck...@rz.fh-augsburg.de> wrote: > > > > > > > Cantor criterion for diverging sequences. > > > > > > I have searched G H Hardy's "Divergent Series" and find no mention of > > > > such a "Cantor Criterion". > > > > > That book is far too old. The supremum-infimum criterion is standard > > > in modern texts on set theory. The explanation in Wikipedia is > > > correct, as fas as I can see. Applying it, you can prove that the > > > sequence of sets > > > 1 > > > 1,2 > > > 1,2,3 > > > ... > > > has a limit. > > > Cantor called it omega (without knowing modern texts). > > > > I see no sets. What are you talking about?- > > Instead of the parentheses I use different lines. Easier to type.
But non-standard notation at best, which requires prior explanation to be acceptable, which prior explanation was not provided.
And are we now to interpret every line as being a set, or do you now have some special non-set notation to distinguish lines which are not sets?