Can the Superior Limit of a Sequence Be Lower Than Its Supremum?

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SUMMARY

The discussion centers on the relationship between the superior limit (limsup) and the supremum of a sequence, specifically addressing whether the superior limit can be lower than the supremum. It is established that limsup can indeed be lower than the supremum, as illustrated by the example sequence \( x_n = 1 + \frac{1}{n} \), where the supremum is 2 and the limsup is 1. The key takeaway is that the supremum of a sequence does not necessarily dictate the value of its superior limit.

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Suppose there is some sequence [itex]\{x_n\}_{n\in\mathbb{N}}[/itex]. Say we have a set of all the limits of all possible subsequences, would the supremum of this set be the superior limit of [itex]\{x_n\}_{n\in\mathbb{N}}[/itex]? What about if this value turns out to be 5, but there is a member of the sequence that is equal to 500, but is not the limit of any subsequence. Can the superior limit be lower than the supremum of the sequence? Thanks!
 
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limsup may be lower than sup. Example xn = 1 + 1/n, sup = 2, limsup = 1.
 
Thanks, that was quite helpful.
 

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