s/practical, interpretation/practical interpretation/ (hmemcpy#273)

src/content/1.9/function-types.tex

@@ -462,7 +462,7 @@ \subsection{Exponentials of Sums}
 \[a^{b+c} = a^{b} \times a^{c}\]
 Categorically, this says that the exponential from a coproduct of two
 objects is isomorphic to a product of two exponentials. In Haskell, this
-algebraic identity has a very practical, interpretation. It tells us
+algebraic identity has a very practical interpretation. It tells us
 that a function from a sum of two types is equivalent to a pair of
 functions from individual types. This is just the case analysis that we
 use when defining functions on sums. Instead of writing one function