diff --git a/CHANGELOG.md b/CHANGELOG.md
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+++ b/CHANGELOG.md
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+# Revision history for tangle
+
+## 0 -- 2020-02-09
+
+* First version. Released on an unsuspecting world.
diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
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+Copyright (c) 2020, Fumiaki Kinoshita
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Fumiaki Kinoshita nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/Setup.hs b/Setup.hs
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+++ b/Setup.hs
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+import Distribution.Simple
+main = defaultMain
diff --git a/src/Control/Monad/Tangle.hs b/src/Control/Monad/Tangle.hs
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+++ b/src/Control/Monad/Tangle.hs
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+{-# LANGUAGE RankNTypes, LambdaCase, GeneralizedNewtypeDeriving, DeriveFunctor, BangPatterns #-}
+module Control.Monad.Tangle (TangleT(..), hitch, evalTangleT) where
+
+import Control.Applicative
+import Control.Monad.Trans.Class
+import Control.Monad.IO.Class
+import Data.Functor.Identity
+
+newtype TangleT t m a = TangleT
+  { runTangleT :: t (TangleT t m) -> t Maybe -> m (t Maybe, a) }
+  deriving Functor
+
+instance Monad m => Applicative (TangleT t m) where
+  pure a = TangleT $ \_ mem -> pure (mem, a)
+  TangleT m <*> TangleT n = TangleT $ \ts mem -> m ts mem
+    >>= \(mem', f) -> (\(mem'', a) -> (mem'', f a)) <$> n ts mem'
+instance Monad m => Monad (TangleT t m) where
+  TangleT m >>= k = TangleT $ \ts mem -> m ts mem >>= \(mem', a) -> runTangleT (k a) ts mem'
+
+instance (Monad m, Semigroup a) => Semigroup (TangleT t m a) where
+  (<>) = liftA2 (<>)
+
+instance (Monad m, Monoid a) => Monoid (TangleT t m a) where
+    mempty = pure mempty
+
+instance MonadTrans (TangleT t) where
+  lift m = TangleT $ \_ mem -> fmap ((,) mem) m 
+
+instance MonadIO m => MonadIO (TangleT t m) where
+  liftIO m = TangleT $ \_ mem -> fmap ((,) mem) (liftIO m)
+
+hitch :: Monad m
+  => (forall h f. Functor f => (h a -> f (h a)) -> t h -> f (t h))
+  -> TangleT t m a
+hitch l = TangleT $ \ts mem -> getConst $ flip l mem $ \case
+  Just a -> Const $ pure (mem, a)
+  Nothing -> Const
+    $ fmap (\(mem', a) -> let !(Identity mem'') = l (const $ pure $ Just a) mem' in (mem'', a))
+    $ runTangleT (getConst $ l Const ts) ts mem
+{-# INLINE hitch #-}
+
+evalTangleT :: Functor m => TangleT t m a -> t (TangleT t m) -> t Maybe -> m a
+evalTangleT m t s = snd <$> runTangleT m t s
+{-# INLINE evalTangleT #-}
diff --git a/tangle.cabal b/tangle.cabal
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+++ b/tangle.cabal
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+cabal-version:       2.4
+-- Initial package description 'tangle.cabal' generated by 'cabal init'.
+-- For further documentation, see http://haskell.org/cabal/users-guide/
+
+name:                tangle
+version:             0
+synopsis:            HKD record builder
+description:         See README.md for details
+bug-reports:         https://github.com/fumieval/tangle/issues
+license:             BSD-3-Clause
+license-file:        LICENSE
+author:              Fumiaki Kinoshita
+maintainer:          fumiexcel@gmail.com
+copyright: Copyright(c) 2020 Fumiaki Kinoshita
+category: Monad
+extra-source-files:  CHANGELOG.md
+tested-with: GHC == 8.8.1, ghc == 8.6.5
+
+source-repository head
+  type: git
+  location: https://github.com/fumieval/tangle.git
+
+library
+  exposed-modules:     Control.Monad.Tangle
+  -- other-modules:
+  -- other-extensions:
+  build-depends:       base >= 4.12 && <5, transformers
+  hs-source-dirs:      src
+  default-language:    Haskell2010
+  ghc-options: -Wall