Add zlib
diff --git a/Doc/lib/lib.tex b/Doc/lib/lib.tex
index f9e23aa..4839415 100644
--- a/Doc/lib/lib.tex
+++ b/Doc/lib/lib.tex
@@ -121,6 +121,7 @@
\input{libthread}
\input{libanydbm}
\input{libwhichdb}
+\input{libzlib}
\input{libunix} % UNIX Specific Services
\input{libposix}
diff --git a/Doc/lib/libsomeos.tex b/Doc/lib/libsomeos.tex
index 49c1ab2..c04cf7a 100644
--- a/Doc/lib/libsomeos.tex
+++ b/Doc/lib/libsomeos.tex
@@ -22,7 +22,14 @@
\item[anydbm]
--- Generic interface to DBM-style database modules.
+
\item[whichdbm]
--- Guess which DBM-style module created a given database.
+\item[zlib]
+\item[gzip]
+--- Compression and decompression compatible with the
+\code{gzip} program (zlib is the low-level interface, gzip the
+high-level one).
+
\end{description}