@@ -87,3 +87,7 @@ ENV/
 
 # Rope project settings
 .ropeproject
+
+
+Untitled*
+*~
@@ -17,7 +17,7 @@ PDFFLAGS = -dCompatibilityLevel=1.4 -dPDFSETTINGS=/prepress \
 	ps2pdf $(PDFFLAGS) $<
 
 all:	book.tex
-	pdflatex --shell-escape book
+	pdflatex $(PDFFLAGS) --shell-escape book
 	makeindex book.idx
 	evince book.pdf
 
 
@@ -13,7 +13,7 @@
 \newcommand{\thetitle}{Modeling and Simulation in Python}
 \newcommand{\thesubtitle}{}
 \newcommand{\theauthors}{Allen B. Downey}
-\newcommand{\theversion}{1.0.2}
+\newcommand{\theversion}{1.1}
 
 
 %%%% Both LATEX and PLASTEX
@@ -488,13 +488,15 @@ \section{Running Jupyter}
 about it at \url{http://jupyter.org}.
 \index{Jupyter}
 
+% TODO: Add Jupyter instructions
+
 [Jupyter instructions coming soon.]
 
 
 \section*{Contributor List}
 
 If you have a suggestion or correction, send it to 
-{\tt downey@allendowney.com}.  Or if you are a Git use, send me a pull request!
+{\tt downey@allendowney.com}.  Or if you are a Git user, send me a pull request!
 
 If I make a change based on your feedback, I will add you to the contributor list, unless you ask to be omitted.
 \index{contributors}
@@ -5600,6 +5602,8 @@ \section{Modeling baseball flight}
 
 Where $|v|$ indicates the magnitude of $v$ and the arrows on $\vec{F}_d$ and $\vec{v}$ indicate that they are vectors.  Negation reverses the direction of a vector, so $\vec{F}_d$ is in the opposite direction of $\vec{v}$.
 
+% TODO: introduce the hat function
+
 Translating to Python we have:
 
 \begin{python}