Definition 16.3.2 (Positive and Negative Parts). Let $X$ be a set and $f: X \to \real$ be a function, then
\[f^{+} = \max(f, 0) \quad f^{-} = -\min(f, 0)\]
are the positive and negative parts of $f$, and $f = f^{+} - f^{-}$.
Definition 16.3.2 (Positive and Negative Parts). Let $X$ be a set and $f: X \to \real$ be a function, then
are the positive and negative parts of $f$, and $f = f^{+} - f^{-}$.