On 21 Mrz., 08:28, William Hughes <wpihug...@gmail.com> wrote: > On Mar 21, 7:54 am, WM <mueck...@rz.fh-augsburg.de> wrote: > > <snip> > > > If no line is necessary, then there is no necessary line. > > Correct, but the fact that you need to choose a line > does not mean that you need to choose a necessary line. > You can choose an unnecessary line.
Why should I do so? And what would it help. > > <snip> > > > Every not necessary line can be removed. > > by definition. > > > Why do you think there should remain unnecessary lines? > > Because you have to choose lines, and the lines > you choose must be unnecessary lines.
It is necessary that I choose unnecessary lines? Would it not be preferable to apply mathematics?
> > And if they are needed, which it the first > > unnecessary line that must remain? > > The first line depends on which lines you choose.
My question remains: What is the subset of necessary lines? is it the intersection of all sufficient lines? Unless this intersection is empty, it has to have a first element. If the intersetion is empty, then it cannot contain any line.
And this can in fact be proved: The set M of lines that are not necessary obeys:
a) 1 is in M. b) From n in M we can conclude that n+1 in M.