diff --git a/ersatz-viz.cabal b/ersatz-viz.cabal
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--- /dev/null
+++ b/ersatz-viz.cabal
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+cabal-version: 3.8
+
+name: ersatz-viz
+version: 0
+synopsis: draw circuit (DAG) for Ersatz.Bit
+description:
+  draw circuit (DAG) for Ersatz.Bit
+  .
+  example usage: see test/Works.hs
+license: GPL-3.0-only
+author: Johannes Waldmann
+homepage: https://git.imn.htwk-leipzig.de/waldmann/ersatz-viz
+  
+library
+  hs-source-dirs: src
+  exposed-modules: Ersatz.Bit.Display
+  other-modules: Ersatz.Internal.StableName
+  build-depends: base < 4.24 , text, process-extras, unordered-containers,
+    mtl, lens, ersatz
+  default-language: GHC2021
+  
+test-suite works
+  hs-source-dirs: test
+  main-is: Works.hs
+  type: exitcode-stdio-1.0
+  build-depends: base, text, ersatz, ersatz-viz
+  default-language: GHC2021
diff --git a/src/Ersatz/Bit/Display.hs b/src/Ersatz/Bit/Display.hs
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--- /dev/null
+++ b/src/Ersatz/Bit/Display.hs
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+{-# language OverloadedStrings #-}
+{-# language LambdaCase #-}
+
+module Ersatz.Bit.Display where
+
+import Ersatz.Bit (Bit(..))
+import Ersatz.Internal.StableName
+import Ersatz.Problem (runSAT')
+import Control.Monad (void, forM, forM_)
+import Control.Monad.RWS
+import Data.HashMap.Lazy (HashMap)
+import qualified Data.HashMap.Lazy as HashMap
+import System.IO.Unsafe
+import Control.Lens
+import Data.Foldable (toList)
+import Data.Text (Text)
+import qualified Data.Text as T
+import System.Process.Text
+import System.Mem.StableName (StableName, makeStableName)
+import Unsafe.Coerce (unsafeCoerce)
+
+
+display m = dot $ fst $ runSAT' m
+
+dot b = void $ readProcessWithExitCode "dot" [ "-Tx11" ] $ toDot b
+
+toDot :: Bit -> Text
+toDot b = snd
+  $ ( \ m -> evalRWS (do
+       tell "digraph Bit {"
+       tell "graph [ordering=\"out\"]"
+       tell "node [style=\"plane\"]"
+       m
+       tell "}"
+    ) () s0 )
+  $ walk b
+
+subs :: Bit -> [Bit]
+subs b = case b of
+  Not (And xs) -> toList xs
+  And xs -> toList xs
+  Xor a b -> [a,b]
+  Mux a b c -> [a,b,c]
+  Not a -> [a]
+  Var {} -> []
+  Run {} -> []
+
+name :: Bit -> Text
+name b = case b of
+  Not (And {}) -> "nand"
+  And {} -> "and"
+  Xor {} -> "xor"
+  Mux {} -> "mux"
+  Not {} -> "not"
+  Var l -> T.pack $ show l
+  Run {} -> "run"
+
+data State = State
+  { _stableMap :: !(HashMap (StableName ()) Int)
+  , _next :: !Int
+  }
+
+s0 :: State
+s0 = State { _stableMap = HashMap.empty , _next = 0 }
+
+stableMap :: Lens' State (HashMap (StableName ()) Int)
+stableMap f (s@State {_stableMap = sm})
+  = fmap (\ sm' -> s { _stableMap = sm'} ) (f sm)
+
+next :: Lens' State Int
+next f (s@State { _next = n })
+  = fmap (\ n' -> s { _next = n' } ) (f n)
+  
+fresh :: RWST () Text State Identity Int
+fresh = do this <- use next ; next += 1 ; return this
+
+walk :: Bit -> RWST () Text State Identity Int
+walk b = do
+  let sn = unsafePerformIO (makeStableName' b)
+  use (stableMap.at sn) >>= \ case
+    Just n -> return n
+    Nothing -> do
+      this <- fresh
+      stableMap.at sn ?= this
+      cs <- forM (subs b) walk
+      tell $ T.pack (show this) <> "[label=\"" <> name b <> "\"];"
+      forM_ cs $ \ c -> do
+        tell $ T.pack (show this) <> "->" <> T.pack (show c) <> ";"
+      return this
diff --git a/src/Ersatz/Internal/StableName.hs b/src/Ersatz/Internal/StableName.hs
new file mode 100644
--- /dev/null
+++ b/src/Ersatz/Internal/StableName.hs
@@ -0,0 +1,23 @@
+{-# OPTIONS_HADDOCK not-home #-}
+--------------------------------------------------------------------
+-- |
+-- Copyright :  © Edward Kmett 2010-2014, Johan Kiviniemi 2013
+-- License   :  BSD3
+-- Maintainer:  Edward Kmett <ekmett@gmail.com>
+-- Stability :  experimental
+-- Portability: non-portable
+--
+--------------------------------------------------------------------
+module Ersatz.Internal.StableName
+  ( StableName
+  , makeStableName'
+  ) where
+
+import System.Mem.StableName (StableName, makeStableName)
+import Unsafe.Coerce (unsafeCoerce)
+
+makeStableName' :: a -> IO (StableName ())
+makeStableName' a = a `seq` fmap coerceStableName (makeStableName a)
+  where
+    coerceStableName :: StableName a -> StableName ()
+    coerceStableName = unsafeCoerce
diff --git a/test/Works.hs b/test/Works.hs
new file mode 100644
--- /dev/null
+++ b/test/Works.hs
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+import Prelude hiding (and,or,all,any,not,(&&),(||))
+import Ersatz
+import qualified Ersatz.Counting as C
+
+import qualified Ersatz.Bit.Display as D
+import Control.Monad (replicateM)
+import qualified Data.Text.IO as T
+
+-- | print dot expression to stdout
+main :: IO ()
+main = T.putStrLn $ D.toDot $ fst $ runSAT' mkBit
+
+-- | render and display.
+-- will open a window and block ghci,
+-- hit 'q' in window to close window and unblock ghci.
+run :: IO ()
+run = D.display mkBit
+
+mkBit :: MonadSAT s m => m Bit
+mkBit = do
+  xs <- replicateM 4 (exists @Bit)
+  return $ C.exactly 1 xs