deletions | additions       diff --git a/lectures.tex b/lectures.tex  index f710bdc..8f2a3a1 100644  --- a/lectures.tex  +++ b/lectures.tex 
...
it features tight integration of text and graphics, which reduces skipping back and forth; and  it implements margin notes, which we use for quick reminders of mathematical formulae and side remarks. For an example, see Fig.~\ref{f.sample-handout-page}. Sketches for the handout, as shown in Fig.~\ref{f.sample-handout-page}, are made using the \href{https://evernote.com/penultimate/}{Penultimate} app on an iPad.  Fig.~\ref{f.sample-handout-page} also demonstrates how exercises Exercises  are built incorporated  into the text. body of the notes (Fig.~\ref{f.sample-handout-page}).  Typically a few exercises are assigned prior to the start of lecture as guides to reading the notes. Longer, more involved problems are then assigned as homework following the lecture. Solutions, which are written in the same format as the lecture notes, are distributed when the marked assignments are returned, and the solutions are discussed in lecture.