Update rings.tex (#232)

Small edit on requirements for a Euclidean Norm

tex/H113/rings.tex

@@ -431,7 +431,7 @@ \section{Extra: Euclidean domains}
 It's the absolute value $|\cdot|$ which is used to compare the magnitude of two numbers,
 and this absolute value satisfies two conditions:
 \begin{itemize}
-	\ii It takes nonnegative integer values --- that way, the algorithm will eventually terminate.
+	\ii It outputs nonnegative integer values --- that way, the algorithm will eventually terminate.
 	\ii For any two ring elements $a$ and $b$, where $b \neq 0$, there exist some $q$ such that
 	$r = a-qb$ has smaller absolute value than $b$.
 \end{itemize}