diff --git a/src/GEval/Clippings.hs b/src/GEval/Clippings.hs
index eb7c86a..fcdb5b2 100644
--- a/src/GEval/Clippings.hs
+++ b/src/GEval/Clippings.hs
@@ -5,14 +5,10 @@ module GEval.Clippings
 
 import Data.Attoparsec.Text
 import Data.Text
-import Control.Applicative
-import Control.Exception
 import Data.Char (isSpace)
 import Data.List (unfoldr)
 import Data.Maybe (catMaybes)
 
-import Debug.Trace
-
 import GEval.Common
 import GEval.PrecisionRecall (maxMatch)
 
@@ -49,7 +45,7 @@ lineClippingsParser = sepByWhitespaces clippingParser
 clippingParser :: Parser Clipping
 clippingParser = do
   pageNo <- PageNumber <$> decimal
-  char '/'
+  _ <- char '/'
   rectangle <- rectangleParser
   return $ Clipping pageNo rectangle
 
@@ -59,9 +55,9 @@ lineClippingSpecsParser = sepByWhitespaces clippingSpecParser
 clippingSpecParser :: Parser ClippingSpec
 clippingSpecParser = do
   pageNo <- PageNumber <$> decimal
-  char '/'
+  _ <- char '/'
   rectangle <- rectangleParser
-  char '/'
+  _ <- char '/'
   margin <- decimal
   return $ ClippingSpec pageNo (smallerRectangle margin rectangle) (extendedRectangle margin rectangle)
 
@@ -73,7 +69,7 @@ labeledClippingParser =
 clippingWithLabelParser :: Parser LabeledClipping
 clippingWithLabelParser = do
   label <- takeWhile1 (\c -> not (isSpace c) && c /= ':')
-  string ":"
+  _ <- string ":"
   clipping <- clippingParser
   return $ LabeledClipping (Just label) clipping
 
@@ -90,8 +86,7 @@ smallerRectangle margin (Rectangle (Point x0 y0) (Point x1 y1)) =
   Rectangle (Point (x0 + margin) (y0 + margin))
             (Point (x1 `nonNegativeDiff` margin) (y1 `nonNegativeDiff` margin))
 
-
-
+nonNegativeDiff :: (Ord p, Num p) => p -> p -> p
 nonNegativeDiff x y
   | x < y = 0
   | otherwise = x - y
@@ -99,11 +94,11 @@ nonNegativeDiff x y
 rectangleParser :: Parser Rectangle
 rectangleParser = do
   x0 <- decimal
-  char ','
+  _ <- char ','
   y0 <- decimal
-  char ','
+  _ <- char ','
   x1 <- decimal
-  char ','
+  _ <- char ','
   y1 <- decimal
   if x1 < x0 || y1 < y0
   then fail "wrong coordinates"
@@ -128,7 +123,7 @@ coveredBy clippingsA clippingsB = sum
     step ([], _) = Nothing
     step (firstA:restA, b) = Just (result, (newA ++ restA, newB))
        where (result, newA, newB) = step' firstA b
-    step' rectA [] = (Nothing, [], [])
+    step' _ [] = (Nothing, [], [])
     step' a (firstB:restB) = case partitionClippings a firstB of
       Just (commonRect, leftoversA, leftoversB) -> (Just commonRect, leftoversA, leftoversB ++ restB)
       Nothing -> let
@@ -160,8 +155,9 @@ getLeftovers (Rectangle (Point x0 y0) (Point x1 y1))
                          Rectangle (Point x0 (y1 + 1)) (Point x1 y1'),
                          Rectangle (Point x0' y0') (Point (x0 - 1) y1'),
                          Rectangle (Point (x1 + 1) y0') (Point x1' y1')]
-  where validRectangle (Rectangle (Point x0 y0) (Point x1 y1)) = x0 <= x1 && y0 <= y1
+  where validRectangle (Rectangle (Point x0'' y0'') (Point x1'' y1'')) = x0'' <= x1'' && y0'' <= y1''
 
+clippEUMatchStep :: ([ClippingSpec], [Clipping]) -> (Int, Int, Int)
 clippEUMatchStep (clippingSpecs, clippings) = (maxMatch matchClippingToSpec clippingSpecs clippings,
                                                Prelude.length clippingSpecs,
                                                Prelude.length clippings)
diff --git a/src/GEval/PrecisionRecall.hs b/src/GEval/PrecisionRecall.hs
index a4e889e..245de95 100644
--- a/src/GEval/PrecisionRecall.hs
+++ b/src/GEval/PrecisionRecall.hs
@@ -10,13 +10,10 @@ module GEval.PrecisionRecall(calculateMAPForOneResult,
                              countFragFolder, fMeasureOnSeparatedCounts, f1MeasureOnSeparatedCounts)
        where
 
-import Debug.Trace
-
 import GEval.Common
 import GEval.Probability
 
 import Data.Graph.Inductive
-import Data.Graph.Inductive.Query.MaxFlow
 
 import Data.List (find, foldl', nub)
 
@@ -28,10 +25,10 @@ import qualified Data.HashMap.Strict as M
 calculateMAPForOneResult :: (Eq a) => [a] -> [a] -> Double
 calculateMAPForOneResult expected got = precisionSum / fromIntegral (length expected)
   where (_::Int, _, precisionSum) = calculateMAPForOneResultCore expected (nub got)
-        calculateMAPForOneResultCore expected got = foldl' (oneMAPStep expected) (0, 0, 0.0) got
-        oneMAPStep expected (gotCount, allCount, precisionSum) gotItem
-          | gotItem `elem` expected = (newGotCount, newAllCount, precisionSum + (newGotCount /. newAllCount))
-          | otherwise = (gotCount, newAllCount, precisionSum)
+        calculateMAPForOneResultCore expected' got' = foldl' (oneMAPStep expected') (0, 0, 0.0) got'
+        oneMAPStep expected' (gotCount, allCount, precisionSum') gotItem
+          | gotItem `elem` expected' = (newGotCount, newAllCount, precisionSum' + (newGotCount /. newAllCount))
+          | otherwise = (gotCount, newAllCount, precisionSum')
          where newGotCount = gotCount + 1
                newAllCount = allCount + 1
 
@@ -53,7 +50,7 @@ fMeasure beta matchingFun expected got = weightedHarmonicMean beta p r
 weightedHarmonicMean :: Double -> Double -> Double -> Double
 weightedHarmonicMean beta x y =
   (1 + betaSquared) * x * y `safeDoubleDiv` (betaSquared * x + y)
-  where betaSquared = beta ^ 2
+  where betaSquared = beta ^ (2 :: Int)
 
 f2MeasureOnCounts :: ConvertibleToDouble n => (n, Int, Int) -> Double
 f2MeasureOnCounts = fMeasureOnCounts 2.0
@@ -127,9 +124,9 @@ maxMatchOnOrdered laterThan expected got =
 -- counting maximum match with maximum bipartite matching
 -- (we build an auxiliary graph and do a max-flow on this)
 maxMatch :: (a -> b -> Bool) -> [a] -> [b] -> Int
-maxMatch matchFun expected got = mf
+maxMatch matchFun expected got = mfVal
    where (b, e, g) = buildGraph matchFun expected got
-         mf = maxFlow g (fst b) (fst e)
+         mfVal = maxFlow g (fst b) (fst e)
 
 buildGraph :: (a -> b -> Bool) -> [a] -> [b] -> (LNode Int, LNode Int, Gr Int Int)
 buildGraph matchFun expected got = (b, e, g)
@@ -138,7 +135,7 @@ buildGraph matchFun expected got = (b, e, g)
            run empty $
              do b <- insMapNodeM 0
                 e <- insMapNodeM 1
-                mapM insMapNodeM [2..1+(length expected)+(length got)]
+                _ <- mapM insMapNodeM [2..1+(length expected)+(length got)]
                 insMapEdgesM $ map (\n -> (0, n, 1)) expectedIxs
                 insMapEdgesM $ map (\m -> (m, 1, 1)) gotIxs
                 insMapEdgesM $ map (\(n,m) -> (n, m, 1))
@@ -172,7 +169,7 @@ getProbabilisticCounts (expected, got) = (results, (map getProbabilityAsDouble g
                                               length expected)
   where gotMass = sum $ map (\(i, j) -> (matchScore (expected !! (i - 1)) (got !! (j - 1))) * (getProbabilityAsDouble (got !! (j - 1))))  matching
         results = map findResult [1..(length got)]
-        findResult j = case find (\(i, j') -> j' == j) $ matching of
+        findResult j = case find (\(_, j') -> j' == j) $ matching of
           Just (i, _) -> matchScore (expected !! (i - 1)) (got !! (j - 1))
           Nothing -> 0.0
         (matching, _) = weightedMaxMatching matchScore expected got