diff --git a/src/Dodge/Item/Grammar.hs b/src/Dodge/Item/Grammar.hs
index 603453019..0161d261d 100644
--- a/src/Dodge/Item/Grammar.hs
+++ b/src/Dodge/Item/Grammar.hs
@@ -33,8 +33,7 @@ import Dodge.DoubleTree
 import LensHelp
 import ListHelp
 
-tryAttachItems :: LDTree ItemLink CItem -> LDTree ItemLink CItem -> 
-    Maybe (LDTree ItemLink CItem)
+tryAttachItems :: DTree CItem -> DTree CItem -> Maybe (DTree CItem)
 tryAttachItems = leftRightCombine leftIsParentCombine rightIsParentCombine
 
 --breakListAbove :: Item -> ItemStructuralFunction -> [(ItemStructuralFunction, ItemLink)]
@@ -53,20 +52,20 @@ tryAttachItems = leftRightCombine leftIsParentCombine rightIsParentCombine
 --        [(JoystickSF, JoystickLink)]
 --    _ -> []
 
+--itemToBreakLists ::
+--    Item ->
+--    ItemStructuralFunction ->
+--    ([(ItemStructuralFunction, ItemLink)], [(ItemStructuralFunction, ItemLink)])
+--itemToBreakLists itm itmf = (fmap f l, fmap f r)
+--  where
+--    f x = (x, SFLink x)
+--    (l,r) = itemToBreakLists' itm itmf
+
 itemToBreakLists ::
-    Item ->
-    ItemStructuralFunction ->
-    ([(ItemStructuralFunction, ItemLink)], [(ItemStructuralFunction, ItemLink)])
-itemToBreakLists itm itmf = (fmap f l, fmap f r)
-  where
-    f x = (x, SFLink x)
-    (l,r) = itemToBreakLists' itm itmf
-
-itemToBreakLists' ::
     Item ->
     ItemStructuralFunction ->
     ([(ItemStructuralFunction)], [(ItemStructuralFunction)])
-itemToBreakLists' itm itmf = case (itm ^. itType, itmf) of
+itemToBreakLists itm itmf = case (itm ^. itType, itmf) of
     (HELD TORCH, _) -> (getAmmoLinks itm, [])
     (ATTACH UNDERBARRELSLOT, _) -> ([(UnderBarrelPlatformSF)], [])
     (_, HeldPlatformSF) ->
@@ -179,8 +178,8 @@ itemToFunction itm = case itm ^. itType of
     CLICKER{} -> GadgetPlatformSF
     _ -> NoSF
 
-treeToPotentialFunction :: LDTree ItemLink CItem -> S.Set ItemStructuralFunction
-treeToPotentialFunction ldt = case ldt ^. ldtValue . _1 . itType of
+treeToPotentialFunction :: DTree CItem -> S.Set ItemStructuralFunction
+treeToPotentialFunction ldt = case ldt ^. dtValue . _1 . itType of
     STICKYMOD -> S.singleton GrenadeHitEffectSF
     ATTACH GIMBAL -> S.singleton ProjectileStabiliserSF
     ATTACH GYROSCOPE -> S.singleton ProjectileStabiliserSF
@@ -188,52 +187,52 @@ treeToPotentialFunction ldt = case ldt ^. ldtValue . _1 . itType of
     HELD BURSTRIFLE -> S.singleton UnderBarrelPlatformSF
     HELD LASER -> S.fromList [WeaponTargetingSF,LaserWeaponSF]
     -- following limits items to ten ammo slots
-    _ | AmmoMagSF _ x <- ldt ^. ldtValue . _2 -> S.fromList [AmmoMagSF i x | i <- [0..9]]
-    _ -> S.singleton (ldt ^. ldtValue . _2)
+    _ | AmmoMagSF _ x <- ldt ^. dtValue . _2 -> S.fromList [AmmoMagSF i x | i <- [0..9]]
+    _ -> S.singleton (ldt ^. dtValue . _2)
 
 baseCI :: Item -> CItem
 baseCI itm = (itm, itemToFunction itm)
 
-type LDTComb a b = LDTree b a -> LDTree b a -> Maybe (LDTree b a)
+type DTComb a = DTree a -> DTree a -> Maybe (DTree a)
 
-leftIsParentCombine :: LDTComb CItem ItemLink
+leftIsParentCombine :: DTComb CItem
 leftIsParentCombine ltree rtree = do
     let l = rightChildList ltree
-        xs = dropWhile ((\s -> not $ S.member s (treeToPotentialFunction rtree)) . fst) l
-    (sf,linktype) <- safeHead xs
-    return $ ltree & ldtRight .:~ (linktype, rtree & ldtValue . _2 .~ sf)
+        xs = dropWhile ((\s -> not $ S.member s (treeToPotentialFunction rtree))) l
+    (sf) <- safeHead xs
+    return $ ltree & dtRight .:~ ( rtree & dtValue . _2 .~ sf)
 
-rightIsParentCombine :: LDTComb CItem ItemLink
+rightIsParentCombine :: DTComb CItem
 rightIsParentCombine ltree rtree = do
     let l = leftChildList rtree
-        xs = dropWhile ((\s -> not $ S.member s (treeToPotentialFunction ltree)) . fst) l
-    (sf,linktype) <- safeHead xs
-    return $ rtree & ldtLeft .:~ (linktype, ltree & ldtValue . _2 .~ sf)
+        xs = dropWhile ((\s -> not $ S.member s (treeToPotentialFunction ltree))) l
+    (sf) <- safeHead xs
+    return $ rtree & dtLeft .:~ ( ltree & dtValue . _2 .~ sf)
 
-leftChildList :: LDTree ItemLink CItem -> [(ItemStructuralFunction, ItemLink)]
-leftChildList t = foldl' f l (reverse $ t ^.. ldtLeft . each . _2 . ldtValue . _2)
+leftChildList :: DTree CItem -> [ItemStructuralFunction]
+leftChildList t = foldl' f l (reverse $ t ^.. dtLeft . each . dtValue . _2)
   where
-    l = fst $ itemToBreakLists (t ^. ldtValue . _1) (t ^. ldtValue . _2)
-    f x y = tail $ dropWhile ((/=y) . fst) x
+    l = fst $ itemToBreakLists (t ^. dtValue . _1) (t ^. dtValue . _2)
+    f x y = tail $ dropWhile ((/=y) ) x
 
-rightChildList :: LDTree ItemLink CItem -> [(ItemStructuralFunction, ItemLink)]
-rightChildList t = foldl' f l (reverse $ t ^.. ldtRight . each . _2 . ldtValue . _2)
+rightChildList :: DTree CItem -> [ItemStructuralFunction]
+rightChildList t = foldl' f l (reverse $ t ^.. dtRight . each . dtValue . _2)
   where
-    l = snd $ itemToBreakLists (t ^. ldtValue . _1) (t ^. ldtValue . _2)
-    f x y = tail $ dropWhile ((/=y) . fst) x
+    l = snd $ itemToBreakLists (t ^. dtValue . _1) (t ^. dtValue . _2)
+    f x y = tail $ dropWhile ((/=y)) x
 
 leftRightCombine ::
-    LDTComb a b ->
-    LDTComb a b ->
-    LDTree b a ->
-    LDTree b a ->
-    Maybe (LDTree b a)
+    DTComb a ->
+    DTComb a ->
+    DTree a ->
+    DTree a ->
+    Maybe (DTree a)
 leftRightCombine f f' t1 t2 = f t1 t2 <|> checkdepth t1 t2
   where
-    checkdepth t t'@(LDT x ls rs) = fromMaybe (checktop t t') $ do
-        (lab, t'') <- safeHead ls
+    checkdepth t t'@(DT x ls rs) = fromMaybe (checktop t t') $ do
+        (t'') <- safeHead ls
         tx <- checkdepth t t''
-        return $ Just $ LDT x ((lab, tx) : tail ls) rs
+        return $ Just $ DT x (( tx) : tail ls) rs
     checktop t t' = f' t t'
 
 joinItemsInList :: (a -> a -> Maybe a) -> [a] -> [a]
@@ -252,9 +251,9 @@ joinItemsInList f = fst . h . ([],)
 --        . fmap (singleLDT . baseCI)
 
 invDT :: IM.IntMap Item -> [DTree CItem]
-invDT = fmap ldtToDT .
+invDT = 
     joinItemsInList tryAttachItems . IM.elems
-        . fmap (singleLDT . baseCI)
+        . fmap (singleDT . baseCI)
 
 --invLDT' :: IM.IntMap Item -> [LDTree ItemLink OItem]
 --invLDT' = fmap propagateOrientation . invLDT
diff --git a/tags b/tags
index c7919dd9a..dd2a945ce 100644
--- a/tags
+++ b/tags
@@ -434,6 +434,7 @@ DRUMMAG	src/Dodge/Data/Item/Combine.hs	107;"	C
 DS	src/DoubleStack.hs	3;"	t
 DT	src/Dodge/Data/DoubleTree.hs	31;"	C
 DTBottomNode	src/Dodge/Data/DoubleTree.hs	21;"	C
+DTComb	src/Dodge/Item/Grammar.hs	196;"	t
 DTMidAboveNode	src/Dodge/Data/DoubleTree.hs	19;"	C
 DTMidBelowNode	src/Dodge/Data/DoubleTree.hs	20;"	C
 DTRootNode	src/Dodge/Data/DoubleTree.hs	17;"	C
@@ -969,7 +970,6 @@ Kill	src/Dodge/Data/ActionPlan.hs	198;"	C
 LASER	src/Dodge/Data/Item/Combine.hs	168;"	C
 LDT	src/Dodge/Data/DoubleTree.hs	34;"	C
 LDTBottomNode	src/Dodge/Data/DoubleTree.hs	29;"	C
-LDTComb	src/Dodge/Item/Grammar.hs	196;"	t
 LDTMidAboveNode	src/Dodge/Data/DoubleTree.hs	27;"	C
 LDTMidBelowNode	src/Dodge/Data/DoubleTree.hs	28;"	C
 LDTRootNode	src/Dodge/Data/DoubleTree.hs	25;"	C
@@ -3348,7 +3348,6 @@ airlockDoor	src/Dodge/Room/Airlock.hs	51;"	f
 airlockDoubleDoor	src/Dodge/Room/Airlock.hs	54;"	f
 airlockSimple	src/Dodge/Room/Airlock.hs	66;"	f
 airlockZ	src/Dodge/Room/Airlock.hs	91;"	f
-allInvLocs	src/Dodge/Item/Grammar.hs	329;"	f
 allVisibleWalls	src/Dodge/Base/Collide.hs	132;"	f
 alongSegBy	src/Geometry.hs	40;"	f
 alteRifle	src/Dodge/Item/Held/Cane.hs	22;"	f
@@ -3561,6 +3560,7 @@ cardList	src/Dodge/Base/CardinalPoint.hs	6;"	f
 cardVec	src/Dodge/Base/CardinalPoint.hs	9;"	f
 cardinalVectors	src/Dodge/FloorItem.hs	43;"	f
 cartePosToScreen	src/Dodge/Base/Coordinate.hs	37;"	f
+cdtPropagateFold	src/Dodge/DoubleTree.hs	407;"	f
 cenLasTur	src/Dodge/Room/LasTurret.hs	24;"	f
 centerText	src/Picture/Base.hs	184;"	f
 centerVaultExplosiveExit	src/Dodge/Room/NoNeedWeapon.hs	20;"	f
@@ -3621,7 +3621,7 @@ clampPath	src/Dodge/Room/Procedural.hs	166;"	f
 clang1S	src/Dodge/SoundLogic/ExternallyGeneratedSounds.hs	549;"	f
 clang2S	src/Dodge/SoundLogic/ExternallyGeneratedSounds.hs	663;"	f
 clangS	src/Dodge/SoundLogic/ExternallyGeneratedSounds.hs	531;"	f
-cldtPropagateFold	src/Dodge/DoubleTree.hs	352;"	f
+cldtPropagateFold	src/Dodge/DoubleTree.hs	358;"	f
 cleanUpPreload	src/Preload.hs	10;"	f
 cleanUpRenderPreload	src/Preload/Render.hs	217;"	f
 cleanUpSoundPreload	src/Preload.hs	15;"	f
@@ -4656,10 +4656,8 @@ invHead	src/Dodge/Render/HUD.hs	405;"	f
 invIMDT	src/Dodge/Item/Grammar.hs	295;"	f
 invIndents	src/Dodge/Item/Grammar.hs	307;"	f
 invItemLocUpdate	src/Dodge/Creature/State.hs	153;"	f
-invLDT	src/Dodge/Item/Grammar.hs	248;"	f
 invRootItemEffs	src/Dodge/Creature/State.hs	146;"	f
 invRootMap	src/Dodge/Item/Grammar.hs	268;"	f
-invRootTrees	src/Dodge/Item/Grammar.hs	289;"	f
 invSelectionItem	src/Dodge/Inventory/SelectionList.hs	32;"	f
 invSetSelection	src/Dodge/Inventory.hs	185;"	f
 invSetSelectionPos	src/Dodge/Inventory.hs	193;"	f
@@ -4736,8 +4734,7 @@ itemScrollDisplay	src/Dodge/Inventory/SelectionList.hs	121;"	f
 itemScrollValue	src/Dodge/Inventory/SelectionList.hs	148;"	f
 itemSidePush	src/Dodge/HeldUse.hs	418;"	f
 itemString	src/Dodge/Item/Display.hs	56;"	f
-itemToBreakLists	src/Dodge/Item/Grammar.hs	55;"	f
-itemToBreakLists'	src/Dodge/Item/Grammar.hs	64;"	f
+itemToBreakLists	src/Dodge/Item/Grammar.hs	64;"	f
 itemToFunction	src/Dodge/Item/Grammar.hs	147;"	f
 itemTreeSPic	src/Dodge/Item/Draw/SPic.hs	24;"	f
 itemTriggerType	src/Dodge/BaseTriggerType.hs	15;"	f
@@ -4845,12 +4842,14 @@ loadSounds	src/Dodge/SoundLogic/LoadSound.hs	18;"	f
 loadingScreen	src/Dodge/Concurrent.hs	56;"	f
 loadingScreen	src/Dodge/Menu/Loading.hs	8;"	f
 loadme	src/Dodge/Debug/Terminal.hs	139;"	f
-locDTGoHelp	src/Dodge/DoubleTree.hs	342;"	f
-locDTGoLeft	src/Dodge/DoubleTree.hs	323;"	f
-locDTGoRight	src/Dodge/DoubleTree.hs	328;"	f
-locGoHelp	src/Dodge/DoubleTree.hs	334;"	f
-locGoLeft	src/Dodge/DoubleTree.hs	313;"	f
-locGoRight	src/Dodge/DoubleTree.hs	318;"	f
+locDTGoHelp	src/Dodge/DoubleTree.hs	348;"	f
+locDTGoLeft	src/Dodge/DoubleTree.hs	329;"	f
+locDTGoRight	src/Dodge/DoubleTree.hs	334;"	f
+locDTLeftmost	src/Dodge/DoubleTree.hs	312;"	f
+locDTRightmost	src/Dodge/DoubleTree.hs	315;"	f
+locGoHelp	src/Dodge/DoubleTree.hs	340;"	f
+locGoLeft	src/Dodge/DoubleTree.hs	319;"	f
+locGoRight	src/Dodge/DoubleTree.hs	324;"	f
 locLDTToLocDT	src/Dodge/DoubleTree.hs	19;"	f
 locLeftmost	src/Dodge/DoubleTree.hs	306;"	f
 locOrient	src/Dodge/Item/HeldOffset.hs	57;"	f
@@ -5484,8 +5483,8 @@ rectXH	src/Geometry/Polygon.hs	32;"	f
 rectXY	src/Geometry/Polygon.hs	35;"	f
 rectanglePairs	src/Dodge/LevelGen/DoorPane.hs	7;"	f
 red	src/Color.hs	14;"	f
-reduceLocDT	src/Dodge/DoubleTree.hs	392;"	f
-reduceLocLDT	src/Dodge/DoubleTree.hs	387;"	f
+reduceLocDT	src/Dodge/DoubleTree.hs	398;"	f
+reduceLocLDT	src/Dodge/DoubleTree.hs	393;"	f
 reflDirWall	src/Dodge/Base/Wall.hs	16;"	f
 reflVelWall	src/Dodge/Base/Wall.hs	24;"	f
 reflVelWallDamp	src/Dodge/Base/Wall.hs	20;"	f
@@ -6149,7 +6148,7 @@ triggerSwitchSPicLight	src/Dodge/Placement/Instance/Button.hs	31;"	f
 truncFaces	src/Polyhedra/Geodesic.hs	53;"	f
 truncate	src/Polyhedra/Geodesic.hs	38;"	f
 trunkDepth	src/TreeHelp.hs	161;"	f
-tryAttachItems	src/Dodge/Item/Grammar.hs	35;"	f
+tryAttachItems	src/Dodge/Item/Grammar.hs	36;"	f
 tryClickUse	src/Dodge/Creature/YourControl.hs	221;"	f
 tryCombine	src/Dodge/Update/Input/InGame.hs	526;"	f
 tryDropSelected	src/Dodge/Update/Input/InGame.hs	125;"	f