penultimate Springer draft

--- a/doc-src/Ref/undocumented.tex	Fri Apr 15 18:04:01 1994 +0200
+++ b/doc-src/Ref/undocumented.tex	Fri Apr 15 18:10:49 1994 +0200
@@ -244,8 +244,6 @@
 flex-flex pairs by choosing the obvious unifier. It may be used to tidy up
 any flex-flex pairs remaining at the end of a proof.
 
-\subsubsection{Flexible-flexible disagreement pairs}
-
 
 \subsubsection{Multiple unifiers}
 The unification procedure performs Huet's {\sc match} operation