In the first one, they already defined upper bound and least upper bound beforehand, so the statement is more concise than the Strichartz's one. On the other hand, the proof of the completeness axiom, or rather a…
In the first one, they already defined upper bound and least upper bound beforehand, so the statement is more concise than the Strichartz's one. On the other hand, the proof of the completeness axiom, or rather a…