diff --git a/cabal.project b/cabal.project
index bc3e346..d1e1495 100644
--- a/cabal.project
+++ b/cabal.project
@@ -1,4 +1,4 @@
 packages:
   initial-encoding
   leibniz-proof
-  parser-closed
+  tagless-final
diff --git a/parser-closed/parser-closed.cabal b/parser-closed/parser-closed.cabal
deleted file mode 100644
index 03f0c8a..0000000
--- a/parser-closed/parser-closed.cabal
+++ /dev/null
@@ -1,13 +0,0 @@
-  cabal-version:      3.4
-  name:               parser-closed
-  version:            0.1.0.0
-
-executable parser-closed
-  main-is:          Main.hs
-  build-depends:    base ^>=4.14.3.0,
-                    eq,
-                    megaparsec,
-                    parser-combinators,
-                    text
-  hs-source-dirs:   app
-  default-language: Haskell2010
diff --git a/tagless-final/app/Main.hs b/tagless-final/app/Main.hs
new file mode 100644
index 0000000..6d96a09
--- /dev/null
+++ b/tagless-final/app/Main.hs
@@ -0,0 +1,21 @@
+module Main where
+
+import qualified Text.Megaparsec as M
+
+import Closed.Parser
+import Data.Text.IO (hGetContents)
+import System.Environment (getArgs)
+import System.IO (IOMode(ReadMode), openFile)
+
+-- ========================================
+-- Main
+-- ========================================
+
+main :: IO ()
+main = do
+  [fileName] <- getArgs
+  handle <- openFile fileName ReadMode
+  contents <- hGetContents handle
+  case M.parse expr fileName contents of
+    Left e -> print $ M.errorBundlePretty e
+    Right a -> print (fromDyn a :: Maybe (Eval Integer))
diff --git a/parser-closed/app/Main.hs b/tagless-final/src/Closed/Parser.hs
similarity index 81%
rename from parser-closed/app/Main.hs
rename to tagless-final/src/Closed/Parser.hs
index 806658d..481a1e6 100644
--- a/parser-closed/app/Main.hs
+++ b/tagless-final/src/Closed/Parser.hs
@@ -3,11 +3,21 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE ViewPatterns #-}
 
-module Main where
+module Closed.Parser
+( Dynamic(..)
+, Eval(..)
+, Parser
+, SQ(..)
+, Symantics(..)
+, TQ(..)
+, Typeable(..)
+, expr
+, fromDyn
+, toDyn
+) where
 
 import qualified Control.Monad.Combinators.Expr as E
 import qualified Data.Eq.Type as EQ
@@ -16,17 +26,10 @@ import qualified Text.Megaparsec.Char as MC
 import qualified Text.Megaparsec.Char.Lexer as ML
 
 import Control.Applicative ((<|>))
-import Data.Char (isDigit)
 import Data.Eq.Type ((:=))
-import Data.Foldable (foldl')
 import Data.Functor (($>), void)
-import Data.Proxy (Proxy(..))
 import Data.Text (Text, unpack)
-import Data.Text.IO (hGetContents)
 import Data.Void (Void)
-import Numeric (readDec)
-import System.Environment (getArgs)
-import System.IO (IOMode(ReadMode), openFile)
 
 -- ========================================
 -- Symantics
@@ -50,15 +53,15 @@ instance Symantics SQ where
   eAnd (SQ lhs) (SQ rhs) = SQ (eAnd lhs rhs)
   eOr  (SQ lhs) (SQ rhs) = SQ (eOr  lhs rhs)
 
-newtype Expr a = Expr {runExpr :: a} deriving Show
+newtype Eval a = Eval {runEval :: a} deriving Show
 
-instance Symantics Expr where
-  eInt  = Expr
-  eBool = Expr
-  eAdd (Expr lhs) (Expr rhs) = Expr (lhs + rhs)
-  eSub (Expr lhs) (Expr rhs) = Expr (lhs - rhs)
-  eAnd (Expr lhs) (Expr rhs) = Expr (lhs && rhs)
-  eOr  (Expr lhs) (Expr rhs) = Expr (lhs || rhs)
+instance Symantics Eval where
+  eInt  = Eval
+  eBool = Eval
+  eAdd (Eval lhs) (Eval rhs) = Eval (lhs + rhs)
+  eSub (Eval lhs) (Eval rhs) = Eval (lhs - rhs)
+  eAnd (Eval lhs) (Eval rhs) = Eval (lhs && rhs)
+  eOr  (Eval lhs) (Eval rhs) = Eval (lhs || rhs)
 
 -- ========================================
 -- Typeable
@@ -144,13 +147,13 @@ boolean = lexeme_ do
 {-# INLINE boolean #-}
 
 integer :: Parser Integer
-integer = lexeme_ do
-  i <- M.some $ M.satisfy isDigit
-  case readDec i of
-    [(value, "")] -> pure value
-    _ -> fail "integer"
+integer = lexeme_ ML.decimal
 {-# INLINE integer #-}
 
+-- ========================================
+-- Deserialization
+-- ========================================
+
 mkBinary
   :: forall repr a
    . Symantics repr
@@ -184,16 +187,3 @@ expr = expr' >>= \case
       case mkBinary bin lhs' rhs' of
         Nothing -> Left (offset, "Invalid operands for `" <> unpack name <> "`")
         Just a -> pure a
-
--- ========================================
--- Main
--- ========================================
-
-main :: IO ()
-main = do
-  [fileName] <- getArgs
-  handle <- openFile fileName ReadMode
-  contents <- hGetContents handle
-  case M.parse expr fileName contents of
-    Left e -> print $ M.errorBundlePretty e
-    Right a -> print (fromDyn a :: Maybe (Expr Integer))
diff --git a/tagless-final/tagless-final.cabal b/tagless-final/tagless-final.cabal
new file mode 100644
index 0000000..6346fdd
--- /dev/null
+++ b/tagless-final/tagless-final.cabal
@@ -0,0 +1,22 @@
+  cabal-version:      3.4
+  name:               tagless-final
+  version:            0.1.0.0
+
+executable tagless-final
+  main-is:          Main.hs
+  build-depends:    base ^>=4.14.3.0,
+                    megaparsec,
+                    tagless-final,
+                    text
+  hs-source-dirs:   app
+  default-language: Haskell2010
+
+library
+  build-depends:      base ^>=4.14.3.0,
+                      eq,
+                      megaparsec,
+                      parser-combinators,
+                      text
+  hs-source-dirs:     src
+  default-language:   Haskell2010
+  exposed-modules:    Closed.Parser