Typo, spotted by Detlef Lannert.

Doc/lib/libweakref.tex

@@ -53,7 +53,7 @@ be made to support weak references; see section \ref{weakref-extension},
   
   Weak references support tests for equality, but not ordering.  If
   the referents are still alive, two references have the same
-  equalality relationship as their referents (regardless of the
+  equality relationship as their referents (regardless of the
   \var{callback}).  If either referent has been deleted, the
   references are equal only if the reference objects are the same
   object.