6.3 Supremum and infimum[29M]
Let’s first review the characterizations of the supremum and infimum in \(ℝ\), as seen in Sec. [1YY] (or in Chap. 1 Sect. 5 in the notes [ 3 ] ). Let \(A⊆ ℝ\) be a non empty set.
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Exercises
Let \(I,J\) be generic non-empty sets. See definitions in Sec. 6.3