Add documentation on the hasfree data object.
diff --git a/Doc/lib/libdis.tex b/Doc/lib/libdis.tex
index 2a285d2..174d487 100644
--- a/Doc/lib/libdis.tex
+++ b/Doc/lib/libdis.tex
@@ -85,6 +85,10 @@
 Sequence of byte codes that have a constant parameter.
 \end{datadesc}
 
+\begin{datadesc}{hasfree}
+Sequence of byte codes that access a free variable.
+\end{datadesc}
+
 \begin{datadesc}{hasname}
 Sequence of byte codes that access an attribute by name.
 \end{datadesc}