Ex 1.1: typo aab -> abv

info/exercises/src/ex-01/ex/languages.tex

@@ -134,7 +134,7 @@
       such that \(w_1 = a\), \(w_2 = a\), and \(w_{i + 2} = v_i\) for \(1 \le i
       \le m\). Since \(m < |v|\) and \(|v| = |w| - 2\), \(m + 2 < |w|\). QED.
 
-      \item \(w = aab\): by the same argument as the previous case, \(v\) has a decomposition
+      \item \(w = abv\): by the same argument as the previous case, \(v\) has a decomposition
       into words in \(\{a, ab\}\), \(v = v_1\ldots v_m\) for some \(m < |v|\)
       and \(v_i \in \{a, ab\}\).