EDB — 0SQ

Exercises

1. [0SQ] Prerequisites:[0H7]↺↻, [0H9]↺↻.For each $A\subseteq {ℝ}^n$ closed non-empty set, there exists $B\subseteq A$ such that $A=\partial B$.

   In which cases does there exist such a $B$ that is countable?

   In which cases does there exist such a $B$ that is closed?

   Solution 1

   [0SR]↺↻

   See also [0MH]↺↻.

   [ [0ST]↺↻]