diff --git a/Compiler/Hoopl/Dataflow.hs b/Compiler/Hoopl/Dataflow.hs
--- a/Compiler/Hoopl/Dataflow.hs
+++ b/Compiler/Hoopl/Dataflow.hs
@@ -57,7 +57,7 @@
 
 module Compiler.Hoopl.Dataflow 
   ( DataflowLattice(..)
-  , ChangeFlag(..)
+  , ChangeFlag(..), changeIf
   , ForwardPass(..),  FwdTransfer, FwdRewrite, SimpleFwdRewrite
   , noFwdRewrite, thenFwdRw, shallowFwdRw, deepFwdRw
   , BackwardPass(..), BwdTransfer, BwdRewrite, SimpleBwdRewrite
@@ -82,10 +82,13 @@
   fact_name       :: String,                   -- Documentation
   fact_bot        :: a,                        -- Lattice bottom element
   fact_extend     :: a -> a -> (ChangeFlag,a), -- Lattice join plus change flag
+                                               -- (changes iff result > first arg)
   fact_do_logging :: Bool                      -- log changes
 }
 
 data ChangeFlag = NoChange | SomeChange
+changeIf :: Bool -> ChangeFlag
+changeIf changed = if changed then SomeChange else NoChange
 
 -----------------------------------------------------------------------------
 --		Analyze and rewrite forward: the interface
diff --git a/Compiler/Hoopl/GraphUtil.hs b/Compiler/Hoopl/GraphUtil.hs
new file mode 100644
--- /dev/null
+++ b/Compiler/Hoopl/GraphUtil.hs
@@ -0,0 +1,63 @@
+{-# LANGUAGE GADTs #-}
+{-# OPTIONS_GHC -fno-warn-incomplete-patterns #-} -- bug in GHC
+
+-- N.B. addBasicBlocks won't work on OO without a Node (branch/label) constraint
+
+module Compiler.Hoopl.GraphUtil
+  ( gCat, addEntrySeq, addExitSeq -- , addBasicBlocks
+  , gCatClosed
+  , gCatAny
+  , bodyGraph
+  )
+
+where
+
+import Compiler.Hoopl.Graph
+
+bodyGraph :: Body n -> Graph n C C
+bodyGraph b = GMany NothingO b NothingO
+
+
+gCatAny        :: Graph n e a -> Graph n a x -> Graph n e x
+gCat           :: Graph n e O -> Graph n O x -> Graph n e x
+addEntrySeq    :: Graph n O C -> Graph n C x -> Graph n O x
+addExitSeq     :: Graph n e C -> Graph n C O -> Graph n e O
+--addBasicBlocks :: Graph n e x -> Graph n C C -> Graph n e x
+gCatClosed     :: Graph n e C -> Graph n C x -> Graph n e x
+
+gCatAny GNil g2 = g2
+gCatAny g1 GNil = g1
+
+gCatAny (GUnit b1) (GUnit b2)             
+  = GUnit (b1 `BCat` b2)
+
+gCatAny (GUnit b) (GMany (JustO e) bs x) 
+  = GMany (JustO (b `BCat` e)) bs x
+
+gCatAny (GMany e bs (JustO x)) (GUnit b2) 
+  = GMany e bs (JustO (x `BCat` b2))
+
+gCatAny (GMany e1 bs1 (JustO x1)) (GMany (JustO e2) bs2 x2)
+  = GMany e1 (addBlock (x1 `BCat` e2) bs1 `BodyCat` bs2) x2
+
+gCatAny (GMany e1 bs1 NothingO) (GMany NothingO bs2 x2)
+   = GMany e1 (bs1 `BodyCat` bs2) x2
+
+gCat = gCatAny
+addEntrySeq = gCatAny
+addExitSeq = gCatAny
+gCatClosed = gCatAny
+
+{-
+addEntrySeq (GMany entry body NothingO) (GMany NothingO body' exit) 
+  = GMany entry (body `BodyCat` body') exit
+  
+addExitSeq  (GMany entry body NothingO) (GMany NothingO body' exit) 
+  = GMany entry (body `BodyCat` body') exit
+  
+--addBasicBlocks GNil g2 = g2
+
+
+gCatClosed (GMany e1 bs1 NothingO) (GMany NothingO bs2 x2)
+   = GMany e1 (bs1 `BodyCat` bs2) x2
+-}
diff --git a/Compiler/Hoopl/Label.hs b/Compiler/Hoopl/Label.hs
--- a/Compiler/Hoopl/Label.hs
+++ b/Compiler/Hoopl/Label.hs
@@ -5,8 +5,9 @@
   , FactBase, noFacts, mkFactBase, unitFact, lookupFact, extendFactBase
             , delFromFactBase, unionFactBase
             , elemFactBase, factBaseLabels, factBaseList
-  , LabelSet, emptyLabelSet, extendLabelSet, mkLabelSet, elemLabelSet, labelSetElems
-            , minusLabelSet, unionLabelSet
+  , LabelSet, emptyLabelSet, extendLabelSet, reduceLabelSet
+            , mkLabelSet, elemLabelSet, labelSetElems
+            , minusLabelSet, unionLabelSet, interLabelSet, sizeLabelSet, 
   )
 
 where
@@ -73,7 +74,7 @@
 delFromFactBase fb blks = foldr (M.delete . unLabel . fst) fb blks
 
 ----------------------
-type LabelSet = S.IntSet
+type LabelSet = S.IntSet -- ought to be a newtype or we expose the rep...
 
 emptyLabelSet :: LabelSet
 emptyLabelSet = S.empty
@@ -81,6 +82,9 @@
 extendLabelSet :: LabelSet -> Label -> LabelSet
 extendLabelSet lbls (Label bid) = S.insert bid lbls
 
+reduceLabelSet :: LabelSet -> Label -> LabelSet
+reduceLabelSet lbls (Label bid) = S.delete bid lbls
+
 elemLabelSet :: Label -> LabelSet -> Bool
 elemLabelSet (Label bid) lbls = S.member bid lbls
 
@@ -93,6 +97,13 @@
 unionLabelSet :: LabelSet -> LabelSet -> LabelSet
 unionLabelSet = S.union
 
+interLabelSet :: LabelSet -> LabelSet -> LabelSet
+interLabelSet = S.intersection
+
+sizeLabelSet :: LabelSet -> Int
+sizeLabelSet = S.size
+
 mkLabelSet :: [Label] -> LabelSet
 mkLabelSet = S.fromList . map unLabel
+
 
diff --git a/Compiler/Hoopl/MkGraph.hs b/Compiler/Hoopl/MkGraph.hs
--- a/Compiler/Hoopl/MkGraph.hs
+++ b/Compiler/Hoopl/MkGraph.hs
@@ -2,9 +2,10 @@
 module Compiler.Hoopl.MkGraph
     ( AGraph, (<*>)
     , emptyAGraph, withFreshLabels
-    , mkMiddle, mkMiddles, mkLast, mkEntry, mkBranch, mkLabel, mkWhileDo
+    , mkFirst, mkMiddle, mkMiddles, mkLast, mkEntry, mkBranch, mkLabel, mkWhileDo
     , addEntrySeq, addExitSeq, catAGraphs
     , IfThenElseable(mkIfThenElse)
+    , Node(mkLabelNode, mkBranchNode)
     )
 where
 
diff --git a/README b/README
new file mode 100644
--- /dev/null
+++ b/README
@@ -0,0 +1,17 @@
+This is Hoopl, a higher-order optimization library.
+There are two unpublished papers describing Hoopl:
+
+  Hoopl: Dataflow Optimization Made Simple
+  Hoopl: A Modular, Reusable Library for Dataflow Analysis and Transformation
+
+The second such paper is attached to this package.
+
+The version number is split into four parts:
+
+  3.   Third major body plan (phylum)
+  7.   Seventh iteration (roughly) of data structures
+  2.   Major version; changes when clients must change
+  1.   Minor version; changes when clients can stay the same
+
+
+Version 3.7.2.2 has KNOWN BUGS!  John Dias will update soon.
diff --git a/hoopl.cabal b/hoopl.cabal
--- a/hoopl.cabal
+++ b/hoopl.cabal
@@ -1,5 +1,5 @@
 Name:                hoopl
-Version:             3.7.1.0
+Version:             3.7.2.2
 Description:         Higher-order optimization library
 License:             BSD3
 License-file:        LICENSE
@@ -9,6 +9,7 @@
 Cabal-Version:       >=1.2
 Synopsis:            A library to support dataflow analysis and optimization
 Category:            Compilers/Interpeters
+Extra-source-files:  README, hoopl.pdf
 
 Library
   Build-Depends:     base >= 3 && < 5, containers
@@ -16,4 +17,5 @@
                      Compiler.Hoopl.Dataflow, Compiler.Hoopl.Graph, 
                      Compiler.Hoopl.MkGraph,
                      Compiler.Hoopl.Fuel, Compiler.Hoopl.Label
+  Other-modules:     Compiler.Hoopl.GraphUtil
   ghc-options:       -Wall -fno-warn-name-shadowing
diff --git a/hoopl.pdf b/hoopl.pdf
new file mode 100644
Binary files /dev/null and b/hoopl.pdf differ