diff --git a/src/Data/Map/Implicit.hs b/src/Data/Map/Implicit.hs
index ac0d459..ab2906e 100644
--- a/src/Data/Map/Implicit.hs
+++ b/src/Data/Map/Implicit.hs
@@ -1,41 +1,27 @@
 {-# LANGUAGE Safe #-}
-{-# LANGUAGE TypeFamilies #-} -- for KeyType
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE StandaloneDeriving #-} -- specify instance contexts
 {-# LANGUAGE FlexibleContexts #-} -- use non type-variable argument in instance head
 {-# LANGUAGE UndecidableInstances #-} -- use type family in instance head
-{-# LANGUAGE InstanceSigs #-}
 -- | A Map that derives the keys for the mapping from the items.
 
 module Data.Map.Implicit (ImplicitMap(), get, ImplicitKeyOf(..), empty) where
 import Data.Kind (Type, Constraint)
 import Data.Map (Map)
-import Text.Show (Show (show))
-import Data.String (String)
-import Control.Category ((.), Category (id))
 import Data.Map qualified as Map
-import Text.Read (Read (readPrec), ReadPrec)
-import Data.List qualified as List
-import Control.Arrow (Arrow ((&&&)))
-import Data.Functor ((<$>))
+import Text.Show (Show)
+import Text.Read (Read)
 import Data.Ord (Ord)
 
 type ImplicitMap :: Type -> Type
 type role ImplicitMap nominal
 newtype ImplicitMap v = ImplicitMap { get :: Map (KeyType v) v }
 
-type ImplicitMapElems :: Type -> Type
-type role ImplicitMapElems representational
-newtype ImplicitMapElems v = ImplicitMapElems [v]
-  deriving stock (Show, Read)
-
-instance (Show v) => Show (ImplicitMap v) where
-  show :: ImplicitMap v -> String
-  show = show . ImplicitMapElems . Map.elems . get
-
-instance (Read v, ImplicitKeyOf v, Ord (KeyType v)) => Read (ImplicitMap v) where
-  readPrec :: ReadPrec (ImplicitMap v)
-  readPrec = ImplicitMap . Map.fromList . List.map (keyOf &&& id) . (\(ImplicitMapElems es) -> es) <$> readPrec
+deriving stock instance (Show (KeyType v), Show v) => Show (ImplicitMap v)
+deriving stock instance (Read (KeyType v), Ord (KeyType v), Read v) => Read (ImplicitMap v)
 
 type ImplicitKeyOf :: Type -> Constraint
+
 class ImplicitKeyOf v where
   type KeyType v :: Type
   keyOf :: v -> KeyType v
diff --git a/src/Language/Scalie/Ast/Module.hs b/src/Language/Scalie/Ast/Module.hs
index 8d127aa..f90f9d1 100644
--- a/src/Language/Scalie/Ast/Module.hs
+++ b/src/Language/Scalie/Ast/Module.hs
@@ -8,32 +8,20 @@ module Language.Scalie.Ast.Module (Module(..)) where
 import Data.Kind (Type)
 import Language.Scalie.Ast.Definition (Definition)
 import Data.Map.Implicit (ImplicitMap)
-import Text.Show (Show)
+import Text.Show ( Show )
 import Text.Read (Read)
+import Data.Text (Text)
+import Language.Scalie.Ast.Expression (Expression)
+import Language.Scalie.Domain.Type qualified as Scalie.Domain
+import Data.Ord (Ord)
 
 -- | A module groups multiple related definitions.
---
--- >>> import Data.Functor.Identity (Identity(..))
--- >>> import Data.Map.Implicit qualified as ImplicitMap
--- >>> Module (Identity ImplicitMap.empty)
--- Module {definitions = Identity ImplicitMapElems []}
---
--- >>> import Data.Maybe (Maybe(..))
--- >>> Module Nothing
--- Module {definitions = Nothing}
---
--- >>> import Text.Read (readMaybe)
--- >>> readMaybe "Module { definitions = Just (ImplicitMapElems []) }" :: Maybe (Module Maybe)
--- Just (Module {definitions = Just ImplicitMapElems []})
---
--- >>> readMaybe "Module { definitions = Just (ImplicitMapElems [Definition { signature = Nothing, name = Just \"x\", body = Nothing } ]) }" :: Maybe (Module Maybe)
--- Just (Module {definitions = Just ImplicitMapElems [Definition {signature = Nothing, name = Just "x", body = Nothing}]})
 
 type Module :: (Type -> Type) -> Type
 type role Module nominal
 data Module f = Module
-  { definitions :: f (ImplicitMap (Definition f))
+  { definitions :: ImplicitMap (Definition f)
   }
 
-deriving stock instance (Show (f (ImplicitMap (Definition f)))) => Show (Module f)
-deriving stock instance (Read (f (ImplicitMap (Definition f)))) => Read (Module f)
+deriving stock instance (Show (f Text), Show (f Expression), Show (f Scalie.Domain.Type)) => Show (Module f)
+deriving stock instance (Read (f Text), Ord (f Text), Read (f Expression), Read (f Scalie.Domain.Type)) => Read (Module f)