diff --git a/lib/src/translator/MergeDict.hs b/lib/src/translator/MergeDict.hs
new file mode 100644
index 000000000..1707db8d0
--- /dev/null
+++ b/lib/src/translator/MergeDict.hs
@@ -0,0 +1,87 @@
+{-
+Merge two concrete syntaxes that have lin rules of the form
+
+  lin f = t1 | ... | tn ; -- comment
+
+one per line. The concrete syntaxes are marked "old" and "new", where "old" is more trusted. Merging
+
+  lin f = t1 | ... | tm ; -- comment1
+  lin f = u1 | ... | un ; -- comment2
+
+results in
+
+  lin f = t1 | ... | tm | {- SEP -} u1' | ... | un' ; -- comment 1 -- comment2
+
+where u1'... are without duplicates. The comment SEP is given as an argument.
+
+If either grammar is missing the rule for f, then only the other grammar is used. 
+
+Comments can be added at the merging phase.
+
+Other lines than 'lin' rules are taken from "old". The rules in the resulting grammar are sorted alphabetically.
+
+Usage:
+
+  mergeDict "DictionaryChi.gf" "../chinese/hsk/csv/hsku.gf" (Just "HSK") "tmp/DictionaryChi.gf"
+-}
+
+
+
+import Data.List
+
+
+mergeDict :: FilePath -> FilePath -> Maybe String -> FilePath -> IO ()
+mergeDict old new comm file = do
+  olds1 <- readFile old >>= return . lines
+  news1 <- readFile new >>= return . lines
+  let (preamble,olds2) = break ((== ["lin"]) . take 1 . words) olds1
+  let olds = [mkRule (w:ws) | w:ws <- map words olds2, w == "lin"]
+  let news = [mkRule (w:ws) | w:ws <- map words news1, w == "lin"]
+  let lins = sort $ [(f,0) | f <- olds] ++ [(f,1) | f <- news]
+  let linss = groupBy (\x y -> (fun (fst x)) == (fun (fst y))) lins
+  let lins2 = map (mergeRule comm) linss
+  writeFile file $ unlines preamble
+  appendFile file $ unlines $ map prRule lins2
+  appendFile file "}"
+
+data Rule = R {fun :: String, lins :: [[String]], comment :: [String]} -- fun, variants, comment
+  deriving (Eq,Ord)
+
+mkRule :: [String] -> Rule
+mkRule ws = case ws of
+  "lin":f:"=":ww -> rule f (getLin ww)
+  _ -> error $ "not a valid rule: " ++ unwords ws
+ where
+   rule f (l,c) = R f l c
+   getLin ws = case break isComment ws of
+     (ls,cc) -> (getVariants (init ls), cc)
+   getVariants ws = case break (=="|") ws of
+      (e,vs) | isEmpty e -> getVariants vs
+      (v,_:vs) -> v : getVariants vs
+      (v,_)    -> [v]
+   isEmpty v = elem v [["variants{}"],["variants","{}"]]
+   isComment = (=="--") . take 2
+
+mergeRule :: Maybe String -> [(Rule,Int)] -> Rule
+mergeRule mco rs = case rs of
+  [(r,_)] -> r
+  [(old,_),(new,_)] -> R (fun old) (mergeLin (lins old) (lins new)) (comment old ++ comment new)
+ where
+   mergeLin old new = olds ++ case filter (flip notElem old) new of
+     l:ls -> case mco of 
+       Just co -> (("{-"++co++"-}"):l):ls
+       _ -> l:ls
+     _ -> []
+    where
+     olds = case old of
+       [[]] -> [["variants","{}"]]
+       _ -> old
+
+prRule :: Rule -> String
+prRule ru = unwords $ "lin" : fun ru : "=" : variants ru ++ [";"] ++ comment ru
+
+variants :: Rule -> [String]
+variants ru = case lins ru of
+  [[]] -> ["variants","{}"] 
+  ls -> intersperse "|" (map unwords ls)
+