On 8 Mrz., 10:41, Virgil <vir...@ligriv.com> wrote:
> > A set of natural numbers, finite or infinite, without a first element > > is not object of mathematics. > > > > > Name the first line. > > > > Which first line? There are infinitely many possible first lines. > > > In fact EVERY line is a first line of some such set. > > > Name at least one line that is not obviously irrelevant for the task. > > Since any line can be the first line of a suitable set of lines, each > line is relevant, but also unnecessary.
Each line is relevant but also irrelevant. A nice confession.
Learn: In mathematics, we have sets of natural numbers without last elements. A set of natural numbers without a first element is not object of mathematics.