diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,35 @@
+
+0.18,0 to 0.19.0:
+  
+  * Added @Transform@ type class to apply a matrix transformation
+    directly.
+  
+  * Changed the ordering of picture drawing in PostScript and SVG
+    output so the list gets drawn from tail to head with right 
+    folds. This makes the list order of pictures match their 
+    zorder.
+  
+  * Renamed the function @withinBB@ (Core.BoundingBox) to 
+    @within@.
+  
+  * On many type signatures with e.g. Points, I\'ve changed the 
+    parameter name on the type constructor from @a@ to @u@.
+    This is to indicate that @u@ is some unit - almost always a
+    Double. e.g @Point2 a@ becomes @Point2 u@ and all the class
+    obligations change lexically as well @Floating a =>@ to 
+    @Floating u =>@. Superficially this means a lot of type 
+    signatures have diffs but haven\'t really changed. 
+  
+  * Added function @bezierCircle@ to generate the Bezier curve 
+    points for arcs describing a circle.
+  
+  * Added new demo - MultiPic. The PostScript it generates
+    is efficient - no extraneous use of @concat@. 
+  
+  * Added wumpus_default_font constant.
+  
+
+
 0.17.0 to 0.18.0:
   
   * Added instances of the affine operation classes (Scale, 
diff --git a/demo/MultiPic.hs b/demo/MultiPic.hs
new file mode 100644
--- /dev/null
+++ b/demo/MultiPic.hs
@@ -0,0 +1,33 @@
+{-# OPTIONS -Wall #-}
+
+module MultiPic where
+
+import Wumpus.Core
+import Wumpus.Core.Colour
+
+import Data.AffineSpace
+
+main :: IO ()
+main = do 
+  writeEPS_latin1 "./out/multi_pic.eps"  pic1
+  writeSVG_latin1 "./out/multi_pic.svg"  pic1
+
+
+
+pic1 :: DPicture
+pic1 = uniformScale 2 $ frameMulti $ 
+    [ ellipse blue 10 10 zeroPt
+    , ellipse red 10 10 (P2 40 40)
+    , ztextlabel "Wumpus!" (P2 40 20)
+    , square red 5 (P2 50 10)  
+    ]
+
+
+square :: (Num u, Ord u) => DRGB -> u -> Point2 u -> Primitive u
+square rgb sidelen bl = fill rgb $ vertexPath $
+    [bl, bl .+^ hvec sidelen, bl .+^ V2 sidelen sidelen, bl .+^ vvec sidelen]
+
+-- The PostScript generated from this is pretty good.
+-- 
+-- No extraneous use of @concat@.
+--
diff --git a/src/Wumpus/Core/AffineTrans.hs b/src/Wumpus/Core/AffineTrans.hs
--- a/src/Wumpus/Core/AffineTrans.hs
+++ b/src/Wumpus/Core/AffineTrans.hs
@@ -38,7 +38,8 @@
 module Wumpus.Core.AffineTrans
   ( 
   -- * Type classes
-    Rotate(..)
+    Transform(..)
+  , Rotate(..)
   , RotateAbout(..)
   , Scale(..)
   , Translate(..)
@@ -76,29 +77,41 @@
 --------------------------------------------------------------------------------
 -- Affine transformations 
 
+-- | Apply a matrix trasnformation directly.
+class Transform t where
+  transform :: u ~ DUnit t => Matrix3'3 u -> t -> t
 
+
+
 -- | Type class for rotation.
+-- 
 class Rotate t where
   rotate :: Radian -> t -> t
 
+instance Num u => Transform (Point2 u) where
+  transform ctm = (ctm *#)
 
-instance (Floating a, Real a) => Rotate (Point2 a) where
+instance Num u => Transform (Vec2 u) where
+  transform ctm = (ctm *#)
+
+
+instance (Floating u, Real u) => Rotate (Point2 u) where
   rotate a = ((rotationMatrix a) *#)
 
-instance (Floating a, Real a) => Rotate (Vec2 a) where
+instance (Floating u, Real u) => Rotate (Vec2 u) where
   rotate a = ((rotationMatrix a) *#)
 
 
 -- | Type class for rotation about a point.
 class RotateAbout t where
-  rotateAbout :: Radian -> Point2 (DUnit t) -> t -> t 
+  rotateAbout :: u ~ DUnit t =>  Radian -> Point2 u -> t -> t 
 
 
-instance (Floating a, Real a) => RotateAbout (Point2 a) where
+instance (Floating u, Real u) => RotateAbout (Point2 u) where
   rotateAbout a pt = ((originatedRotationMatrix a pt) *#) 
 
 
-instance (Floating a, Real a) => RotateAbout (Vec2 a) where
+instance (Floating u, Real u) => RotateAbout (Vec2 u) where
   rotateAbout a pt = ((originatedRotationMatrix a pt) *#) 
   
 --------------------------------------------------------------------------------
@@ -106,7 +119,7 @@
 
 -- | Type class for scaling.
 class Scale t where
-  scale :: DUnit t -> DUnit t -> t -> t
+  scale :: u ~ DUnit t => u -> u -> t -> t
 
 instance Num u => Scale (Point2 u) where
   scale x y = ((scalingMatrix x y) *#) 
diff --git a/src/Wumpus/Core/BoundingBox.hs b/src/Wumpus/Core/BoundingBox.hs
--- a/src/Wumpus/Core/BoundingBox.hs
+++ b/src/Wumpus/Core/BoundingBox.hs
@@ -40,7 +40,7 @@
   , retrace
 
   , corners
-  , withinBB
+  , within
   , boundaryWidth
   , boundaryHeight
   , boundaryBottomLeft
@@ -57,7 +57,6 @@
 
 import Wumpus.Core.AffineTrans
 import Wumpus.Core.Geometry
-import Wumpus.Core.Utils ( CMinMax(..), within )
 
 import Data.Semigroup
 
@@ -72,9 +71,9 @@
 -- spared the obligation to be /empty/. BoundingBox is an instance
 -- of the Semigroup class where @append@ is the union operation.
 -- 
-data BoundingBox a = BBox 
-      { ll_corner :: Point2 a
-      , ur_corner :: Point2 a 
+data BoundingBox u = BBox 
+      { ll_corner :: Point2 u
+      , ur_corner :: Point2 u 
       }
   deriving (Eq,Show)
 
@@ -87,11 +86,11 @@
 
 -- BBox is NOT monoidal - it\'s much simpler that way.
 
-instance Ord a => Semigroup (BoundingBox a) where
+instance Ord u => Semigroup (BoundingBox u) where
   append = union
 
 
-instance Pretty a => Pretty (BoundingBox a) where
+instance Pretty u => Pretty (BoundingBox u) where
   pretty (BBox p0 p1) = text "|_" <+> pretty p0 <+> pretty p1 <+> text "_|" 
 
 
@@ -113,14 +112,14 @@
 -- Picture, Path etc.
 --
 class Boundary a where
-  boundary :: a -> BoundingBox (DUnit a)
+  boundary :: DUnit a ~ u => a -> BoundingBox u 
 
 
 --------------------------------------------------------------------------------
 
 
-instance Pointwise (BoundingBox a) where
-  type Pt (BoundingBox a) = Point2 a
+instance Pointwise (BoundingBox u) where
+  type Pt (BoundingBox u) = Point2 u
   pointwise f (BBox bl tr) = BBox (f bl) (f tr)
 
 
@@ -132,7 +131,7 @@
 -- @bbox@ throws an error if the width or height of the 
 -- constructed bounding box is negative.
 --
-bbox :: Ord a => Point2 a -> Point2 a -> BoundingBox a
+bbox :: Ord u => Point2 u -> Point2 u -> BoundingBox u
 bbox ll@(P2 x0 y0) ur@(P2 x1 y1) 
    | x0 <= x1 && y0 <= y1 = BBox ll ur 
    | otherwise            = error "Wumpus.Core.BoundingBox.bbox - malformed."
@@ -141,15 +140,15 @@
 -- | Create a BoundingBox with bottom left corner at the origin,
 -- and dimensions @w@ and @h@.
 --
-obbox :: Num a => a -> a -> BoundingBox a
+obbox :: Num u => u -> u -> BoundingBox u
 obbox w h = BBox zeroPt (P2 w h)
 
 
 -- | The union of two bounding boxes. This is also the @append@ 
 -- of BoundingBox\'s @Semigroup@ instance.
 --
-union :: Ord a => BoundingBox a -> BoundingBox a -> BoundingBox a
-BBox ll ur `union` BBox ll' ur' = BBox (cmin ll ll') (cmax ur ur')
+union :: Ord u => BoundingBox u -> BoundingBox u -> BoundingBox u
+BBox ll ur `union` BBox ll' ur' = BBox (minPt ll ll') (maxPt ur ur')
 
 -- | Trace a list of points, retuning the BoundingBox that 
 -- includes them.
@@ -157,8 +156,8 @@
 -- 'trace' throws a run-time error when supplied with the empty 
 -- list.
 --
-trace :: (Num a, Ord a) => [Point2 a] -> BoundingBox a
-trace (p:ps) = uncurry BBox $ foldr (\z (a,b) -> (cmin z a, cmax z b) ) (p,p) ps
+trace :: (Num u, Ord u) => [Point2 u] -> BoundingBox u
+trace (p:ps) = uncurry BBox $ foldr (\z (a,b) -> (minPt z a, maxPt z b) ) (p,p) ps
 trace []     = error $ "BoundingBox.trace called in empty list"
 
 -- | Perform the supplied transformation on the four corners of 
@@ -177,24 +176,24 @@
 
 -- | Generate all the corners of a bounding box, counter-clock 
 -- wise from the bottom left, i.e. @(bl, br, tr, tl)@.
-corners :: BoundingBox a -> (Point2 a, Point2 a, Point2 a, Point2 a)
+corners :: BoundingBox u -> (Point2 u, Point2 u, Point2 u, Point2 u)
 corners (BBox bl@(P2 x0 y0) tr@(P2 x1 y1)) = (bl, br, tr, tl) where
     br = P2 x1 y0
     tl = P2 x0 y1
 
 -- | Within test - is the supplied point within the bounding box?
 --
-withinBB :: Ord a => Point2 a -> BoundingBox a -> Bool
-withinBB p (BBox ll ur) = within p ll ur
+within :: Ord u => Point2 u -> BoundingBox u -> Bool
+within p (BBox ll ur) = (minPt p ll) == ll && (maxPt p ur) == ur
 
 -- | Extract the width of a bounding box.
 --
-boundaryWidth :: Num a => BoundingBox a -> a
+boundaryWidth :: Num u => BoundingBox u -> u
 boundaryWidth (BBox (P2 xmin _) (P2 xmax _)) = xmax - xmin
 
 -- | Extract the height of a bounding box.
 --
-boundaryHeight :: Num a => BoundingBox a -> a
+boundaryHeight :: Num u => BoundingBox u -> u
 boundaryHeight (BBox (P2 _ ymin) (P2 _ ymax)) = ymax - ymin
 
 
@@ -203,19 +202,19 @@
 -- Points on the boundary
 
 -- | Extract the bottom-left corner of the bounding box.
-boundaryBottomLeft  :: BoundingBox a -> Point2 a
+boundaryBottomLeft  :: BoundingBox u -> Point2 u
 boundaryBottomLeft (BBox p0 _ ) = p0
 
 -- | Extract the top-right corner of the bounding box.
-boundaryTopRight :: BoundingBox a -> Point2 a
+boundaryTopRight :: BoundingBox u -> Point2 u
 boundaryTopRight (BBox _ p1) = p1
 
 -- | Extract the top-left corner of the bounding box.
-boundaryTopLeft :: BoundingBox a -> Point2 a
+boundaryTopLeft :: BoundingBox u -> Point2 u
 boundaryTopLeft (BBox (P2 x _) (P2 _ y)) = P2 x y
 
 -- | Extract the bottom-right corner of the bounding box.
-boundaryBottomRight :: BoundingBox a -> Point2 a
+boundaryBottomRight :: BoundingBox u -> Point2 u
 boundaryBottomRight (BBox (P2 _ y) (P2 x _)) = P2 x y
 
 
@@ -228,19 +227,19 @@
 -- Are these really worthwhile ? ...
 
 -- | Extract the unit of the left vertical plane.
-leftPlane :: BoundingBox a -> a
+leftPlane :: BoundingBox u -> u
 leftPlane (BBox (P2 l _) _) = l
 
 -- | Extract the unit of the right vertical plane.
-rightPlane :: BoundingBox a -> a
+rightPlane :: BoundingBox u -> u
 rightPlane (BBox _ (P2 r _)) = r
 
 -- | Extract the unit of the lower horizontal plane.
-lowerPlane :: BoundingBox a -> a
+lowerPlane :: BoundingBox u -> u
 lowerPlane (BBox (P2 _ l) _) = l
 
 -- | Extract the unit of the upper horizontal plane.
-upperPlane :: BoundingBox a -> a
+upperPlane :: BoundingBox u -> u
 upperPlane (BBox _ (P2 _ u)) = u
 
 
diff --git a/src/Wumpus/Core/Geometry.hs b/src/Wumpus/Core/Geometry.hs
--- a/src/Wumpus/Core/Geometry.hs
+++ b/src/Wumpus/Core/Geometry.hs
@@ -58,6 +58,8 @@
 
   -- * Point operations
   , zeroPt
+  , minPt
+  , maxPt
   , langle
 
   -- * Frame operations
@@ -91,10 +93,11 @@
 
   -- * Bezier curves
   , bezierArc
+  , bezierCircle
 
   ) where
 
-import Wumpus.Core.Utils ( CMinMax(..), PSUnit(..), oo )
+import Wumpus.Core.Utils ( PSUnit(..), oo )
 
 
 import Data.AffineSpace
@@ -117,16 +120,18 @@
 -- Datatypes 
 
 -- | 2D Vector - both components are strict.
-data Vec2 a = V2 !a !a
+--
+data Vec2 u = V2 !u !u
   deriving (Eq,Show)
 
 type DVec2 = Vec2 Double
 
 -- | 2D Point - both components are strict.
 -- 
--- Point2 derives Ord so it can be used as a key in Data.Map etc.
+-- Note - Point2 derives Ord so it can be used as a key in 
+-- Data.Map etc.
 --
-data Point2 a = P2 !a !a
+data Point2 u = P2 !u !u
   deriving (Eq,Ord,Show)
 
 type DPoint2 = Point2 Double
@@ -143,7 +148,7 @@
 -- > Frame2 (V2 e0x e0y) (V2 e1x e1y) (P2 ox oy)
 -- 
 
-data Frame2 a = Frame2 (Vec2 a) (Vec2 a) (Point2 a)
+data Frame2 u = Frame2 (Vec2 u) (Vec2 u) (Point2 u)
   deriving (Eq,Show)
 
 type DFrame2 = Frame2 Double
@@ -184,7 +189,7 @@
 -- 
 
 
-data Matrix3'3 a = M3'3 !a !a !a  !a !a !a  !a !a !a
+data Matrix3'3 u = M3'3 !u !u !u  !u !u !u  !u !u !u
   deriving (Eq)
 
 type DMatrix3'3 = Matrix3'3 Double
@@ -201,19 +206,19 @@
 --------------------------------------------------------------------------------
 -- Family instances
 
-type instance DUnit (Point2 a)    = a
-type instance DUnit (Vec2 a)      = a
-type instance DUnit (Frame2 a)    = a
-type instance DUnit (Matrix3'3 a) = a
+type instance DUnit (Point2 u)    = u
+type instance DUnit (Vec2 u)      = u
+type instance DUnit (Frame2 u)    = u
+type instance DUnit (Matrix3'3 u) = u
 
 --------------------------------------------------------------------------------
 -- lifters / convertors
 
-lift2Vec2 :: (a -> a -> a) -> Vec2 a -> Vec2 a -> Vec2 a
+lift2Vec2 :: (u -> u -> u) -> Vec2 u -> Vec2 u -> Vec2 u
 lift2Vec2 op (V2 x y) (V2 x' y') = V2 (x `op` x') (y `op` y')
 
 
-lift2Matrix3'3 :: (a -> a -> a) -> Matrix3'3 a -> Matrix3'3 a -> Matrix3'3 a
+lift2Matrix3'3 :: (u -> u -> u) -> Matrix3'3 u -> Matrix3'3 u -> Matrix3'3 u
 lift2Matrix3'3 op (M3'3 a b c d e f g h i) (M3'3 m n o p q r s t u) = 
       M3'3 (a `op` m) (b `op` n) (c `op` o)  
            (d `op` p) (e `op` q) (f `op` r)  
@@ -242,27 +247,27 @@
 
 -- Vectors have a sensible Monoid instance as addition, points don't
 
-instance Num a => Monoid (Vec2 a) where
+instance Num u => Monoid (Vec2 u) where
   mempty  = V2 0 0
   mappend = lift2Vec2 (+) 
 
 
 -- Affine frames also have a sensible Monoid instance
 
-instance (Num a, InnerSpace (Vec2 a)) => Monoid (Frame2 a) where
+instance (Num u, InnerSpace (Vec2 u)) => Monoid (Frame2 u) where
   mempty = ortho zeroPt
   mappend = frameProduct
 
 
 -- Show
 
-instance Show a => Show (Matrix3'3 a) where
+instance Show u => Show (Matrix3'3 u) where
   show (M3'3 a b c d e f g h i) = "(M3'3 " ++ body ++ ")" where
     body = show [[a,b,c],[d,e,f],[g,h,i]]
 
 -- Num
 
-instance Num a => Num (Matrix3'3 a) where
+instance Num u => Num (Matrix3'3 u) where
   (+) = lift2Matrix3'3 (+) 
   (-) = lift2Matrix3'3 (-)
 
@@ -290,19 +295,19 @@
 --------------------------------------------------------------------------------
 -- Pretty printing
 
-instance Pretty a => Pretty (Vec2 a) where
+instance Pretty u => Pretty (Vec2 u) where
   pretty (V2 a b) = angles (char '|' <+> pretty a <+> pretty b <+> char '|')
 
-instance Pretty a => Pretty (Point2 a) where
+instance Pretty u => Pretty (Point2 u) where
   pretty (P2 a b) = brackets (char '|' <+> pretty a <+> pretty b <+> char '|')
 
-instance Pretty a => Pretty (Frame2 a) where
+instance Pretty u => Pretty (Frame2 u) where
   pretty (Frame2 e0 e1 o) = braces $
         text "e0:" <> pretty e0
     <+> text "e1:" <> pretty e1
     <+> text "o:" <> pretty o
 
-instance PSUnit a => Pretty (Matrix3'3 a) where
+instance PSUnit u => Pretty (Matrix3'3 u) where
   pretty (M3'3 a b c  d e f  g h i) = 
       matline a b c <$> matline d e f <$> matline g h i
     where
@@ -317,38 +322,38 @@
 --------------------------------------------------------------------------------
 -- Vector space instances
 
-instance Num a => AdditiveGroup (Vec2 a) where
+instance Num u => AdditiveGroup (Vec2 u) where
   zeroV = V2 0 0 
   (^+^) = lift2Vec2 (+)  
   negateV = fmap negate 
 
 
-instance Num a => VectorSpace (Vec2 a) where
-  type Scalar (Vec2 a) = a
+instance Num u => VectorSpace (Vec2 u) where
+  type Scalar (Vec2 u) = u
   s *^ v = fmap (s*) v
 
 
 -- scalar (dot / inner) product via the class InnerSpace
 
-instance (Num a, InnerSpace a, Scalar a ~ a) 
-    => InnerSpace (Vec2 a) where
+instance (Num u, InnerSpace u, Scalar u ~ u) 
+    => InnerSpace (Vec2 u) where
   (V2 a b) <.> (V2 a' b') = (a <.> a') ^+^ (b <.> b')
 
 
-instance Num a => AffineSpace (Point2 a) where
-  type Diff (Point2 a) = Vec2 a
+instance Num u => AffineSpace (Point2 u) where
+  type Diff (Point2 u) = Vec2 u
   (P2 a b) .-. (P2 x y)   = V2 (a-x)  (b-y)
   (P2 a b) .+^ (V2 vx vy) = P2 (a+vx) (b+vy)
 
 
-instance Num a => AdditiveGroup (Matrix3'3 a) where
+instance Num u => AdditiveGroup (Matrix3'3 u) where
   zeroV = fromInteger 0
   (^+^) = (+)
   negateV = negate
 
 
-instance Num a => VectorSpace (Matrix3'3 a) where
-  type Scalar (Matrix3'3 a) = a
+instance Num u => VectorSpace (Matrix3'3 u) where
+  type Scalar (Matrix3'3 u) = u
   s *^ m = fmap (s*) m 
 
 --------------------------------------------------------------------------------
@@ -371,20 +376,15 @@
   type Pt [a] = Pt a
   pointwise f pts = map (pointwise f) pts 
 
-instance Pointwise (Vec2 a) where
-  type Pt (Vec2 a) = Vec2 a
+instance Pointwise (Vec2 u) where
+  type Pt (Vec2 u) = Vec2 u
   pointwise f v = f v
 
-instance Pointwise (Point2 a) where
-  type Pt (Point2 a) = Point2 a
+instance Pointwise (Point2 u) where
+  type Pt (Point2 u) = Point2 u
   pointwise f pt = f pt
 
---------------------------------------------------------------------------------
 
-instance Ord a => CMinMax (Point2 a) where
-  cmin (P2 x y) (P2 x' y') = P2 (min x x') (min y y')
-  cmax (P2 x y) (P2 x' y') = P2 (max x x') (max y y')
-
 --------------------------------------------------------------------------------
 -- Matrix multiply
 
@@ -394,14 +394,14 @@
 -- represented as homogeneous coordinates. 
 --
 class MatrixMult t where 
-  (*#) :: DUnit t ~ a => Matrix3'3 a -> t -> t
+  (*#) :: DUnit t ~ u => Matrix3'3 u -> t -> t
 
 
-instance Num a => MatrixMult (Vec2 a) where       
+instance Num u => MatrixMult (Vec2 u) where       
   (M3'3 a b c d e f _ _ _) *# (V2 m n) = V2 (a*m+b*n+c*0) (d*m+e*n+f*0)
 
 
-instance Num a => MatrixMult (Point2 a) where
+instance Num u => MatrixMult (Point2 u) where
   (M3'3 a b c d e f _ _ _) *# (P2 m n) = P2 (a*m+b*n+c*1) (d*m+e*n+f*1)
 
 --------------------------------------------------------------------------------
@@ -411,19 +411,22 @@
 -- | Direction of a vector - i.e. the counter-clockwise angle 
 -- from the x-axis.
 --
-direction :: (Floating a, Real a) => Vec2 a -> Radian
+direction :: (Floating u, Real u) => Vec2 u -> Radian
 direction (V2 x y) = langle (P2 0 0) (P2 x y)
 
 -- | Construct a vector with horizontal displacement.
-hvec :: Num a => a -> Vec2 a
+--
+hvec :: Num u => u -> Vec2 u
 hvec d = V2 d 0
 
 -- | Construct a vector with vertical displacement.
-vvec :: Num a => a -> Vec2 a
+--
+vvec :: Num u => u -> Vec2 u
 vvec d = V2 0 d
 
 -- | Construct a vector from an angle and magnitude.
-avec :: Floating a => Radian -> a -> Vec2 a
+--
+avec :: Floating u => Radian -> u -> Vec2 u
 avec theta d = V2 x y where
   ang = fromRadian theta
   x   = d * cos ang
@@ -434,25 +437,50 @@
 --
 -- > pvec = flip (.-.)
 --
-pvec :: Num a => Point2 a -> Point2 a -> Vec2 a
+pvec :: Num u => Point2 u -> Point2 u -> Vec2 u
 pvec = flip (.-.)
 
 -- | Extract the angle between two vectors.
 --
-vangle :: (Floating a, Real a, InnerSpace (Vec2 a)) 
-       => Vec2 a -> Vec2 a -> Radian
+vangle :: (Floating u, Real u, InnerSpace (Vec2 u)) 
+       => Vec2 u -> Vec2 u -> Radian
 vangle u v = realToFrac $ acos $ (u <.> v) / (on (*) magnitude u v)
 
 --------------------------------------------------------------------------------
 -- Points
 
 -- | Construct a point at 0 0.
-zeroPt :: Num a => Point2 a
+--
+zeroPt :: Num u => Point2 u
 zeroPt = P2 0 0
 
+
+-- | /Component-wise/ min on points.  
+-- Standard 'min' and 'max' via Ord are defined lexographically
+-- on pairs, e.g.:
+-- 
+-- > min (1,2) (2,1) = (1,2)
+-- 
+-- For Points we want the component-wise min and max, e.g:
+--
+-- > minPt (P2 1 2) (Pt 2 1) = Pt 1 1 
+-- > maxPt (P2 1 2) (Pt 2 1) = Pt 2 2
+-- 
+minPt :: Ord u => Point2 u -> Point2 u -> Point2 u
+minPt (P2 x y) (P2 x' y') = P2 (min x x') (min y y')
+
+-- | /Component-wise/ max on points.  
+--
+-- > maxPt (P2 1 2) (Pt 2 1) = Pt 2 2
+-- 
+maxPt :: Ord u => Point2 u -> Point2 u -> Point2 u
+maxPt (P2 x y) (P2 x' y') = P2 (max x x') (max y y')
+
+
 -- | Calculate the counter-clockwise angle between two points 
 -- and the x-axis.
-langle :: (Floating a, Real a) => Point2 a -> Point2 a -> Radian
+--
+langle :: (Floating u, Real u) => Point2 u -> Point2 u -> Radian
 langle (P2 x1 y1) (P2 x2 y2) = step (x2 - x1) (y2 - y1)
   where
     -- north-east quadrant 
@@ -476,16 +504,19 @@
 
 -- | Create a frame with standard (orthonormal bases) at the 
 -- supplied point.
-ortho :: Num a => Point2 a -> Frame2 a
+--
+ortho :: Num u => Point2 u -> Frame2 u
 ortho o = Frame2 (V2 1 0) (V2 0 1) o
 
 -- | Displace the origin of the frame by the supplied vector.
-displaceOrigin :: Num a => Vec2 a -> Frame2 a -> Frame2 a
+--
+displaceOrigin :: Num u => Vec2 u -> Frame2 u -> Frame2 u
 displaceOrigin v (Frame2 e0 e1 o) = Frame2 e0 e1 (o.+^v)
 
 -- | \'World coordinate\' calculation of a point in the supplied
 -- frame.
-pointInFrame :: Num a => Point2 a -> Frame2 a -> Point2 a
+--
+pointInFrame :: Num u => Point2 u -> Frame2 u -> Point2 u
 pointInFrame (P2 x y) (Frame2 vx vy o) = (o .+^ (vx ^* x)) .+^ (vy ^* y)  
 
 -- | Concatenate the elements of the frame as columns forming a
@@ -502,7 +533,7 @@
 -- >        0   0   1  )
 --
 
-frame2Matrix :: Num a =>  Frame2 a -> Matrix3'3 a
+frame2Matrix :: Num u =>  Frame2 u -> Matrix3'3 u
 frame2Matrix (Frame2 (V2 e0x e0y) (V2 e1x e1y) (P2 ox oy)) = 
     M3'3 e0x e1x ox  
          e0y e1y oy 
@@ -519,21 +550,24 @@
 --
 -- > Frame (V2 e0x e0y) (V2 e1x e1y) (P2 ox oy)
 -- 
-matrix2Frame :: Matrix3'3 a -> Frame2 a
+matrix2Frame :: Matrix3'3 u -> Frame2 u
 matrix2Frame (M3'3 e0x e1x ox 
                    e0y e1y oy
                    _   _   _ ) = Frame2 (V2 e0x e0y) (V2 e1x e1y) (P2 ox oy)
 
 
 -- | /Multiplication/ of frames to form their product.
-frameProduct :: (Num a, InnerSpace (Vec2 a)) => Frame2 a -> Frame2 a -> Frame2 a
+--
+frameProduct :: (Num u, InnerSpace (Vec2 u)) 
+             => Frame2 u -> Frame2 u -> Frame2 u
 frameProduct = matrix2Frame `oo` on (*) frame2Matrix
 
 
 
 -- | Is the origin at (0,0) and are the basis vectors orthogonal 
 -- with unit length?
-standardFrame :: Num a => Frame2 a -> Bool
+--
+standardFrame :: Num u => Frame2 u -> Bool
 standardFrame (Frame2 (V2 1 0) (V2 0 1) (P2 0 0)) = True
 standardFrame _                                   = False
 
@@ -547,7 +581,7 @@
 -- >       0 1 0
 -- >       0 0 1 )
 --
-identityMatrix :: Num a => Matrix3'3 a
+identityMatrix :: Num u => Matrix3'3 u
 identityMatrix = M3'3 1 0 0  
                       0 1 0  
                       0 0 1
@@ -560,7 +594,7 @@
 -- >       0  sy 0
 -- >       0  0  1 )
 --
-scalingMatrix :: Num a => a -> a -> Matrix3'3 a
+scalingMatrix :: Num u => u -> u -> Matrix3'3 u
 scalingMatrix sx sy = M3'3  sx 0  0   
                             0  sy 0   
                             0  0  1
@@ -571,7 +605,7 @@
 -- >       0  1  y
 -- >       0  0  1 )
 --
-translationMatrix :: Num a => a -> a -> Matrix3'3 a
+translationMatrix :: Num u => u -> u -> Matrix3'3 u
 translationMatrix x y = M3'3 1 0 x  
                              0 1 y  
                              0 0 1
@@ -582,7 +616,7 @@
 -- >       sin(a)   cos(a)  y
 -- >       0        0       1 )
 --
-rotationMatrix :: (Floating a, Real a) => Radian -> Matrix3'3 a
+rotationMatrix :: (Floating u, Real u) => Radian -> Matrix3'3 u
 rotationMatrix a = M3'3 (cos ang) (negate $ sin ang) 0 
                         (sin ang) (cos ang)          0  
                         0         0                  1
@@ -600,8 +634,8 @@
 -- (T being the translation matrix, R the rotation matrix and
 -- T^-1 the inverse of the translation matrix).
 --
-originatedRotationMatrix :: (Floating a, Real a) 
-                         => Radian -> (Point2 a) -> Matrix3'3 a
+originatedRotationMatrix :: (Floating u, Real u) 
+                         => Radian -> (Point2 u) -> Matrix3'3 u
 originatedRotationMatrix ang (P2 x y) = mT * (rotationMatrix ang) * mTinv
   where
     mT    = M3'3 1 0 x     
@@ -615,15 +649,18 @@
 
 
 -- | Invert a matrix.
-invert :: Fractional a => Matrix3'3 a -> Matrix3'3 a 
+--
+invert :: Fractional u => Matrix3'3 u -> Matrix3'3 u
 invert m = (1 / determinant m) *^ adjoint m
 
 -- | Determinant of a matrix.
-determinant :: Num a => Matrix3'3 a -> a
+--
+determinant :: Num u => Matrix3'3 u -> u
 determinant (M3'3 a b c d e f g h i) = a*e*i - a*f*h - b*d*i + b*f*g + c*d*h - c*e*g
 
 -- | Transpose a matrix.
-transpose :: Matrix3'3 a -> Matrix3'3 a
+--
+transpose :: Matrix3'3 u -> Matrix3'3 u
 transpose (M3'3 a b c 
                 d e f 
                 g h i) = M3'3 a d g  
@@ -632,23 +669,23 @@
 
 -- Helpers
 
-adjoint :: Num a => Matrix3'3 a -> Matrix3'3 a 
+adjoint :: Num u => Matrix3'3 u -> Matrix3'3 u
 adjoint = transpose . cofactor . mofm
 
 
-cofactor :: Num a => Matrix3'3 a -> Matrix3'3 a
+cofactor :: Num u => Matrix3'3 u -> Matrix3'3 u
 cofactor (M3'3 a b c  
                d e f  
                g h i) = M3'3   a  (-b)   c
                              (-d)   e  (-f)
                                g  (-h)   i
 
-mofm :: Num a => Matrix3'3 a -> Matrix3'3 a
+mofm :: Num u => Matrix3'3 u -> Matrix3'3 u
 mofm (M3'3 a b c  
                d e f  
                g h i)  = M3'3 m11 m12 m13  
                               m21 m22 m23 
-                          m31 m32 m33
+                              m31 m32 m33
   where  
     m11 = (e*i) - (f*h)
     m12 = (d*i) - (f*g)
@@ -726,5 +763,27 @@
     p1    = p0 .+^ avec (ang1 + pi/2) e
     p2    = p3 .+^ avec (ang2 - pi/2) e
     p3    = pt .+^ avec ang2 r
+
+
+-- | Make a circle from Bezier curves - @n@ is the number of 
+-- subdivsions per quadrant.
+--
+bezierCircle :: (Fractional u, Floating u) 
+             => Int -> u -> Point2 u -> [Point2 u]
+bezierCircle n radius pt = start $ subdivisions (n*4) (2*pi)
+  where
+    start (a:b:xs) = s : cp1 : cp2 : e : rest (b:xs)
+      where (s,cp1,cp2,e) = bezierArc radius a b pt
+                     
+    start _        = [] 
+
+    rest (a:b:xs)  = cp1 : cp2 : e : rest (b:xs)
+      where (_,cp1,cp2,e) = bezierArc radius a b pt 
+
+    rest _         = [] 
+
+    subdivisions i a = 0 : take i (iterate (+one) one) 
+      where  one  = a / fromIntegral i
+
 
 
diff --git a/src/Wumpus/Core/OneList.hs b/src/Wumpus/Core/OneList.hs
new file mode 100644
--- /dev/null
+++ b/src/Wumpus/Core/OneList.hs
@@ -0,0 +1,139 @@
+{-# OPTIONS -Wall #-}
+
+--------------------------------------------------------------------------------
+-- |
+-- Module      :  Wumpus.Core.OneList
+-- Copyright   :  (c) Stephen Tetley 2010
+-- License     :  BSD3
+--
+-- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
+-- Stability   :  highly unstable
+-- Portability :  GHC
+--
+-- Data type for non-empty lists.
+-- 
+-- Structurally the same as OneMany - but used for a different
+-- purpose.
+--
+--------------------------------------------------------------------------------
+
+module Wumpus.Core.OneList
+  (
+   -- OneMany
+    OneList
+  , ViewOL(..)
+
+  , one
+  , cons
+  , head
+  , viewl
+
+  , fromList
+
+  , toListF
+  , accumMapL
+  , isOne
+  , isMany
+   
+  ) where
+
+
+import Data.Semigroup           -- package: algebra
+
+import Control.Applicative
+import Data.Foldable
+import Data.Monoid
+import Data.Traversable
+
+import Prelude hiding ( head )
+
+-- type OneMany a = OneList a
+
+data OneList a = One a | Many a (OneList a)
+  deriving (Eq)
+
+data ViewOL a = OneL a | a :<< (OneList a)
+  deriving (Eq)
+
+--------------------------------------------------------------------------------
+-- Instances
+
+instance Show a => Show (OneList a) where
+  show = ('{':) . ($ []) . step where
+     step (One a)     = shows a . showChar '}'
+     step (Many a as) = shows a . showChar ',' . step as
+
+
+instance Functor OneList where
+  fmap f (One a)        = One $ f a
+  fmap f (Many a as)    = Many (f a) (fmap f as)
+
+instance Foldable OneList where
+  foldMap f (One a)     = f a
+  foldMap f (Many a as) = f a `mappend` foldMap f as
+
+  foldr f b0 = step b0 where
+    step b (One a)      = f a b
+    step b (Many a as)  = f a (step b as)
+
+  foldl f b0 = step b0 where
+    step b (One a)      = f b a
+    step b (Many a as)  = step (f b a) as
+
+
+instance Traversable OneList where
+  traverse f (One a)      = One  <$> f a
+  traverse f (Many a as)  = Many <$> f a <*> traverse f as
+
+
+instance Semigroup (OneList e) where
+  (One a)     `append` bs  = Many a bs
+  (Many a as) `append` bs  = Many a (as `append` bs)
+
+--------------------------------------------------------------------------------
+-- | Construct One.
+one :: a -> OneList a
+one = One
+
+
+-- | Prepend an element. Obviously this transforms a One to a Many.
+cons :: a -> OneList a -> OneList a
+cons a as   = Many a as
+
+-- | 'head' is total of course.
+head :: OneList a -> a
+head (One a)    = a
+head (Many a _) = a
+
+viewl :: OneList a -> ViewOL a
+viewl (One a)     = OneL a
+viewl (Many a as) = a :<< as
+
+-- | Construct Many. Not this function throws a error if the list has
+-- zero or one elements
+fromList :: [a] -> OneList a
+fromList []     = error "OneList.fromList: cannot build Many from empty list"
+fromList [a]    = One a
+fromList (a:as) = Many a (fromList as)
+
+
+toListF :: (a -> b) -> OneList a -> [b]
+toListF f = step where
+  step (One x)     = [f x]
+  step (Many x xs) = f x : step xs
+
+
+accumMapL :: (x -> st -> (y,st)) -> OneList x -> st -> (OneList y,st)
+accumMapL f (One x)     st = let (y,st') = f x st in (One y,st')
+accumMapL f (Many x xs) st = (Many y ys,st'')
+                             where (y, st')  = f x st
+                                   (ys,st'') = accumMapL f xs st'
+
+isMany :: OneList a -> Bool
+isMany (Many _ _) = True
+isMany _          = False
+
+isOne :: OneList a -> Bool
+isOne (One _)     = True
+isOne _           = False
+
diff --git a/src/Wumpus/Core/OutputPostScript.hs b/src/Wumpus/Core/OutputPostScript.hs
--- a/src/Wumpus/Core/OutputPostScript.hs
+++ b/src/Wumpus/Core/OutputPostScript.hs
@@ -41,6 +41,7 @@
 
 import MonadLib hiding ( Label )
 
+import qualified Data.Foldable as F
 
 
 
@@ -167,8 +168,8 @@
 outputPicture (PicBlank  _)             = return ()
 outputPicture (Single (fr,_) prim)      = 
     updateFrame fr $ outputPrimitive prim
-outputPicture (Picture (fr,_) ones)      = do
-    updateFrame fr $ onesmapM_ outputPicture  ones
+outputPicture (Picture (fr,_) ones)     =
+    updateFrame fr $ F.foldrM (\p _ -> outputPicture p) () ones
 outputPicture (Clip (fr,_) cp p)        = 
     updateFrame fr $ do { clipPath cp ; outputPicture p }
 
diff --git a/src/Wumpus/Core/OutputSVG.hs b/src/Wumpus/Core/OutputSVG.hs
--- a/src/Wumpus/Core/OutputSVG.hs
+++ b/src/Wumpus/Core/OutputSVG.hs
@@ -55,6 +55,7 @@
 
 import Text.XML.Light
 
+import qualified Data.Foldable as F
 
 type Clipped    = Bool
 
@@ -107,9 +108,12 @@
     return $ gElement (maybe [] return $ frameChange fr) [elt]
 
 picture c (Picture (fr,_) ones)    = do
-    es <- toListWithM (picture c) ones
+    -- Note - list in zorder, so we want to draw the tail first 
+    es <- liftM toListH $ F.foldrM fn emptyH ones
     return $ gElement (maybe [] return $ frameChange fr) es
-
+  where
+    fn e hl = picture c e >>= \a -> return $ hl `snocH` a
+  
 picture _ (Clip (fr,_) p a) = do 
    cp <- clipPath p
    e1 <- picture True a
diff --git a/src/Wumpus/Core/Picture.hs b/src/Wumpus/Core/Picture.hs
--- a/src/Wumpus/Core/Picture.hs
+++ b/src/Wumpus/Core/Picture.hs
@@ -33,6 +33,8 @@
   , vertexPath  
   , curvedPath
 
+  , wumpus_default_font
+
   -- * Constructing primitives
   , Stroke(..)
   , zostroke
@@ -67,9 +69,9 @@
 import Wumpus.Core.Colour
 import Wumpus.Core.Geometry
 import Wumpus.Core.GraphicsState
+import Wumpus.Core.OneList
 import Wumpus.Core.PictureInternal
 import Wumpus.Core.TextEncodingInternal
-import Wumpus.Core.Utils
 
 import Data.Semigroup
 
@@ -128,6 +130,9 @@
 -- | Lift a list of primitives to a composite picture, all 
 -- primitives will be located within the standard frame.
 --
+-- The order of the list maps to the zorder - the front of the
+-- list is drawn at the top.
+--
 -- This function throws an error when supplied the empty list.
 --
 frameMulti :: (Fractional u, Floating u, Ord u) 
@@ -141,12 +146,14 @@
 -- This function throws an error when supplied the empty list.
 --
 multi :: (Fractional u, Ord u) => [Picture u] -> Picture u
-multi ps = Picture (stdFrame, sconcat $ map boundary ps) ones
+multi ps = Picture (stdFrame, sconcat $ map boundary ps) $ step ps
   where 
     sconcat []      = error err_msg
     sconcat (x:xs)  = foldr append x xs
 
-    ones            = fromListErr ps err_msg
+    step [x]        = one x
+    step (x:xs)     = x `cons` step xs
+    step _          = error err_msg
 
     err_msg         = "Wumpus.Core.Picture.multi - empty list"
 
@@ -192,7 +199,19 @@
   
 
 
+-- | Constant for the default font, which is @Courier@ (aliased 
+-- to @Courier New@ for SVG).
+-- 
+-- The font size is 24 point. Note that only a handful of font 
+-- sizes are available directly to PostScript / GhostScript.
+--
+-- To get non-standard sizes, consider drawing the text and 
+-- applying a 'uniformScale'.
+--
+wumpus_default_font :: FontAttr
+wumpus_default_font = FontAttr "Courier" "Courier New" SVG_REGULAR 24
 
+
 --------------------------------------------------------------------------------
 -- Take Paths to Primitives
 
@@ -322,11 +341,7 @@
   where
     lbl = Label pt (lexLabel txt) identityMatrix
 
--- SVG seems to have an issue with /Courier/ and needs /Courier New/.
 
-default_font :: FontAttr
-default_font = FontAttr "Courier" "Courier New" SVG_REGULAR 24
-
 -- | Create a text label. The string should not contain newline
 -- or tab characters. Use 'multilabel' to create text with 
 -- multiple lines.
@@ -343,16 +358,17 @@
   textlabel :: Num u => t -> String -> Point2 u -> Primitive u
 
 
-instance TextLabel () where textlabel () = mkTextLabel psBlack default_font
+instance TextLabel () where 
+    textlabel () = mkTextLabel psBlack wumpus_default_font
 
 instance TextLabel (RGB3 Double) where
-  textlabel c = mkTextLabel (psColour c) default_font
+  textlabel c = mkTextLabel (psColour c) wumpus_default_font
 
 instance TextLabel (HSB3 Double) where
-  textlabel c = mkTextLabel (psColour c) default_font
+  textlabel c = mkTextLabel (psColour c) wumpus_default_font
 
 instance TextLabel (Gray Double) where
-  textlabel c = mkTextLabel (psColour c) default_font
+  textlabel c = mkTextLabel (psColour c) wumpus_default_font
 
 instance TextLabel FontAttr where
   textlabel a = mkTextLabel psBlack a
@@ -369,7 +385,7 @@
 -- | Create a label where the font is @Courier@, text size is 24pt
 -- and colour is black.
 ztextlabel :: Num u => String -> Point2 u -> Primitive u
-ztextlabel = mkTextLabel psBlack default_font
+ztextlabel = mkTextLabel psBlack wumpus_default_font
 
 
 
@@ -385,7 +401,7 @@
 
 
 -- | Create an ellipse, the ellipse will be filled unless the 
--- supplied attributes /imply/ a stoked ellipse, e.g.:
+-- supplied attributes /imply/ a stroked ellipse, e.g.:
 --
 -- > ellipse (LineWidth 4) zeroPt 40 40 
 --
@@ -491,7 +507,7 @@
 -- neither picture will be moved.
 --
 picOver :: (Num u, Ord u) => Picture u -> Picture u -> Picture u
-a `picOver` b = Picture (ortho zeroPt, bb) (mkList2 b a) 
+a `picOver` b = Picture (ortho zeroPt, bb) (cons b $ one a) 
   where
     bb = union (boundary a) (boundary b)
 
diff --git a/src/Wumpus/Core/PictureInternal.hs b/src/Wumpus/Core/PictureInternal.hs
--- a/src/Wumpus/Core/PictureInternal.hs
+++ b/src/Wumpus/Core/PictureInternal.hs
@@ -59,6 +59,7 @@
 import Wumpus.Core.FontSize
 import Wumpus.Core.Geometry
 import Wumpus.Core.GraphicsState
+import Wumpus.Core.OneList
 import Wumpus.Core.TextEncodingInternal
 import Wumpus.Core.Utils
 
@@ -234,12 +235,12 @@
 instance (Num u, Pretty u) => Pretty (Picture u) where
   pretty (PicBlank m)       = text "*BLANK*" <+> ppLocale m
   pretty (Single m prim)    = ppLocale m <$> indent 2 (pretty prim)
-  pretty (Picture m ones)  = 
-      ppLocale m <$> indent 2 (list $ toListWith pretty ones)
+  pretty (Picture m ones)   = 
+      ppLocale m <$> indent 2 (list $ toListF pretty ones)
 
   pretty (Clip m cpath p)   = 
       text "Clip:" <+> ppLocale m <$> indent 2 (pretty cpath)
-                                   <$> indent 2 (pretty p)
+                                  <$> indent 2 (pretty p)
 
 ppLocale :: (Num u, Pretty u) => Locale u -> Doc
 ppLocale (fr,bb) = align (ppfr <$> pretty bb) where
@@ -303,7 +304,10 @@
 type instance DUnit (Path u)        = u
 type instance DUnit (PrimEllipse u) = u
 
+instance (Num u, Ord u) => Transform (Picture u) where
+  transform ctm pic = transformPicture (transform ctm) (transform ctm) pic
 
+
 instance (Floating u, Real u) => Rotate (Picture u) where
   rotate = rotatePicture 
 
@@ -316,6 +320,18 @@
 instance (Num u, Ord u) => Translate (Picture u) where
   translate = translatePicture
 
+
+-- Primitives
+
+instance Num u => Transform (Primitive u) where
+  transform ctm (PPath   attr path) = 
+      PPath attr $ transformPath (transform ctm) path
+
+  transform ctm (PLabel   attr lbl) = PLabel attr $ transformLabel ctm lbl
+
+  transform ctm (PEllipse attr ell) = PEllipse attr $ transformEllipse ctm ell
+
+
 instance (Real u, Floating u) => Rotate (Primitive u) where
   rotate ang (PPath    attr path) = PPath    attr $ rotatePath ang path
   rotate ang (PLabel   attr lbl)  = PLabel   attr $ rotateLabel ang lbl
@@ -361,7 +377,11 @@
 translatePicture :: (Num u, Ord u) => u -> u -> Picture u -> Picture u
 translatePicture x y = transformPicture (translate x y) (translate x y)
 
-
+-- TODO - the nameing for these functions is confusing now that
+-- I've added a Transform typeclass.
+--
+-- Look to unifying the naming scheme in someway.
+--
 transformPicture :: (Num u, Ord u) 
                  => (Point2 u -> Point2 u) 
                  -> (Vec2 u -> Vec2 u) 
@@ -417,6 +437,9 @@
 
 -- Labels
 
+transformLabel :: Num u => Matrix3'3 u -> Label u -> Label u
+transformLabel m33 (Label pt txt ctm) = Label pt txt (ctm * m33)
+
 -- rotate CTM and pt or just CTM ??
 rotateLabel :: (Real u, Floating u) => Radian -> Label u -> Label u
 rotateLabel ang (Label pt txt ctm) = Label pt txt (ctm * rotationMatrix ang)
@@ -437,6 +460,10 @@
 
 -- 
 
+transformEllipse :: Num u => Matrix3'3 u -> PrimEllipse u -> PrimEllipse u
+transformEllipse m33 (PrimEllipse pt hw hh ctm) = 
+    PrimEllipse pt hw hh (ctm * m33)
+
 rotateEllipse :: (Real u, Floating u) 
               => Radian -> PrimEllipse u -> PrimEllipse u
 rotateEllipse ang (PrimEllipse pt hw hh ctm) = 
@@ -569,19 +596,14 @@
 --
 ellipseControlPoints :: (Floating u, Ord u)
                      => PrimEllipse u -> [Point2 u]
-ellipseControlPoints (PrimEllipse ctr hw hh ctm) = 
-    map (new_mtrx *#) $ start circ
+ellipseControlPoints (PrimEllipse ctr hw hh ctm) = map (new_mtrx *#) circ
   where
     (radius,(dx,dy)) = circleScalingProps hw hh
     new_mtrx         = ctm * scalingMatrix dx dy
-    circ             = bezierCircle radius ctr
-    
-    start ((a,b,c,d):xs)  = a:b:c:d : rest xs
-    start _               = []      -- should be unreachable
-    
-    rest  ((_,b,c,d):xs)  = b:c:d : rest xs
-    rest  _               = []
+    circ             = bezierCircle 1 radius ctr
 
+    -- subdivide the bezierCircle with 1 to get two
+    -- control points per quadrant.    
 
 
 --
@@ -598,16 +620,5 @@
     (dx,dy)    = if radius == hw then (1, rescale (0,hw) (0,1) hh)
                                  else (rescale (0,hh) (0,1) hw, 1)
 
-
-
--- | Make a circle from Bezier curves - @n@ is the number of 
--- subdivsions per quadrant.
---
-bezierCircle :: Floating u 
-             => u -> Point2 u -> [(Point2 u, Point2 u, Point2 u, Point2 u)]
-bezierCircle radius pt = map mkQuad angs
-  where
-    angs         = [(0, pi*0.5), (pi*0.5,pi), (pi, pi*1.5), (pi*1.5, pi*2)]
-    mkQuad (a,b) = bezierArc radius a b pt
 
 
diff --git a/src/Wumpus/Core/Utils.hs b/src/Wumpus/Core/Utils.hs
--- a/src/Wumpus/Core/Utils.hs
+++ b/src/Wumpus/Core/Utils.hs
@@ -19,12 +19,9 @@
 module Wumpus.Core.Utils
   ( 
 
-  -- * Component-wise min and max
-    CMinMax(..)
-  , within
 
   -- * Three values  
-  , max3
+    max3
   , min3
   , med3
 
@@ -55,16 +52,9 @@
 
   -- * Hughes list
   , H
+  , emptyH
   , toListH
-  
-
-  -- * OneList type - non-empty list type
-  , OneList(..)
-  , mkList2
-  , onesmapM_
-  , toListWith
-  , toListWithM
-  , fromListErr
+  , snocH  
 
 
   -- * specs etc. from Data.Aviary
@@ -80,7 +70,6 @@
 
 
 import Control.Applicative
-import Control.Monad ( ap )
 import Data.List ( intersperse )
 import Data.Ratio
 import Data.Time
@@ -89,35 +78,7 @@
 
 --------------------------------------------------------------------------------
 
--- | /Component-wise/ min and max. 
--- Standard 'min' and 'max' via Ord are defined lexographically
--- on pairs, e.g.:
--- 
--- > min (1,2) (2,1) = (1,2)
--- 
--- For certain geometrical objects (Points!) we want the 
--- (constructed-) componentwise min and max, e.g:
---
--- > cmin (1,2) (2,1) = (1,1) 
--- > cmax (1,2) (2,1) = (2,2)
--- 
 
-class CMinMax a where
-  cmin :: a -> a -> a
-  cmax :: a -> a -> a
-
-
-
-instance (Ord a, Ord b) => CMinMax (a,b) where
-  cmin (x,y) (x',y') = (min x x', min y y')
-  cmax (x,y) (x',y') = (max x x', max y y')
-
-
--- | Test whether a is within opper and lower.
-within :: Eq a => CMinMax a => a -> a -> a -> Bool
-within a lower upper = (cmin a lower) == lower && (cmax a upper) == upper
-
-
 -- | max of 3
 max3 :: Ord a => a -> a -> a -> a
 max3 a b c = max (max a b) c
@@ -265,52 +226,16 @@
 
 type H a = [a] -> [a]
 
+emptyH :: H a
+emptyH = id
+
 toListH :: H a -> [a]
 toListH = ($ [])
 
---------------------------------------------------------------------------------
-
-infixr 5 `Many`
-
-data OneList a = One a | Many a  (OneList a)
-  deriving (Eq)
-
-instance Show a => Show (OneList a) where
-  show = ('{':) . ($ []) . step where
-     step (One a)     = shows a . showChar '}'
-     step (Many a xs) = shows a . showChar ',' . step xs
-
-
-mkList2 :: a -> a -> OneList a
-mkList2 a b = a `Many` One b
-
-
-onesmapM_ :: Monad m => (a -> m b) -> OneList a -> m ()
-onesmapM_ f (One x)     = f x >> return ()
-onesmapM_ f (Many x xs) = f x >> onesmapM_ f xs
-
-toListWith :: (a -> b) -> OneList a -> [b]
-toListWith f (One x)     = [f x]
-toListWith f (Many x xs) = f x : toListWith f xs
-
-toListWithM :: Monad m => (a -> m b) -> OneList a -> m [b]
-toListWithM mf (One x)     = mf x >>= \a -> return [a]
-toListWithM mf (Many x xs) = return (:) `ap` mf x `ap` toListWithM mf xs
-
-
--- Error msg is a parameter, so client code can supply a 
--- meaningful warning.
--- 
-fromListErr :: [a] -> String -> OneList a
-fromListErr xs0 msg = step xs0 where
-   step []     = error msg
-   step [a]    = One a
-   step (a:xs) = Many a $ step xs
-
-
+snocH :: H a -> a -> H a
+snocH hl a = hl . (a:)
 
 --------------------------------------------------------------------------------
-
 
 -- | A variant of the @D2@ or dovekie combinator - the argument
 -- order has been changed to be more satisfying for Haskellers:
diff --git a/src/Wumpus/Core/VersionNumber.hs b/src/Wumpus/Core/VersionNumber.hs
--- a/src/Wumpus/Core/VersionNumber.hs
+++ b/src/Wumpus/Core/VersionNumber.hs
@@ -22,4 +22,4 @@
 
 
 wumpus_core_version :: (Int,Int,Int)
-wumpus_core_version = (0,18,0)
+wumpus_core_version = (0,19,0)
diff --git a/src/Wumpus/Extra/SVGColours.hs b/src/Wumpus/Extra/SVGColours.hs
--- a/src/Wumpus/Extra/SVGColours.hs
+++ b/src/Wumpus/Extra/SVGColours.hs
@@ -172,7 +172,7 @@
 import Wumpus.Core.Colour ( RGB3(..), DRGB )
 
 
-import Prelude hiding ( tan )
+import Prelude ( )
   
 
 
diff --git a/wumpus-core.cabal b/wumpus-core.cabal
--- a/wumpus-core.cabal
+++ b/wumpus-core.cabal
@@ -1,5 +1,5 @@
 name:             wumpus-core
-version:          0.18.0
+version:          0.19.0
 license:          BSD3
 license-file:     LICENSE
 copyright:        Stephen Tetley <stephen.tetley@gmail.com>
@@ -16,7 +16,7 @@
   It can generate PostScript (EPS) files and SVG files. The 
   generated PostScript code is plain [1] and reasonably 
   efficient as the use of stack operations, i.e @gsave@ and 
-  @grestore@ is minimized.
+  @grestore@, is minimized.
   .
   Pictures in Wumpus are made from /paths/ and text /labels/. 
   Paths themselves are made from points. The usual affine 
@@ -25,35 +25,34 @@
   is no notion of a current point, Wumpus builds pictures in a
   coordinate-free style. 
   .
-  With recent revisions, I\'ve added some extra helper modules
-  that are not really part of the \"core\", but they provide 
-  lists of named colours and /safe/ fonts, plus some code  
-  (Extra.PictureLanguage) that has been moved out of the
-  wumpus-core namespace because it is somewhat \"higher-level\". 
+  Wumpus-core includes some extra helper modules that are not 
+  really part of the \"core\", but are otherwise currently 
+  homeless. They provide lists of named colours and /safe/ 
+  fonts, plus some prototype code (Extra.PictureLanguage) for 
+  arranging pictures.
   .
   WARNING...
   .
-  With revision 0.18.0, I\'ve changed the internals a bit so that 
-  Primitives (paths, text labels) support affine transformations. 
-  In the end, this didn\'t changed the API significantly, though 
-  with the next revision, I want to look at changing the 
-  PostScript output - swapping some uses of @concat@ to @moveto@; 
-  so again there is the possibility of significant changes 
-  between this revision and the next one.
+  The modules @Core.BoundingBox@ and @Extra.PictureLanguage@ are
+  likely to be reworked significantly in the future. 
   .
-  Also the module, Core.BoundingBox, is still a candidate for 
-  reworking, as it has too many functions that do not offer 
+  @Core.BoundingBox@ has too many functions that do not offer 
   distinct functionality. Some functions were removed in 
   revision 0.17.0 and some more are likely to follow. 
   .
+  @Extra.PictureLanguage@ needs some more thought. The current 
+  set of classes is rather cumbersome, and some of the operations 
+  would benefit new names.
+  .
   NOTE...
   .
-  One consequence of adding affine transformations for primitives
-  is that the bounding box of a primitive under transformation 
-  may be tighter than than the bounding box of transformed 
-  picture containing the same primitive, i.e.:
+  Revision 0.17.0 added affine transformations for primitives 
+  (paths, text labels, ellipses), one consequence of this is 
+  the bounding box may be tighter for a primitive under affine 
+  transformation then lifted to a picture, than a primitive 
+  lifted to picture then transformed, i.e.:
   . 
-  @liftToPicture (transform PRIM) /= transform (liftToPicture PRIM)@
+  @boundary (liftToPicture (transform PRIM)) /= boundary (transform (liftToPicture PRIM))@
   .
   Where liftToPicture is usually @frame@ from 
   @Wumpus.Core.Picture@.
@@ -72,22 +71,52 @@
   found at <http://code.google.com/p/copperbox/> though.
   .
   Some of the design decisions made for wumpus-core are not 
-  sophisticated (e.g. how attributes like colour are 
-  handled, and how the bounding boxes of text labels are 
-  calculated), so Wumpus might be limited compared to other 
-  systems. However, the design permits a simple implementation - 
-  which is a priority. Text encoding an exception - I\'m not 
-  sure how reasonable the design is. The current implementation 
+  sophisticated (e.g. how attributes like colour are handled, 
+  and how the bounding boxes of text labels are calculated), so 
+  Wumpus might be limited compared to other systems. However, 
+  the design permits a fairly simple implementation - which is 
+  a priority. Text encoding an exception - I\'m not sure how 
+  reasonable the design is. The current implementation 
   appears okay for Latin 1 but may be inadequate for other 
   character sets, so I may have to revise it significantly.
   .
   .
   \[1\] Because the output is simple, straight-line PostScript 
-  code, it is possible to use GraphicsMagick or a similar tool to 
-  convert Wumpus'\s EPS files to many other formats (bitmaps). 
+  code, it is possible to use GraphicsMagick or a similar tool 
+  to convert Wumpus'\s EPS files to many other formats 
+  (bitmaps). 
   .
   Changelog:
   .
+  0.18,0 to 0.19.0:
+  .
+  * Added @Transform@ type class to apply a matrix transformation
+    directly.
+  .
+  * Changed the ordering of picture drawing in PostScript and SVG
+    output so the list gets drawn from tail to head with right 
+    folds. This makes the list order of pictures match their 
+    zorder.
+  .
+  * Renamed the function @withinBB@ (Core.BoundingBox) to 
+    @within@.
+  .
+  * On many type signatures with e.g. Points, I\'ve changed the 
+    parameter name on the type constructor from @a@ to @u@.
+    This is to indicate that @u@ is some unit - almost always a
+    Double. e.g @Point2 a@ becomes @Point2 u@ and all the class
+    obligations change lexically as well @Floating a =>@ to 
+    @Floating u =>@. Superficially this means a lot of type 
+    signatures have diffs but haven\'t really changed. 
+  .
+  * Added function @bezierCircle@ to generate the Bezier curve 
+    points for arcs describing a circle.
+  .
+  * Added new demo - MultiPic. The PostScript it generates
+    is efficient - no extraneous use of @concat@. 
+  .
+  * Added wumpus_default_font constant.
+  .
   0.17.0 to 0.18.0:
   .
   * Added instances of the affine operation classes (Scale, 
@@ -105,7 +134,7 @@
     transformation, Pictures may generate a larger bounding box 
     than composite primitives.
   .
-  * Minor change - ztextlabal changed to use 24pt type rather 
+  * Minor change - ztextlabel changed to use 24pt type rather 
     than 12pt. 
   .
   * Corrected the cabal file to include the correct files for 
@@ -113,54 +142,7 @@
     missing with the generated file @WorldFrame.eps@ incorrectly 
     included instead.
   .
-  0.16.0 to 0.17.0:
   .
-  * Added Core.WumpusTypes to export opaque versions of
-    datatypes from Core.PictureInternal. This should make
-    the Haddock documentation more cohesive.
-  . 
-  * Moved the Core.PictureLanguage module into the Extra
-    namespace (Extra.PictureLanguage). This module may change
-    in detail, if not in spirit in the future as I'm not 
-    very happy with it. Also this module is somewhat 
-    \"higher-level\" than the modules in wumpus-core, so 
-    a different home seems fitting. 
-  . 
-  * Removed CardinalPoint and boundaryPoint from BoundingBox.
-  .
-  * Argument order of 'textlabel' and 'ztextlabel' changed so
-    that Point2 is the last argument.
-  .
-  * PathSegment constructor names changed - this is an internal
-    change as the constructors are not exported.
-  .
-  * Primitive type changed - moved Ellipse properties into 
-    PrimEllipse type - internal change.
-  .
-  * Removed dependency on \'old-time\'.
-  .
-  0.15.0 to 0.16.0:
-  .
-  * Additions to Core.Geometry (direction, pvec, vangle, 
-    circularModulo).
-  .
-  * Fixed error with langle due to not accounting for circle 
-    quadrants in Core.Geometry.
-  .
-  * Point2 now derives Ord - so it can be used as a key for
-    Data.Map.
-  .
-  * Added escape-character handling to text output in PostScript.
-    This was causing a nasty bug where a drawing would completely
-    fail when special chars shown (GhostView gives little hint of 
-    what is wrong when such errors are present).
-  . 
-  * Changed BoundingBox operation 'corners' to return a 4-tuple
-    rather than a list.
-  .  
-  * Added centeredAt to PictureLanguage
-  .
-  .
 build-type:         Simple
 stability:          unstable
 cabal-version:      >= 1.2
@@ -175,6 +157,7 @@
   demo/AffineTestBase.hs,
   demo/FontPic.hs,
   demo/LabelPic.hs,
+  demo/MultiPic.hs
   demo/Picture.hs,
   doc/Guide.pdf,
   doc-src/Guide.lhs,
@@ -214,6 +197,7 @@
     Wumpus.Core.PictureInternal,
     Wumpus.Core.PostScript,
     Wumpus.Core.SVG,
+    Wumpus.Core.OneList,
     Wumpus.Core.TextEncodingInternal,
     Wumpus.Core.Utils