Skip to main content
edited tags
Link
Andrés E. Caicedo
  • 32.5k
  • 5
  • 133
  • 240
Post Closed as "Not suitable for this site" by Emil Jeřábek, user44191, Gerry Myerson, ARG, Andreas Blass
Source Link

Real number which is different from all rationals

By diagonalization, it is possible to construct a real number $r \in [0,1]$ such that for every rational $q \in [0,1]$, there exists an index $i \in \mathbb{N}$ such that $r_i \neq q_i$ (where $x_i$ is the $i$'ith digit in $x$).

Can we make a stronger claim, and construct a real number $r \in [0,1]$ such that for every rational $q \in [0,1]$ there exists an index $i \in \mathbb{N}$ such that for every $j \geq i$, $r_j \neq q_j$?