diff --git a/ChangeLog.md b/ChangeLog.md
new file mode 100644
--- /dev/null
+++ b/ChangeLog.md
@@ -0,0 +1,20 @@
+# Change log for total-map
+
+## 0.1.0
+
+*   Derived `Show` instance.
+*   `infixl 9 !`
+*   `DetectableZero` instance.
+*   Added a change log.
+
+## 0.0.8
+
+*   `Semiring` and `StarSemiring` instances.
+
+## 0.0.7
+
+*   `Semigroup` instance.
+
+## 0.0.6
+
+*   `codomain`
diff --git a/README.md b/README.md
new file mode 100644
--- /dev/null
+++ b/README.md
@@ -0,0 +1,20 @@
+The usual finite map type (`Map` from `Data.Map`) is not an applicative functor, as it doesn't have a pure.
+Consequently, it's also not a monad.
+On the other hand, we can decompose `Map` into two parts: a *total* map, and `Maybe`, i.e.,
+
+    type Map k v = TMap k (Maybe v)
+
+The type `TMap` of total maps does have `Applicative` and `Monad` instances, and hence this hypothetically rebuilt `Map` would as well.
+
+The idea for `TMap` is introduced in the paper [*Denotational design with type class morphisms*](http://conal.net/papers/type-class-morphisms/).
+The meaning `Map k v` is given by its semantic function
+
+    (!) :: Map k v -> (k -> v)
+
+The type class morphism (TCM) principle then exactly dictates the meanings of several class instances for `TMap`, including `Functor`, `Applicative`, `Monad`, and `Monoid`.
+For instance, `(!)` must be a monoid (homo)morphism, i.e.,
+
+    (!) mempty == mempty
+    (!) (s `mappend` t) == (!) s `mappend` (!) t
+
+The current implementation of `TMap` is via `Data.Map`.
diff --git a/src/Data/TotalMap.hs b/src/Data/TotalMap.hs
--- a/src/Data/TotalMap.hs
+++ b/src/Data/TotalMap.hs
@@ -13,7 +13,11 @@
 -- a default value. Has Applicative and Monad instances (unlike "Data.Map").
 ----------------------------------------------------------------------
 
-module Data.TotalMap (TMap,fromPartial,(!),tabulate,trim,intersectionPartialWith,codomain) where
+module Data.TotalMap
+  ( TMap,fromPartial,(!),tabulate,trim
+  , intersectionPartialWith,codomain
+  -- , tmapRepr
+  ) where
 
 import Data.Monoid (Monoid(..),(<>))
 import Control.Applicative (Applicative(..),liftA2,(<$>))
@@ -31,7 +35,7 @@
 -- import Control.Comonad  -- TODO
 
 -- | Total map
-data TMap k v = TMap v (Map k v)
+data TMap k v = TMap v (Map k v) deriving Show
 
 -- The representation is a default value and a finite map for the rest.
 
@@ -39,6 +43,7 @@
 fromPartial :: a -> Map k a -> TMap k a
 fromPartial = TMap
 
+infixl 9 !
 -- | Sample a total map. Semantic function.
 (!) :: Ord k => TMap k v -> k -> v
 TMap dflt m ! k = fromMaybe dflt (M.lookup k m)
@@ -162,6 +167,9 @@
   star = fmap star
   plus = fmap plus
 
+instance (Ord k, DetectableZero v) => DetectableZero (TMap k v) where
+  isZero (TMap d m) = isZero d && M.null m -- or: isZero d && all isZero (elems m)
+
 {--------------------------------------------------------------------
     Comonad
 --------------------------------------------------------------------}
@@ -177,3 +185,7 @@
 idMap = M.fromAscList . map (\ k -> (k,k)) . S.toAscList
 
 -- or ... map (join (,)) ...
+
+-- -- | Reveal representation. For use while experimenting.
+-- tmapRepr :: TMap k v -> (v, Map k v)
+-- tmapRepr (TMap d m) = (d,m)
diff --git a/total-map.cabal b/total-map.cabal
--- a/total-map.cabal
+++ b/total-map.cabal
@@ -1,6 +1,6 @@
 Name:                total-map
-Version:             0.0.8
-Cabal-Version:       >= 1.6
+Version:             0.1.0
+Cabal-Version:       >= 1.10
 Synopsis:            Finitely represented /total/ maps
 Category:            Data
 Description:
@@ -14,6 +14,9 @@
 Stability:           experimental
 build-type:          Simple
 Homepage:            http://github.com/conal/total-map/
+Extra-Source-Files:
+    README.md
+    ChangeLog.md
 Source-Repository head
     type:         git
     location:     git://github.com/conal/total-map.git
@@ -25,3 +28,4 @@
                        -- , comonad
   Exposed-Modules:     
                        Data.TotalMap
+  default-language: Haskell2010