diff --git a/Bookshelf/Enderton/Logic.tex b/Bookshelf/Enderton/Logic.tex
index 1cf57f6..3ebb186 100644
--- a/Bookshelf/Enderton/Logic.tex
+++ b/Bookshelf/Enderton/Logic.tex
@@ -104,8 +104,8 @@ If $S$ is a set of wffs containing all the sentence symbols and closed under all
 \section{Exercises 1}%
 \hyperlabel{sec:exercises-1}
 
-\subsection{\sorry{Exercise 1.1}}%
-\hyperlabel{sub:exercise-1.1}
+\subsection{\sorry{Exercise 1.1.1}}%
+\hyperlabel{sub:exercise-1.1.1}
 
 Give three sentences in English together with translations into our formal
   language.
@@ -118,8 +118,8 @@ The sentences shoudl be chosen so as to have an interesting structure, and the
 
 \end{answer}
 
-\subsection{\sorry{Exercise 1.2}}%
-\hyperlabel{sub:exercise-1.2}
+\subsection{\sorry{Exercise 1.1.2}}%
+\hyperlabel{sub:exercise-1.1.2}
 
 Show that there are no wffs of length 2, 3, or 6, but that any other positive
   length is possible.
@@ -130,8 +130,8 @@ Show that there are no wffs of length 2, 3, or 6, but that any other positive
 
 \end{answer}
 
-\subsection{\sorry{Exercise 1.3}}%
-\hyperlabel{sub:exercise-1.3}
+\subsection{\sorry{Exercise 1.1.3}}%
+\hyperlabel{sub:exercise-1.1.3}
 
 Let $\alpha$ be a wff; let $c$ be the number of places at which binary
   connective symbols $(\land, \lor, \Rightarrow, \Leftrightarrow)$ occur in
@@ -146,8 +146,8 @@ Show by using the induction principle that $s = c + 1$.
 
 \end{answer}
 
-\subsection{\sorry{Exercise 1.4}}%
-\hyperlabel{sub:exercise-1.4}
+\subsection{\sorry{Exercise 1.1.4}}%
+\hyperlabel{sub:exercise-1.1.4}
 
 Assume we have a construction sequence ending in $\phi$, where $\phi$ does not
   contain the symbol $A_4$.
@@ -161,8 +161,8 @@ Show that the result is still a legal construction sequence.
 
 \end{answer}
 
-\subsection{\sorry{Exercise 1.5}}%
-\hyperlabel{sub:exercise-1.5}
+\subsection{\sorry{Exercise 1.1.5}}%
+\hyperlabel{sub:exercise-1.1.5}
 
 Suppose that $\alpha$ is a wff not containing the negation symbol $\neg$.
 \begin{enumerate}[(a)]
@@ -179,8 +179,8 @@ Suppose that $\alpha$ is a wff not containing the negation symbol $\neg$.
 
 \end{answer}
 
-\subsection{\sorry{Exercise 1.6}}%
-\hyperlabel{sub:exercise-1.6}
+\subsection{\sorry{Exercise 1.1.6}}%
+\hyperlabel{sub:exercise-1.1.6}
 
 Suppose that $\alpha$ is a wff not containing the negation symbol $\neg$.
 \begin{enumerate}[(a)]