Exercises
[15W] Let \(Iββ\) be an interval, and let \(f:Iββ\) be uniformly continuous. Let \(π\) be the continuity modulus, defined by the eqz.Β [(13.16)], as in the exercise [156]. Show that \(π\) is subadditive i.e.
\[ π(t)+π(s)β₯ π(t+s)\quad . \]Knowing that \(\lim _{tβ 0+}π(t)=0\) we conclude that \(π\) is continuous.
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