Final answer:
To prove assertion (1), we use the Archimedean property and define a set K to find an integer m between an and bn.
Step-by-step explanation:
The provided question is related to proving the limit assertions in Exercise 20.2. To prove assertion (1), we need to show that there exists an integer m between an and bn. To do this, we use the Archimedean property to first find an integer k such that -k > b - a. We then define the set K as {j ∈ Z: -k ≤ j ≤ k}. Since an ≤ a ≤ b ≤ bn, there exists an integer m in K such that an ≤ m ≤ bn.