diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,7 +1,7 @@
 --------------------------------------------------------------------------------
 The Disciplined Disciple Compiler License (MIT style)
 
-Copyrite (K) 2007-2012 The Disciplined Disciple Compiler Strike Force
+Copyrite (K) 2007-2013 The Disciplined Disciple Compiler Strike Force
 All rights reversed.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
diff --git a/ddc-code.cabal b/ddc-code.cabal
--- a/ddc-code.cabal
+++ b/ddc-code.cabal
@@ -1,5 +1,5 @@
 Name:           ddc-code
-Version:        0.3.1.1
+Version:        0.3.2.1
 License:        MIT
 License-file:   LICENSE
 Author:         The Disciplined Disciple Compiler Strike Force
@@ -9,7 +9,6 @@
 Stability:      experimental
 Category:       Compilers/Interpreters
 Homepage:       http://disciple.ouroborus.net
-Bug-reports:    disciple@ouroborus.net
 Synopsis:       Disciplined Disciple Compiler base libraries.
 Description:    Disciplined Disciple Compiler base libraries.
 
diff --git a/lite/base/Data/Container/List.dcl b/lite/base/Data/Container/List.dcl
--- a/lite/base/Data/Container/List.dcl
+++ b/lite/base/Data/Container/List.dcl
@@ -1,19 +1,19 @@
 module List
 imports 
  addNat 
-  ::    [r1 r2 r3 : %].
-        Nat r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Nat r1 -(Pure | Use r3)>
         Nat r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Nat r3
 
  subNat 
-  ::    [r1 r2 r3 : %].
-        Nat r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Nat r1 -(Pure | Use r3)>
         Nat r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Nat r3
 
- showInt   :: [r : %]. Nat# -> Ptr# r String#
- putStrLn  :: [r : %]. Ptr# r String# -> Void#
+ showInt   :: [r : Region]. Nat# -> Ptr# r String#
+ putStrLn  :: [r : Region]. Ptr# r String# -> Void#
 
 with letrec
 
@@ -21,7 +21,7 @@
 -- Constructors ---------------------------------------------------------------
 -- | Construct a list containing a single element.
 singleton 
-        [r : %] [a : *]
+        [r : Region] [a : Data]
         (x : a)         { Alloc r | Use r }
         : List r a
  = Cons [r] [a] x (Nil [r] [a] ())
@@ -29,8 +29,8 @@
 
 -- | Construct a list containing copies of some value.
 replicate
-        [r1 r2 : %] [a : *]
-        (n : Nat r1)            { !0 | Use r1 + Use r2 }
+        [r1 r2 : Region] [a : Data]
+        (n : Nat r1)            { Pure | Use r1 + Use r2 }
         (x : a)                 { Read r1 + Read r2 + Alloc r2 | Use r1 + Use r2}
         : List r2 a
  = letregion r3 in
@@ -45,8 +45,8 @@
 
 -- | Construct a range of Nat values
 enumFromTo
-        [r1 r2 : %]
-        (n      : Nat r2)       { !0 | Use r1 + Use r2 }
+        [r1 r2  : Region]
+        (n      : Nat r2)       { Pure | Use r1 + Use r2 }
         (max    : Nat r2)       { Read r2 + Alloc r1 + Alloc r2 | Use r1 + Use r2 }
         : List r1 (Nat r2)
  = case n of
@@ -62,7 +62,7 @@
 
 
 -- | O(n^2) reverse the elements in a list.
-reverse [r1 r2 : %] [a : *]
+reverse [r1 r2 : Region] [a : Data]
         (xx : List r1 a)        { Read r1 + Read r2 + Alloc r2 | Use r1 + Use r2 }
         : List r2 a
  = case xx of
@@ -74,8 +74,8 @@
 
 
 -- | Append two lists.
-append  [r1 r2 : %] [a : *]
-        (xx : List r1 a)        { !0 | Use r1 + Use r2 }
+append  [r1 r2 : Region] [a : Data]
+        (xx : List r1 a)        { Pure | Use r1 + Use r2 }
         (yy : List r2 a)        { Read r1 + Alloc r2 | Use r1 + Use r2 + DeepUse a }
         : List r2 a
  = case xx of
@@ -88,13 +88,13 @@
 
 -------------------------------------------------------------------------------
 -- | Take the length of a list.
-length  [r1 r2 : %] [a : *]
+length  [r1 r2 : Region] [a : Data]
         (xx : List r1 a)   { Read r1 + Read r2 + Alloc r2 | Use r1 + Use r2 }
         : Nat r2
  = length2 [:r1 r2 a:] (N# [r2] 0#) xx
 
-length2 [r1 r2 : %] [a : *]
-        (acc : Nat r2)     { !0 | Use r1 + Use r2 }
+length2 [r1 r2 : Region] [a : Data]
+        (acc : Nat r2)     { Pure | Use r1 + Use r2 }
         (xx : List r1 a)   { Read r1 + Read r2 + Alloc r2 
                            | Use r1  + Use r2}
         : Nat r2
diff --git a/lite/base/Data/Numeric/Bool.dcl b/lite/base/Data/Numeric/Bool.dcl
--- a/lite/base/Data/Numeric/Bool.dcl
+++ b/lite/base/Data/Numeric/Bool.dcl
@@ -1,41 +1,41 @@
 module Bool
 exports
  boxBool
-  ::    [r : %].
+  ::    [r : Region].
         Bool# -(Alloc r | Use r)>
         Bool r
 
  unboxBool
-  ::    [r : %].
-        Bool r -(Read r | $0)>
+  ::    [r : Region].
+        Bool r -(Read r | Empty)>
         Bool#
 
  addBool
-  ::    [r1 r2 r3 : %].
-        Bool r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Bool r1 -(Pure | Use r3)>
         Bool r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Bool r3
 
  mulBool
-  ::    [r1 r2 r3 : %].
-        Bool r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Bool r1 -(Pure | Use r3)>
         Bool r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Bool r3
 
  not    
-  ::    [r1 r2 : %].
+  ::    [r1 r2 : Region].
         Bool r1 -(Read r1 + Alloc r2 | Use r1 + Use r2)>
         Bool r2
 
  and    
-  ::    [r1 r2 r3 : %].
-        Bool r1 -(!0 | Use r1 + Use r2)>
+  ::    [r1 r2 r3 : Region].
+        Bool r1 -(Pure | Use r1 + Use r2)>
         Bool r2 -(Read r1 + Alloc r2 | Use r1 + Use r2)>
         Bool r2
 
  or
-  ::    [r1 r2 r3 : %].
-        Bool r1 -(!0 | Use r1 + Use r2)>
+  ::    [r1 r2 r3 : Region].
+        Bool r1 -(Pure | Use r1 + Use r2)>
         Bool r2 -(Read r1 + Alloc r2 | Use r1 + Use r2)>
         Bool r2
 
@@ -43,23 +43,24 @@
 
 
 -- | Box a boolean.
-boxBool [r : %] 
+boxBool [r : Region] 
         (i : Bool#)     { Alloc r | Use r } 
         : Bool r
  = B# [r] i
 
 
 -- | Unbox a boolean.
-unboxBool [r : %]
-        (x : Bool r)    { Read r | $0 } 
+unboxBool 
+        [r : Region]
+        (x : Bool r)    { Read r | Empty } 
         : Bool#
  = case x of 
     B# i  -> i
 
 
 -- | Add two booleans.
-addBool [r1 r2 r3 : %] 
-        (x : Bool r1)   { !0 | Use r3 } 
+addBool [r1 r2 r3 : Region] 
+        (x : Bool r1)   { Pure | Use r3 } 
         (y : Bool r2)   { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3 }
         : Bool r3
  =  case x of { B# i1 
@@ -68,8 +69,8 @@
 
 
 -- | Multiply two naturals.
-mulBool [r1 r2 r3 : %] 
-        (x : Bool r1)   { !0 | Use r3 } 
+mulBool [r1 r2 r3 : Region] 
+        (x : Bool r1)   { Pure | Use r3 } 
         (y : Bool r2)   { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3 }
         : Bool r3
  =  case x of { B# i1 
@@ -78,7 +79,7 @@
 
 
 -- | Boolean negation.
-not     [r1 r2 : %]
+not     [r1 r2 : Region]
         (x : Bool r1)   {Read r1 + Alloc r2 | Use r1 + Use r2}
         : Bool r2
  = case unboxBool [r1] x of
@@ -87,8 +88,8 @@
 
 
 -- | Right biased short-circuiting and.
-and     [r1 r2 r3 : %]
-        (x : Bool r1)   {!0 | Use r1 + Use r2 }
+and     [r1 r2 r3 : Region]
+        (x : Bool r1)   { Pure | Use r1 + Use r2 }
         (y : Bool r2)   { Read r1 + Alloc r2 | Use r1 + Use r2 }
         : Bool r2
  = case unboxBool [r1] x of 
@@ -97,8 +98,8 @@
 
 
 -- | Right biased short-circuiting or.
-or      [r1 r2 r3 : %]
-        (x : Bool r1)   {!0 | Use r1 + Use r2 }
+or      [r1 r2 r3 : Region]
+        (x : Bool r1)   { Pure | Use r1 + Use r2 }
         (y : Bool r2)   { Read r1 + Alloc r2 | Use r1 + Use r2 }
         : Bool r2
  = case unboxBool [r1] x of 
diff --git a/lite/base/Data/Numeric/Int.dcl b/lite/base/Data/Numeric/Int.dcl
--- a/lite/base/Data/Numeric/Int.dcl
+++ b/lite/base/Data/Numeric/Int.dcl
@@ -1,30 +1,30 @@
 module Int 
 exports
  boxInt  
-  ::    [r : %].
+  ::    [r : Region].
         Int# -(Alloc r | Use r)>
         Int r
 
  unboxInt 
-  ::    [r : %].
-        Int r -(Read r | $0)>
+  ::    [r : Region].
+        Int r -(Read r | Empty)>
         Int#
 
  addInt 
-  ::    [r1 r2 r3 : %].
-        Int r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Int r1 -(Pure | Use r3)>
         Int r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Int r3
 
  subInt 
-  ::    [r1 r2 r3 : %].
-        Int r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Int r1 -(Pure | Use r3)>
         Int r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Int r3
 
  mulInt 
-  ::    [r1 r2 r3 : %].
-        Int r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Int r1 -(Pure | Use r3)>
         Int r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Int r3
 
@@ -32,23 +32,23 @@
 
 
 -- | Box an integer.
-boxInt  [r : %] 
+boxInt  [r : Region] 
         (i : Int#) { Alloc r | Use r } 
         : Int r
  = I# [r] i
 
 
 -- | Unbox an integer.
-unboxInt [r : %]
-        (x : Int r) { Read r | $0 } 
+unboxInt [r : Region]
+        (x : Int r) { Read r | Empty } 
         : Int#
  = case x of 
     I# i  -> i
 
 
 -- | Add two integers.
-addInt  [r1 r2 r3 : %] 
-        (x : Int r1) { !0 | Use r3 } 
+addInt  [r1 r2 r3 : Region] 
+        (x : Int r1) { Pure | Use r3 } 
         (y : Int r2) { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3 }
         : Int r3
  =  case x of { I# i1 
@@ -57,8 +57,8 @@
 
 
 -- | Subtract the second integer from the first.
-subInt  [r1 r2 r3 : %] 
-        (x : Int r1) { !0 | Use r3 } 
+subInt  [r1 r2 r3 : Region] 
+        (x : Int r1) { Pure | Use r3 } 
         (y : Int r2) { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3 }
         : Int r3
  =  case x of { I# i1 
@@ -67,8 +67,8 @@
 
 
 -- | Multiply two integers.
-mulInt  [r1 r2 r3 : %] 
-        (x : Int r1) { !0 | Use r3 } 
+mulInt  [r1 r2 r3 : Region] 
+        (x : Int r1) { Pure | Use r3 } 
         (y : Int r2) { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3 }
         : Int r3
  =  case x of { I# i1 
diff --git a/lite/base/Data/Numeric/Nat.dcl b/lite/base/Data/Numeric/Nat.dcl
--- a/lite/base/Data/Numeric/Nat.dcl
+++ b/lite/base/Data/Numeric/Nat.dcl
@@ -1,42 +1,42 @@
 module Nat 
 exports
  boxNat
-  ::    [r : %].
+  ::    [r : Region].
         Nat# -(Alloc r | Use r)>
         Nat r
 
  unboxNat 
-  ::    [r : %].
-        Nat r -(Read r | $0)>
+  ::    [r : Region].
+        Nat r -(Read r | Empty)>
         Nat#
 
  addNat 
-  ::    [r1 r2 r3 : %].
-        Nat r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Nat r1 -(Pure | Use r3)>
         Nat r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Nat r3
 
  subNat 
-  ::    [r1 r2 r3 : %].
-        Nat r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Nat r1 -(Pure | Use r3)>
         Nat r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Nat r3
 
  mulNat
-  ::    [r1 r2 r3 : %].
-        Nat r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Nat r1 -(Pure | Use r3)>
         Nat r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Nat r3
 
  eqNat 
-  ::    [r1 r2 r3 : %].
-        Nat r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Nat r1 -(Pure | Use r3)>
         Nat r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Bool r3
 
  neqNat 
-  ::    [r1 r2 r3 : %].
-        Nat r1 -(!0 | Use r3)>
+  ::    [r1 r2 r3 : Region].
+        Nat r1 -(Pure | Use r3)>
         Nat r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)>
         Bool r3
 
@@ -44,54 +44,54 @@
 
 
 -- | Box an natural.
-boxNat  [r : %] 
+boxNat  [r : Region] 
         (i : Nat#) { Alloc r | Use r } 
         : Nat r
  = N# [r] i
 
 
 -- | Unbox an natural.
-unboxNat [r : %]
-        (x : Nat r) { Read r | $0 } 
+unboxNat [r : Region]
+        (x : Nat r) { Read r | Empty } 
         : Nat#
  = case x of { N# n -> n }
 
 
 -- | Add two naturals.
-addNat  [r1 r2 r3 : %] 
-        (x : Nat r1) { !0 | Use r3 } 
+addNat  [r1 r2 r3 : Region] 
+        (x : Nat r1) { Pure | Use r3 } 
         (y : Nat r2) { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3 }
         : Nat r3
  =  case x of { N# i1 -> case y of { N# i2 -> N# [r3] (add# [Nat#] i1 i2) } }
 
 
 -- | Subtract the second natural from the first.
-subNat  [r1 r2 r3 : %]
-        (x : Nat r1) { !0 | Use r3 } 
+subNat  [r1 r2 r3 : Region]
+        (x : Nat r1) { Pure | Use r3 } 
         (y : Nat r2) { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3 }
         : Nat r3
  =  case x of { N# i1 -> case y of { N# i2 -> N# [r3] (sub# [Nat#] i1 i2) } }
 
 
 -- | Multiply two naturals.
-mulNat  [r1 r2 r3 : %] 
-        (x : Nat r1) { !0 | Use r3 } 
+mulNat  [r1 r2 r3 : Region] 
+        (x : Nat r1) { Pure | Use r3 } 
         (y : Nat r2) { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3 }
         : Nat r3
  =  case x of { N# i1 -> case y of { N# i2 -> N# [r3] (mul# [Nat#] i1 i2) } }
 
 
 -- | Equality on naturals.
-eqNat   [r1 r2 r3 : %]
-        (x : Nat r1) { !0 | Use r3 }
+eqNat   [r1 r2 r3 : Region]
+        (x : Nat r1) { Pure | Use r3 }
         (y : Nat r2) { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3}
         : Bool r3
  =  case x of { N# n1 -> case y of { N# n2 -> B# [r3] (eq# [Nat#] n1 n2) } }
 
 
 -- | Negated Equality on naturals.
-neqNat   [r1 r2 r3 : %]
-        (x : Nat r1) { !0 | Use r3 }
+neqNat   [r1 r2 r3 : Region]
+        (x : Nat r1) { Pure | Use r3 }
         (y : Nat r2) { Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3}
         : Bool r3
  =  case x of { N# n1 -> case y of { N# n2 -> B# [r3] (neq# [Nat#] n1 n2) } }
diff --git a/lite/base/Math/Integer.dcl b/lite/base/Math/Integer.dcl
--- a/lite/base/Math/Integer.dcl
+++ b/lite/base/Math/Integer.dcl
@@ -1,20 +1,20 @@
 
 module Integer 
 imports {
-        subInt  :: [r1 r2 r3 : %]
-                . Int r1 -(!0 | Use r3)> 
+        subInt  :: [r1 r2 r3 : Region]
+                . Int r1 -(Pure | Use r3)> 
                   Int r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)> 
                   Int r3;
 
-        mulInt  :: [r1 r2 r3 : %]
-                . Int r1 -(!0 | Use r3)> 
+        mulInt  :: [r1 r2 r3 : Region]
+                . Int r1 -(Pure | Use r3)> 
                   Int r2 -(Read r1 + Read r2 + Alloc r3 | Use r1 + Use r3)> 
                   Int r3;
 }
 with letrec
 
-fac    [r : %] 
-       (acc : Int r) {!0 | Use r}
+fac    [r : Region] 
+       (acc : Int r) {Pure | Use r}
        (n   : Int r) {Read r + Alloc r | Use r} : Int r
  =  case n of { 
         I# i -> 
diff --git a/salt/primitive/Vector.dcs b/salt/primitive/Vector.dcs
--- a/salt/primitive/Vector.dcs
+++ b/salt/primitive/Vector.dcs
@@ -2,8 +2,8 @@
 -- | Vectors are arrays of unboxed values.
 module Vector
 imports {
-        allocRaw     :: [r : %]. Tag# -> Nat# -> Ptr# r Obj;
-        payloadOfRaw :: [r : %]. Ptr# r Obj -> Addr#;
+        allocRaw     :: [r : Region]. Tag# -> Nat# -> Ptr# r Obj;
+        payloadOfRaw :: [r : Region]. Ptr# r Obj -> Addr#;
 } 
 with letrec
 
@@ -16,7 +16,7 @@
 --      uint8_t payload[] 
 --   } Vector8
 --
-allocVector8 [r : %] (length : Nat#) : Ptr# r Obj
+allocVector8 [r : Region] (length : Nat#) : Ptr# r Obj
  = do   
         -- total size of object payload.
         bytes   = add# [Nat#] (bytesNat# V#) length
@@ -34,13 +34,13 @@
 
 -- Projections ----------------------------------------------------------------
 -- | Get the length of a vector.
-lengthVector8 [r : %] (obj : Ptr# r Obj) : Nat#
+lengthVector8 [r : Region] (obj : Ptr# r Obj) : Nat#
  = do   payload = payloadOfRaw [r] obj
         read# [Nat#] payload 0#
 
 
 -- | Unsafely read a byte from a vector.
-indexVector8 [r : %] (obj : Ptr# r Obj) (index : Nat#) : Word8#
+indexVector8 [r : Region] (obj : Ptr# r Obj) (index : Nat#) : Word8#
  = do   payload = payloadOfRaw [r] obj
         offset  = add# [Nat#] (bytesNat# V#) index
         read# [Word8#] payload offset 
@@ -49,7 +49,7 @@
 -- Update ---------------------------------------------------------------------
 -- | Unsafely write a byte into a vector.
 updateVector8 
-        [r : %]
+        [r : Region]
         (obj : Ptr# r Obj)
         (index : Nat#) (val : Word8#)
         : Void#
@@ -61,7 +61,7 @@
 -- Fill -----------------------------------------------------------------------
 -- | Fill a vector with the given value.
 fillVector8 
-        [r : %]
+        [r : Region]
         (obj : Ptr# r Obj) (val : Word8#)
         : Void#
  = do   payload = payloadOfRaw [r] obj
@@ -74,7 +74,7 @@
 
 -- | Fill a range of bytes with the given value.
 fillPtr8 
-        [r : %] 
+        [r : Region] 
         (cur : Ptr# r Word8#) 
         (top : Ptr# r Word8#) (val : Word8#)
         : Void#
@@ -92,7 +92,7 @@
 -- Copy -----------------------------------------------------------------------
 -- | Copy a vector into a fresh buffer.
 copyVector8 
-        [r1 r2 : %]
+        [r1 r2 : Region]
         (vec1 : Ptr# r1 Obj)
         : Ptr# r2 Obj
  = do   
@@ -112,7 +112,7 @@
 
 
 copyPtr8
-        [r1 r2 : %]
+        [r1 r2 : Region]
         (offset : Nat#)
         (length : Nat#)
         (src : Ptr# r1 Word8#)
diff --git a/salt/primitive32/Int.dcs b/salt/primitive32/Int.dcs
--- a/salt/primitive32/Int.dcs
+++ b/salt/primitive32/Int.dcs
@@ -2,37 +2,37 @@
 -- | Int primitives for 32-bit machines.
 module Int
 exports
-        boxInt    :: [r : %]. Int#   -> Ptr# r Obj
-        unboxInt  :: [r : %]. Ptr# r Obj -> Int#
-        addInt    :: [r1 r2 r3 : %]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
-        subInt    :: [r1 r2 r3 : %]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
-        mulInt    :: [r1 r2 r3 : %]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
+        boxInt    :: [r : Region]. Int#   -> Ptr# r Obj
+        unboxInt  :: [r : Region]. Ptr# r Obj -> Int#
+        addInt    :: [r1 r2 r3 : Region]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
+        subInt    :: [r1 r2 r3 : Region]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
+        mulInt    :: [r1 r2 r3 : Region]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
 
 imports 
-        allocRawSmall :: [r : %]. Tag# -> Nat# -> Ptr# r Obj
+        allocRawSmall :: [r : Region]. Tag# -> Nat# -> Ptr# r Obj
 
 with letrec
 
 
-boxInt [r : %] (x : Int#) : Ptr# r Obj
+boxInt [r : Region] (x : Int#) : Ptr# r Obj
  = do   obj     = allocRawSmall [r] TAG0# 4#
         addr    = takePtr# [r] [Obj] obj
         write#  [Int#] addr 4# x
         obj
 
 
-unboxInt [r : %] (obj : Ptr# r Obj) : Int#
+unboxInt [r : Region] (obj : Ptr# r Obj) : Int#
  = do   addr    = takePtr# [r] [Obj] obj
         read#   [Int#] addr 4#
 
 
-addInt [r1 r2 r3 : %] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
+addInt [r1 r2 r3 : Region] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
  = boxInt [r3] (add# [Int#] (unboxInt [r1] x) (unboxInt [r2] y))
 
 
-subInt [r1 r2 r3 : %] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
+subInt [r1 r2 r3 : Region] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
  = boxInt [r3] (sub# [Int#] (unboxInt [r1] x) (unboxInt [r2] y))
 
 
-mulInt [r1 r2 r3 : %] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
+mulInt [r1 r2 r3 : Region] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
  = boxInt [r3] (mul# [Int#] (unboxInt [r1] x) (unboxInt [r2] y))
diff --git a/salt/primitive64/Int.dcs b/salt/primitive64/Int.dcs
--- a/salt/primitive64/Int.dcs
+++ b/salt/primitive64/Int.dcs
@@ -2,38 +2,38 @@
 -- | Int primitives for 64-bit machines.
 module Int
 exports
-        boxInt    :: [r : %]. Int#   -> Ptr# r Obj
-        unboxInt  :: [r : %]. Ptr# r Obj -> Int#
-        addInt    :: [r1 r2 r3 : %]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
-        subInt    :: [r1 r2 r3 : %]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
-        mulInt    :: [r1 r2 r3 : %]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
+        boxInt    :: [r : Region]. Int#   -> Ptr# r Obj
+        unboxInt  :: [r : Region]. Ptr# r Obj -> Int#
+        addInt    :: [r1 r2 r3 : Region]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
+        subInt    :: [r1 r2 r3 : Region]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
+        mulInt    :: [r1 r2 r3 : Region]. Ptr# r1 Obj -> Ptr# r2 Obj -> Ptr# r3 Obj
 
 imports
-        allocRawSmall :: [r : %]. Tag# -> Nat# -> Ptr# r Obj
+        allocRawSmall :: [r : Region]. Tag# -> Nat# -> Ptr# r Obj
 
 with letrec 
 
 
-boxInt [r : %] (x : Int#) : Ptr# r Obj
+boxInt [r : Region] (x : Int#) : Ptr# r Obj
  = do   obj     = allocRawSmall [r] TAG0# 8#
         addr    = takePtr# [r] [Obj] obj
         write#  [Int#] addr 4# x
         obj
 
 
-unboxInt [r : %] (obj : Ptr# r Obj) : Int#
+unboxInt [r : Region] (obj : Ptr# r Obj) : Int#
  = do   addr    = takePtr# [r] [Obj] obj
         read#   [Int#] addr 4#
 
 
-addInt [r1 r2 r3 : %] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
+addInt [r1 r2 r3 : Region] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
  = boxInt [r3] (add# [Int#] (unboxInt [r1] x) (unboxInt [r2] y))
 
 
-subInt [r1 r2 r3 : %] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
+subInt [r1 r2 r3 : Region] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
  = boxInt [r3] (sub# [Int#] (unboxInt [r1] x) (unboxInt [r2] y))
 
 
-mulInt [r1 r2 r3 : %] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
+mulInt [r1 r2 r3 : Region] (x : Ptr# r1 Obj) (y : Ptr# r2 Obj) : Ptr# r3 Obj
  = boxInt [r3] (mul# [Int#] (unboxInt [r1] x) (unboxInt [r2] y))
 
diff --git a/salt/runtime32/Object.dcs b/salt/runtime32/Object.dcs
--- a/salt/runtime32/Object.dcs
+++ b/salt/runtime32/Object.dcs
@@ -28,7 +28,7 @@
 --           0  1  0  1  a  0  0  1  -- SuspIndir
 --           -- size --  a  0  1  1  -- DataRawSmall
 -- 
---   * GC Forwarding / Broken-Heart pointers.
+--   Data GC Forwarding / Broken-Heart pointers.
 --     During garbage collection, after the GC copies an object to the
 --     "to-space" its header in the "from-space" is overwritten with a pointer
 --     to where the "to-space" version of the object is.
@@ -39,12 +39,12 @@
 --     For all other values of the format field, we ensure the lowest two bits
 --     are not 00.
 -- 
---   * Anchor flag
+--   Data Anchor flag
 --     If bit 3 in the format field is set then the GC is not permitted to move
 --     the object. This is useful when the object has been allocated by malloc
 --     and exists outside the DDC runtime's garbage collected heap.
 -- 
---   * Data{Boxed, Mixed, Raw, RawSmall}
+--   Data Data{Boxed, Mixed, Raw, RawSmall}
 --     There are four data object formats:
 --      DataBoxed:    A boxed object containing pointers to more heap objects.
 --      DataMixed:    Some heap pointers, and some raw data.
@@ -67,26 +67,26 @@
 --
 module Object 
 exports
-        getTag            :: [r : %]. Ptr# r Obj -> Tag#
+        getTag            :: [r : Region]. Ptr# r Obj -> Tag#
 
-        allocBoxed        :: [r : %]. Tag# -> Nat# -> Ptr# r Obj
-        getFieldOfBoxed   :: [r : %]. [a : *]. Ptr# r Obj -> Nat# -> a
-        setFieldOfBoxed   :: [r : %]. [a : *]. Ptr# r Obj -> Nat# -> a -> Void#
+        allocBoxed        :: [r : Region]. Tag# -> Nat# -> Ptr# r Obj
+        getFieldOfBoxed   :: [r : Region]. [a : Data]. Ptr# r Obj -> Nat# -> a
+        setFieldOfBoxed   :: [r : Region]. [a : Data]. Ptr# r Obj -> Nat# -> a -> Void#
 
-        allocMixed        :: [r : %]. Tag# -> Nat# -> Nat# -> Ptr# r Obj
-        fieldOfMixed      :: [r : %]. Ptr# r Obj -> Nat# -> Ptr# r Obj
-        payloadOfMixed    :: [r : %]. Ptr# r Obj -> Ptr# r Word8#
+        allocMixed        :: [r : Region]. Tag# -> Nat# -> Nat# -> Ptr# r Obj
+        fieldOfMixed      :: [r : Region]. Ptr# r Obj -> Nat# -> Ptr# r Obj
+        payloadOfMixed    :: [r : Region]. Ptr# r Obj -> Ptr# r Word8#
 
-        allocRaw          :: [r : %]. Tag# -> Nat# -> Ptr# r Obj
-        payloadOfRaw      :: [r : %]. Ptr# r Obj -> Ptr# r Word8#
+        allocRaw          :: [r : Region]. Tag# -> Nat# -> Ptr# r Obj
+        payloadOfRaw      :: [r : Region]. Ptr# r Obj -> Ptr# r Word8#
 
-        allocRawSmall     :: [r : %]. Tag# -> Nat# -> Ptr# r Obj
-        payloadOfRawSmall :: [r : %]. Ptr# r Obj -> Ptr# r Word8#
+        allocRawSmall     :: [r : Region]. Tag# -> Nat# -> Ptr# r Obj
+        payloadOfRawSmall :: [r : Region]. Ptr# r Obj -> Ptr# r Word8#
 
 with letrec
 
 -- | Get the constructor tag of an object.
-getTag [r : %] (obj : Ptr# r Obj) : Tag#
+getTag [r : Region] (obj : Ptr# r Obj) : Tag#
  = do   
         ptr             = castPtr# [r] [Word32#] [Obj] obj
         header          = peek# [r] [Word32#] ptr 0#
@@ -102,11 +102,11 @@
 --   {    uint32_t  tagFormat;    // Constructor tag and format field.
 --        uint32_t  arity;        // Arity of the data constructor.
 --                                //  (The number of pointers in the payload)
---        Obj*      payload[];    
+--        ObjData      payload[];    
 --   } DataBoxed;
 --    
 allocBoxed 
-        [r : %]
+        [r : Region]
         (tag : Tag#) (arity : Nat#) : Ptr# r Obj
  = do   
         -- multiply arity by 4 bytes-per-pointer to get size of payload.
@@ -118,7 +118,7 @@
          False# -> fail# [Ptr# r Obj]
 
 allocBoxed_ok
-        [r : %]
+        [r : Region]
         (tag : Tag#) (arity : Nat#) (bytesObj : Nat#) : Ptr# r Obj
  = do   
         addr            = alloc# bytesObj
@@ -136,7 +136,7 @@
 
 ---- | Get one of the pointers from a boxed data object.
 getFieldOfBoxed 
-        [r1 : %] [a : *] 
+        [r1 : Region] [a : Data] 
         (obj : Ptr# r1 Obj) (index : Nat#) 
         : a
  =      read# [a]  (takePtr# [r1] [Obj] obj)
@@ -145,7 +145,7 @@
 
 -- | Set one of the pointers from a boxed data object.
 setFieldOfBoxed 
-        [r1 : %] [a : *]
+        [r1 : Region] [a : Data]
         (obj : Ptr# r1 Obj) (index : Nat#) 
         (val : a) 
         : Void#
@@ -163,11 +163,11 @@
 --           uint32_t  padding;      // Padding to ensure payload is 8 byte aligned.
 --           uint32_t  size;         // Size of the whole object, in bytes.
 --           uint32_t  ptrCount;     // Number of pointers at the start of the payload.
---           Obj*      payload[];    // Contains ptrCount pointers, then raw data.
+--           ObjData      payload[];    // Contains ptrCount pointers, then raw data.
 --   } DataMixed;
 --
 allocMixed
-        [r : %]
+        [r : Region]
         (tag : Tag#) (arity : Nat#) (bytesRaw : Nat#) : Ptr# r Obj
  = do   
         bytesPtrs       = shl# [Nat#] arity 2#
@@ -177,7 +177,7 @@
          False# -> fail# [Ptr# r Obj]
 
 allocMixed_ok 
-        [r : %]
+        [r : Region]
         (tag : Tag#) (arity : Nat#) (bytesRaw : Nat#) (bytesObj : Nat#) : Ptr# r Obj
  = do
         addr            = alloc# bytesObj
@@ -198,14 +198,14 @@
 
 
 -- | Get one of the pointers from a mixed data object.
-fieldOfMixed [r : %] (obj : Ptr# r Obj) (index : Nat#) : Ptr# r Obj
+fieldOfMixed [r : Region] (obj : Ptr# r Obj) (index : Nat#) : Ptr# r Obj
  = do   
         offset          = add# [Nat#] 16# (shl# [Nat#] index 2#)
         plusPtr# [r] [Obj] obj offset
       
 
 -- | Get the address of the raw data payload from a mixed object.
-payloadOfMixed [r : %] (obj : Ptr# r Obj) : Ptr# r Word8#
+payloadOfMixed [r : Region] (obj : Ptr# r Obj) : Ptr# r Word8#
  =      plusPtr# [r] [Word8#] (castPtr# [r] [Word8#] [Obj] obj) 16#
 
 
@@ -221,7 +221,7 @@
 --   } DataRaw;
 --
 allocRaw
-        [r : %]
+        [r : Region]
         (tag : Tag#) (bytesPayload : Nat#) : Ptr# r Obj
  = do   
         bytesObj        = add# [Nat#] 8# bytesPayload
@@ -230,7 +230,7 @@
          False# -> fail# [Ptr# r Obj]
 
 allocRaw_ok 
-        [r : %] 
+        [r : Region] 
         (tag : Tag#) (bytesPayload : Nat#) (bytesObj : Nat#) : Ptr# r Obj
  = do
         addr            = alloc# bytesObj
@@ -247,7 +247,7 @@
 
 
 -- | Get the payload data from a raw object.
-payloadOfRaw [r : %] (obj : Ptr# r Obj) : Ptr# r Word8#
+payloadOfRaw [r : Region] (obj : Ptr# r Obj) : Ptr# r Word8#
  =      plusPtr# [r] [Word8#] (castPtr# [r] [Word8#] [Obj] obj) 8#
 
 
@@ -262,7 +262,7 @@
 --   } DataRawSmall;
 --
 allocRawSmall 
-        [r : %] 
+        [r : Region] 
         (tag : Tag#) (bytesPayload : Nat#) : Ptr# r Obj
  = do   
         bytesObj        = add# [Nat#] 4# bytesPayload
@@ -271,7 +271,7 @@
          False# -> fail# [Ptr# r Obj]
 
 allocRawSmall_ok
-        [r : %] 
+        [r : Region] 
         (tag : Tag#) (bytesPayload : Nat#) (bytesObj : Nat#) : Ptr# r Obj
  = do
         addr            = alloc# bytesObj
@@ -289,5 +289,5 @@
 
 
 -- | Get the payload data from a raw small object.
-payloadOfRawSmall [r : %] (obj : Ptr# r Obj) : Ptr# r Word8#
+payloadOfRawSmall [r : Region] (obj : Ptr# r Obj) : Ptr# r Word8#
  =      plusPtr# [r] [Word8#] (castPtr# [r] [Word8#] [Obj] obj) 4#
diff --git a/salt/runtime64/Object.dcs b/salt/runtime64/Object.dcs
--- a/salt/runtime64/Object.dcs
+++ b/salt/runtime64/Object.dcs
@@ -28,7 +28,7 @@
 --           0  1  0  1  a  0  0  1  -- SuspIndir
 --           -- size --  a  0  1  1  -- DataRawSmall
 -- 
---   * GC Forwarding / Broken-Heart pointers.
+--   Data GC Forwarding / Broken-Heart pointers.
 --     During garbage collection, after the GC copies an object to the
 --     "to-space" its header in the "from-space" is overwritten with a pointer
 --     to where the "to-space" version of the object is.
@@ -39,12 +39,12 @@
 --     For all other values of the format field, we ensure the lowest two bits
 --     are not 00.
 -- 
---   * Anchor flag
+--   Data Anchor flag
 --     If bit 3 in the format field is set then the GC is not permitted to move
 --     the object. This is useful when the object has been allocated by malloc
 --     and exists outside the DDC runtime's garbage collected heap.
 -- 
---   * Data{Boxed, Mixed, Raw, RawSmall}
+--   Data Data{Boxed, Mixed, Raw, RawSmall}
 --     There are four data object formats:
 --      DataBoxed:    A boxed object containing pointers to more heap objects.
 --      DataMixed:    Some heap pointers, and some raw data.
@@ -67,26 +67,26 @@
 --
 module Object 
 exports
-        getTag            :: [r : %]. Ptr# r Obj -> Tag#
+        getTag            :: [r : Region]. Ptr# r Obj -> Tag#
 
-        allocBoxed        :: [r : %]. Tag# -> Nat# -> Ptr# r Obj
-        getFieldOfBoxed   :: [r : %]. [a : *]. Ptr# r Obj -> Nat# -> a
-        setFieldOfBoxed   :: [r : %]. [a : *]. Ptr# r Obj -> Nat# -> a -> Void#
+        allocBoxed        :: [r : Region]. Tag# -> Nat# -> Ptr# r Obj
+        getFieldOfBoxed   :: [r : Region]. [a : Data]. Ptr# r Obj -> Nat# -> a
+        setFieldOfBoxed   :: [r : Region]. [a : Data]. Ptr# r Obj -> Nat# -> a -> Void#
 
-        allocMixed        :: [r : %]. Tag# -> Nat# -> Nat# -> Ptr# r Obj
-        fieldOfMixed      :: [r : %]. Ptr# r Obj -> Nat# -> Ptr# r Obj
-        payloadOfMixed    :: [r : %]. Ptr# r Obj -> Ptr# r Word8#
+        allocMixed        :: [r : Region]. Tag# -> Nat# -> Nat# -> Ptr# r Obj
+        fieldOfMixed      :: [r : Region]. Ptr# r Obj -> Nat# -> Ptr# r Obj
+        payloadOfMixed    :: [r : Region]. Ptr# r Obj -> Ptr# r Word8#
 
-        allocRaw          :: [r : %]. Tag# -> Nat# -> Ptr# r Obj
-        payloadOfRaw      :: [r : %]. Ptr# r Obj -> Ptr# r Word8#
+        allocRaw          :: [r : Region]. Tag# -> Nat# -> Ptr# r Obj
+        payloadOfRaw      :: [r : Region]. Ptr# r Obj -> Ptr# r Word8#
 
-        allocRawSmall     :: [r : %]. Tag# -> Nat# -> Ptr# r Obj
-        payloadOfRawSmall :: [r : %]. Ptr# r Obj -> Ptr# r Word8#
+        allocRawSmall     :: [r : Region]. Tag# -> Nat# -> Ptr# r Obj
+        payloadOfRawSmall :: [r : Region]. Ptr# r Obj -> Ptr# r Word8#
 
 with letrec
 
 -- | Get the constructor tag of an object.
-getTag [r : %] (obj : Ptr# r Obj) : Tag#
+getTag [r : Region] (obj : Ptr# r Obj) : Tag#
  = do   
         ptr             = castPtr# [r] [Word32#] [Obj] obj
         header          = peek# [r] [Word32#] ptr 0#
@@ -106,11 +106,11 @@
 --   {    uint32_t  tagFormat;    // Constructor tag and format field.
 --        uint32_t  arity;        // Arity of the data constructor.
 --                                //  (The number of pointers in the payload)
---        Obj*      payload[];    
+--        ObjData      payload[];    
 --   } DataBoxed;
 --    
 allocBoxed
-        [r : %]
+        [r : Region]
         (tag : Tag#) (arity : Nat#) : Ptr# r Obj
  = do   
         -- Multiple arity by 8 bytes-per-pointer to get size of payload.
@@ -124,7 +124,7 @@
          False# -> fail# [Ptr# r Obj]
 
 allocBoxed_ok
-        [r : %]
+        [r : Region]
         (tag : Tag#) (arity : Nat#) (bytesObj : Nat#) : Ptr# r Obj
  = do   
         addr            = alloc# bytesObj
@@ -143,7 +143,7 @@
 
 ---- | Get one of the pointers from a boxed data object.
 getFieldOfBoxed 
-        [r1 : %] [a : *]
+        [r1 : Region] [a : Data]
         (obj : Ptr# r1 Obj) (index : Nat#) 
         : a
  =      read# [a]  (takePtr# [r1] [Obj] obj)
@@ -153,7 +153,7 @@
 
 -- | Set one of the pointers from a boxed data object.
 setFieldOfBoxed 
-        [r1 : %] [a : *] 
+        [r1 : Region] [a : Data] 
         (obj : Ptr# r1 Obj) (index : Nat#)
         (val : a) 
         : Void#
@@ -174,11 +174,11 @@
 --   {       uint32_t  tagFormat;
 --           uint32_t  ptrCount;     // Number of pointers at the start of the payload.
 --           uint64_t  size;         // Size of the whole object, in bytes.
---           Obj*      payload[];    // Contains ptrCount pointers, then raw data.
+--           ObjData      payload[];    // Contains ptrCount pointers, then raw data.
 --   } DataMixed;
 --
 allocMixed 
-        [r : %]
+        [r : Region]
         (tag : Tag#) (arity : Nat#) (bytesRaw : Nat#) : Ptr# r Obj
  = do   
         bytesPtrs       = shl# [Nat#] arity 3#
@@ -192,7 +192,7 @@
          False# -> fail# [Ptr# r Obj]
 
 allocMixed_ok
-        [r : %]
+        [r : Region]
         (tag : Tag#) (arity : Nat#) (bytesObj : Nat#) : Ptr# r Obj
  = do
         addr            = alloc# bytesObj
@@ -212,7 +212,7 @@
 
 
 -- | Get one of the pointers from a mixed data object.
-fieldOfMixed [r : %] (obj : Ptr# r Obj) (index : Nat#) : Ptr# r Obj
+fieldOfMixed [r : Region] (obj : Ptr# r Obj) (index : Nat#) : Ptr# r Obj
  = do   
         offset          = add# [Nat#] 16# 
                          (shl# [Nat#] index (size2# [Addr#]))
@@ -221,7 +221,7 @@
       
 
 -- | Get the address of the raw data payload from a mixed object.
-payloadOfMixed [r : %] (obj : Ptr# r Obj) : Ptr# r Word8#
+payloadOfMixed [r : Region] (obj : Ptr# r Obj) : Ptr# r Word8#
  =      plusPtr# [r] [Word8#] (castPtr# [r] [Word8#] [Obj] obj) 16#
 
 
@@ -239,7 +239,7 @@
 --   } DataRaw;
 --
 allocRaw
-        [r : %] 
+        [r : Region] 
         (tag : Tag#) (bytesPayload : Nat#) : Ptr# r Obj
  = do   
         bytesObj        = add# [Nat#] (size# [Word32#])
@@ -251,7 +251,7 @@
          False# -> fail# [Ptr# r Obj]
 
 allocRaw_ok
-        [r : %]
+        [r : Region]
         (tag : Tag#) (bytesObj : Nat#) : Ptr# r Obj
  = do
         addr            = alloc# bytesObj
@@ -268,7 +268,7 @@
 
 
 -- | Get the payload data from a raw object.
-payloadOfRaw [r : %] (obj : Ptr# r Obj) : Ptr# r Word8#
+payloadOfRaw [r : Region] (obj : Ptr# r Obj) : Ptr# r Word8#
  =      plusPtr# [r] [Word8#] (castPtr# [r] [Word8#] [Obj] obj) 8#
 
 
@@ -285,7 +285,7 @@
 --   } DataRawSmall;
 --
 allocRawSmall
-        [r : %]
+        [r : Region]
         (tag : Tag#) (bytesPayload : Nat#) : Ptr# r Obj
  = do   
         bytesObj        = add# [Nat#] 4# bytesPayload
@@ -294,7 +294,7 @@
          False#  -> fail# [Ptr# r Obj]
 
 allocRawSmall_ok
-        [r : %]
+        [r : Region]
         (tag : Tag#) (bytesPayload : Nat#) (bytesObj : Nat#) : Ptr# r Obj
  = do   
         addr            = alloc# bytesObj
@@ -312,6 +312,6 @@
 
 
 -- | Get the payload data from a raw small object.
-payloadOfRawSmall [r : %] (obj : Ptr# r Obj) : Ptr# r Word8#
+payloadOfRawSmall [r : Region] (obj : Ptr# r Obj) : Ptr# r Word8#
  =      plusPtr# [r] [Word8#] (castPtr# [r] [Word8#] [Obj] obj) 4#