On 28 Nov., 14:11, William Hughes <wpihug...@hotmail.com> wrote: > On Nov 28, 8:35 am, WM <mueck...@rz.fh-augsburg.de> wrote: > > > On 27 Nov., 22:42, William Hughes <wpihug...@hotmail.com> wrote: > > > > Every diagonal number is in the list. > > > > Only in Wolkenmuekenheim. Outside of Wolkenmuekenheim > > > there is only one diagonal number and it is not > > > in the list. > > > How do you know, unless you have seen the last? > > You use induction to show that every entry > in the list has a final 1. So you don't have > to see an entry to know that it has a final 1 > (there is no last entry in any case). > There is a constructive proof that the > diagonal number does not have a final 1.
Use induction to show that the diagonal number cannot have more digits than every entry of the list.
There is a constructive proof that the list does not have a final entry.