Example of a chain without a supremum in a non Archimedean ordered field

237 Views Asked by At

I give here the example of a non-Archimedean ordered field. I know that the field is not order complete.

What is a simple example in that field of a chain without a supremum?

1

There are 1 best solutions below

0
On BEST ANSWER

It's the very thing that shows it's not Archimedean that witnesses that.

More specifically, $\Bbb N$, is such chain. If $x$ is the supremum of all the natural numbers, then $x-1$ should be smaller than a natural number $k$ and therefore $x=(x-1)+1$ should be at most $k+1$ which is a contradiction.