On Mar 13, 11:05 pm, WM <mueck...@rz.fh-augsburg.de> wrote: > On 13 Mrz., 22:41, William Hughes <wpihug...@gmail.com> wrote: > > > Let J be a set of the lines of L with no > > findable last line. At least two lines > > belong to J. Are any lines of J necessary? > > Remove all lines. > Can any numbers remain in the list? No. > Therefore at least one line must remain in the list. > > We do not know which it is, but it is more than no line. > In other words, it is necessary, that one line remains.
However, it is not necessary that any one particular line remain. So while it is necessary that the set J contain one line, there is no particular line l that is necessary.
> From the construction we know, that all numbers, that are in two > lines, are in one line.
True. And indeed all numbers are in two lines. However, not the same two lines.
> Therefore your claim, that more than two lines > must remain in the list, is contradicted.
False. This would only follow if all numbers were in the same two lines.