Enderton. Fix up note on theorem ordering.

Bookshelf/Enderton/Set.tex

@@ -6234,9 +6234,7 @@ Show that $<_L$ is a linear ordering on $A \times B$.
 \end{theorem}
 
 \begin{note}
-  Notice this theorem comes after \nameref{sub:theorem-4e}. Enderton introduces
+  This theorem depends on \nameref{sub:theorem-4e} and \nameref{sub:theorem-4f}.
-  this theorem before \nameref{sub:theorem-4e} but its proof relies on
-  \nameref{sub:theorem-4e}.
 \end{note}
 
 \begin{proof}