Solution
= Solution
A <sequence> $(a_n)$ is Cauchy when, for every $\varepsilon>0$, some $N$ satisfies $|a_m-a_n|<\varepsilon$ whenever $m,n\ge N$.
= Solution
A <sequence> $(a_n)$ is Cauchy when, for every $\varepsilon>0$, some $N$ satisfies $|a_m-a_n|<\varepsilon$ whenever $m,n\ge N$.