EDB — 0SD

Exercises

1. [0SD] Difficulty:**. Let \(A⊂ℝ\). We recall that \(D(A)\) is the derivative of \(A\) (i.e. the set of accumulation points of \(A\)). Describe a closed set \(A\) such that the sets

   \[ A, D(A),D(D(A)),D(D(D(A)))\ldots \]

   are all different.

   Solution 1

   [0SF]↺↻