Theorem: Nested Closed Subset Theorem

Let \(X\) be a complete metric space, and let $$A_0\supset A_1\supset A_2\supset A_3\supset \ldots$$ be a sequence of non-empty subsets of \(X\) with diameters converging against \(0\), formally $$\lim_{k\to\infty}\operatorname{diam}(A_k)=0.$$ Then the intersection of all of these subsets a single point.

Proofs: 1

Proofs: 1


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References

Bibliography

  1. Forster Otto: "Analysis 2, Differentialrechnung im \(\mathbb R^n\), Gewöhnliche Differentialgleichungen", Vieweg Studium, 1984