EDB — 0NF

Exercises

1. [0NF] Let \((x_ n)_ n\) be a sequence such that \(∑_{n=1}^∞ d(x_ n,x_{n+1}) {\lt} ∞\): prove that it is a Cauchy sequence.

   Compare this exercise, the previous [0NC]↺↻ in case \(∑_ n \varepsilon _ n{\lt}∞\), and exercise [0N8]↺↻.