diff --git a/byg/src/DependencyRunner.hs b/byg/src/DependencyRunner.hs
index 2e48a6f..832b08d 100644
--- a/byg/src/DependencyRunner.hs
+++ b/byg/src/DependencyRunner.hs
@@ -86,7 +86,7 @@ tupApp ta tb = App (App (typeRep @(,)) ta) tb
 listApp :: TypeRep a -> TypeRep [a]
 listApp ta = App (typeRep @[]) ta
 
-runAction :: Action -> Value -> DepRunM Value
+runAction :: Action a b -> Value -> DepRunM Value
 runAction action input = case action of
   Function f ->
     pure $ toValue $ evalFunction f $ fromValue input
diff --git a/byg/src/Types/Dependency.hs b/byg/src/Types/Dependency.hs
index 878107f..263a585 100644
--- a/byg/src/Types/Dependency.hs
+++ b/byg/src/Types/Dependency.hs
@@ -19,19 +19,19 @@ import Text.Printf (printf)
 import Data.Text (Text)
 import qualified Data.Text as T
 
-data Action where
-  Function :: IsFunction f a b => f -> Action
-  InlineFunction :: Show b => TypeRep a -> TypeRep b -> F a b -> Action
-  FunctionIO :: IsFunctionIO f a b => f -> Action
-  Inject :: Value -> Action
-  FilterComp :: Show a => TypeRep a -> Action
-  UntupleFst :: (Show a, Show b) => TypeRep a -> TypeRep b -> Action
-  UntupleSnd :: (Show a, Show b) => TypeRep a -> TypeRep b -> Action
-  UnzipFst :: (Show a, Show b) => TypeRep a -> TypeRep b -> Action
-  UnzipSnd :: (Show a, Show b) => TypeRep a -> TypeRep b -> Action
-  MapComp :: (Typeable a, Show a, Typeable b, Show b) => TypeRep a -> TypeRep b -> [Dependency] -> Token a -> Token b -> Action
+data Action a b where
+  Function :: IsFunction f a b => f -> Action a b
+  InlineFunction :: Show b => TypeRep a -> TypeRep b -> F a b -> Action a b
+  FunctionIO :: IsFunctionIO f a b => f -> Action a b
+  Inject :: Value -> Action () a
+  FilterComp :: Show a => TypeRep a -> Action ([a], [Bool]) [a]
+  UntupleFst :: (Show a, Show b) => TypeRep a -> TypeRep b -> Action (a, b) a
+  UntupleSnd :: (Show a, Show b) => TypeRep a -> TypeRep b -> Action (a, b) b
+  UnzipFst :: (Show a, Show b) => TypeRep a -> TypeRep b -> Action [(a, b)] [a]
+  UnzipSnd :: (Show a, Show b) => TypeRep a -> TypeRep b -> Action [(a, b)] [b]
+  MapComp :: (Typeable a, Show a, Typeable b, Show b) => TypeRep a -> TypeRep b -> [Dependency] -> Token a -> Token b -> Action [a] [b]
 
-deriving instance Show Action
+deriving instance Show (Action a b)
 
 newtype F a b = F (a -> b)
 
@@ -39,10 +39,10 @@ instance Show (F a b) where
   show = const "<function>"
 
 data Dependency where
-  Dependency :: (Typeable a, Show a) => TypeRep a -> Token a -> Action -> TypeRep b -> Token b -> Dependency
+  Dependency :: (Typeable a, Show a) => TypeRep a -> Token a -> Action a b -> TypeRep b -> Token b -> Dependency
 deriving instance Show Dependency
 
-makeDependency :: (Typeable a, Show a, Typeable b, Show b) => Token a -> Action -> Token b -> Dependency
+makeDependency :: (Typeable a, Show a, Typeable b, Show b) => Token a -> Action a b -> Token b -> Dependency
 makeDependency a action b = Dependency typeRep a action typeRep b
 
 unListType :: Typeable a => TypeRep [a] -> TypeRep a
@@ -51,7 +51,7 @@ unListType _ = typeRep
 unTupleType :: (Typeable a, Typeable b) => TypeRep (a, b) -> (TypeRep a, TypeRep b)
 unTupleType _ = (typeRep, typeRep)
 
-actionTouchesFilesystem :: Action -> Bool
+actionTouchesFilesystem :: Action a b -> Bool
 actionTouchesFilesystem = \case
   Function _ -> False
   InlineFunction _ _ _ -> False
@@ -105,6 +105,7 @@ formatDependencyTrees = T.concat . (formatDependencyTrees' "")
           NoToken ->
             [ "--" ]
 
+        formatAction :: Text -> Action a b -> [Text]
         formatAction indentation = \case
           MapComp _ _ subDeps innerInput innerOutput ->
             concat [ [ "MapComp(" ]