diff --git a/transformations/ImplicitMobility.hs b/transformations/ImplicitMobility.hs
index 4fb1c7f..6c83f37 100644
--- a/transformations/ImplicitMobility.hs
+++ b/transformations/ImplicitMobility.hs
@@ -183,7 +183,7 @@ effectMoveCopyDecisions g decs = foldFuncsM $ map effect $ Map.toList decs
           Nothing -> const $ dieP (findMeta v) "Could not find label for node"
           Just mod -> effectDecision v dec mod
 
-implicitMobility :: Pass
+implicitMobility :: Pass A.AST
 implicitMobility 
   = pass "Implicit mobility optimisation"
     [] [] --TODO properties
diff --git a/transformations/SimplifyAbbrevs.hs b/transformations/SimplifyAbbrevs.hs
index db2833f..3521b15 100644
--- a/transformations/SimplifyAbbrevs.hs
+++ b/transformations/SimplifyAbbrevs.hs
@@ -41,7 +41,7 @@ import Traversal
 import UsageCheckUtils
 import Utils
 
-simplifyAbbrevs :: [Pass]
+simplifyAbbrevs :: [Pass A.AST]
 simplifyAbbrevs =
     [ removeInitial
     , removeResult
@@ -49,14 +49,14 @@ simplifyAbbrevs =
     ]
 
 -- | Rewrite 'InitialAbbrev' into a variable and an assignment.
-removeInitial :: Pass
+removeInitial :: PassOnOps (ExtOpMSP BaseOp)
 removeInitial
     = pass "Remove INITIAL abbreviations"
            []
            [Prop.initialRemoved]
-           (applyDepthSM doStructured)
+           (applyBottomUpMS doStructured)
   where
-    doStructured :: Data t => A.Structured t -> PassM (A.Structured t)
+    doStructured :: TransformStructured (ExtOpMSP BaseOp)
     doStructured (A.Spec m spec s) = doSpec m spec s
     doStructured s = return s
 
@@ -166,25 +166,24 @@ removeInitial
         specVar (A.Specification m n _) = A.Variable m n
 
 -- | Rewrite 'ResultAbbrev' into just 'Abbrev'.
-removeResult :: Pass
+removeResult :: Polyplate t (OneOp A.AbbrevMode) () => Pass t
 removeResult
     = pass "Remove RESULT abbreviations"
            []
            [Prop.resultRemoved]
-           (applyDepthM (return . doAbbrevMode))
+           (return . applyBottomUp doAbbrevMode)
   where
     doAbbrevMode :: A.AbbrevMode -> A.AbbrevMode
     doAbbrevMode A.ResultAbbrev = A.Abbrev
     doAbbrevMode s = s
 
 -- | Rewrite abbreviation modes in the state.
-updateAbbrevsInState :: Pass
+updateAbbrevsInState :: Pass t
 updateAbbrevsInState
     = pass "Update INITIAL and RESULT abbreviations in state"
            [Prop.initialRemoved, Prop.resultRemoved]
            []
-           (\v -> get >>* doNameAbbrevs >>= applyDepthM (return . doAbbrevMode)
-                    >>= put >> return v)
+           (\v -> get >>= applyDepthM (return . doAbbrevMode) >>= put >> return v)
   where
     doAbbrevMode :: A.AbbrevMode -> A.AbbrevMode
     doAbbrevMode A.InitialAbbrev = A.Original
diff --git a/transformations/SimplifyTypes.hs b/transformations/SimplifyTypes.hs
index 1ff5af7..7e8a983 100644
--- a/transformations/SimplifyTypes.hs
+++ b/transformations/SimplifyTypes.hs
@@ -34,13 +34,13 @@ import Traversal
 import Types
 import Utils
 
-simplifyTypes :: [Pass]
+simplifyTypes :: [Pass A.AST]
 simplifyTypes
   = [ resolveNamedTypes
     ]
 
 -- | Turn named data types into their underlying types.
-resolveNamedTypes :: Pass
+resolveNamedTypes :: PassOn A.Type
 resolveNamedTypes
     = pass "Resolve user-defined types"
            (Prop.agg_namesDone
@@ -49,21 +49,9 @@ resolveNamedTypes
            (\t -> do get >>= resolve >>= flatten >>= onCsNames (flatten <.< resolve) >>= put
                      resolve t >>= flatten)
   where
-    -- Work-around for data types not being resolved:
-    onCsNames :: Transform A.NameDef -> Transform CompState
-    onCsNames f cs = do csNames' <- T.mapM f $ csNames cs
-                        return $ cs { csNames = csNames' }
-    
     resolve :: PassType
     resolve = applyDepthM doType
       where
         doType :: A.Type -> PassM A.Type
         doType t@(A.UserDataType _) = underlyingType emptyMeta t
         doType t = return t
-
-    flatten :: PassType
-    flatten = applyDepthM doType
-      where
-        doType :: Transform A.Type
-        doType (A.Array dsA (A.Array dsB t)) = return $ A.Array (dsA++dsB) t
-        doType t = return t