Typo: "Availabilty" --> "Availability"
Thanks to /F!
diff --git a/Doc/lib/libos.tex b/Doc/lib/libos.tex
index a794fa7..c6f74f5 100644
--- a/Doc/lib/libos.tex
+++ b/Doc/lib/libos.tex
@@ -651,7 +651,7 @@
 \begin{funcdesc}{plock}{op}
 Lock program segments into memory.  The value of \var{op}
 (defined in \code{<sys/lock.h>}) determines which segments are locked.
-Availabilty: \UNIX{}.
+Availability: \UNIX{}.
 \end{funcdesc}
 
 \begin{funcdesc}{spawnv}{mode, path, args}