diff --git a/background.tex b/background.tex
index 9550b00cebc11e114d034d141af6eda4f17f0544..93b720caeb2d61f0872c79f93b2917af4f7c3c6a 100644
--- a/background.tex
+++ b/background.tex
@@ -89,9 +89,11 @@
 \end{example}
 
 \begin{example}\label{ex:cat}
-  The \de{category} of functors \(\fc{\C}{\D}\)
-  has \defn{category}{categories} as \des{object} and \des{functor} as
-  \des{morphism}, given that \(\C\) is \de{small}.
+  Given the \defn{category}{categories} \(\C\) (\de{small}) and
+  \(\D\), the \emph{functor category} \(\fc{\C}{\D}\) has
+  \des{functor} \(F : \map{\C}{\D}\) as \des{object} and
+  \defn{nattran}{natural transformations} \(\eta : \map{F}{G}\) as
+  \des{morphism}.
 \end{example}
 
 \begin{example}\label{ex:veck}