diff --git a/COPYING b/COPYING
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+++ b/COPYING
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+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
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+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<http://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.
diff --git a/Data/Interval.hs b/Data/Interval.hs
new file mode 100644
--- /dev/null
+++ b/Data/Interval.hs
@@ -0,0 +1,441 @@
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TupleSections #-}
+module Data.Interval where
+
+import           Control.DeepSeq (NFData(..))
+import           Data.Bool
+import           Data.Data (Data(..))
+import           Data.Eq (Eq(..))
+import           Data.Foldable (concat)
+import           Data.Function (($), flip)
+import           Data.Functor (Functor(..))
+import qualified Data.Functor as Functor
+import           Data.Maybe (Maybe(..))
+import           Data.Ord (Ord(..), Ordering(..))
+import           Data.Tuple
+import           Data.Typeable (Typeable)
+import           Prelude (Bounded(..), seq)
+import           Text.Show (Show(..))
+
+-- * Type 'Limit'
+
+data Limit x
+ =   Limit
+ { adherence :: Adherence
+ , limit     :: x }
+ deriving (Eq, Data, Show, Typeable)
+
+instance Functor Limit where
+	fmap f (Limit a x) = Limit a (f x)
+instance NFData x => NFData (Limit x) where
+	rnf (Limit _a l) = rnf l
+
+data Adherence = Out | In
+ deriving (Eq, Data, Show, Typeable)
+
+-- | Return given 'Limit' with its 'adherence' set to the opposite one.
+flip_limit :: Limit x -> Limit x
+flip_limit (Limit a x) = Limit (case a of { In -> Out; Out -> In }) x
+
+-- ** Comparing 'Limit's
+
+-- | Compare two 'low' 'Limit's.
+newtype LL x = LL { unLL :: x }
+ deriving (Eq)
+instance Ord x => Ord (LL (Limit x)) where
+	compare (LL x) (LL y) =
+		case compare (limit x) (limit y) of
+		 EQ ->
+			case (adherence x, adherence y) of
+			 (Out, In ) -> GT
+			 (In , Out) -> LT
+			 _          -> EQ
+		 o -> o
+
+-- | Compare two 'high' 'Limit's.
+newtype HH x = HH { unHH :: x }
+ deriving (Eq)
+instance Ord x => Ord (HH (Limit x)) where
+	compare (HH x) (HH y) =
+		case compare (limit x) (limit y) of
+		 EQ ->
+			case (adherence x, adherence y) of
+			 (Out, In ) -> LT
+			 (In , Out) -> GT
+			 _          -> EQ
+		 o -> o
+
+-- * Type 'Interval'
+
+newtype  Ord x
+ => Interval x
+ =  Interval (Limit x, Limit x)
+ deriving (Eq, Show, Data, Typeable)
+instance (NFData x, Ord x) => NFData (Interval x) where
+	rnf (Interval (x, y)) = rnf x `seq` rnf y
+
+low :: Ord x => Interval x -> Limit x
+low (Interval t)  = fst t
+
+high :: Ord x => Interval x -> Limit x
+high (Interval t) = snd t
+
+-- | Return 'Interval' with given 'low' then 'high' 'Limit's,
+--   if they form a valid 'Interval'.
+interval :: Ord x => Limit x -> Limit x -> Maybe (Interval x)
+interval x y =
+	case compare_without_adherence x y of
+	 LT -> Just $ Interval (x, y)
+	 EQ ->
+		case (adherence x, adherence y) of
+		 (In, In) -> Just $ Interval (x, y)
+		 _        -> Nothing
+	 GT -> Nothing
+
+-- | Like 'Functor.fmap', but may return 'Nothing', if mapped 'Interval' is not valid.
+fmap :: (Ord x, Ord y) => (x -> y) -> Interval x -> Maybe (Interval y)
+fmap f (Interval (il, ih)) = interval (Functor.fmap f il) (Functor.fmap f ih)
+
+-- | Like 'Functor.fmap', but only safe if given map preserves 'Ordering'.
+fmap_unsafe :: (Ord x, Ord y) => (x -> y) -> Interval x -> Interval y
+fmap_unsafe f (Interval (il, ih)) = Interval (Functor.fmap f il, Functor.fmap f ih)
+
+{-
+-- | Like 'Functor.fmap', but on 'Limit's,
+--   and may return 'Nothing', if mapped 'Interval' is not valid.
+fmap_limits :: (Ord x, Ord y) => (Limit x -> Limit y) -> Interval x -> Maybe (Interval y)
+fmap_limits f (Interval (il, ih)) = interval (f il) (f ih)
+
+-- | Like 'Functor.fmap', but on 'Limit's
+--   and only safe if given map preserves 'Ordering'.
+fmap_limits_unsafe :: (Ord x, Ord y) => (Limit x -> Limit y) -> Interval x -> Interval y
+fmap_limits_unsafe f (Interval (il, ih)) = Interval (f il, f ih)
+-}
+
+-- | Lexicographical order, handling 'Adherence' correctly.
+instance Ord x => Ord (Interval x) where
+	compare (Interval (il, ih)) (Interval (jl, jh)) =
+		case   compare (LL il) (LL jl) of
+		 EQ -> compare (HH ih) (HH jh)
+		 o  -> o
+
+-- | Return 'limit's of given 'Interval' as a tuple.
+limits :: Ord x => Interval x -> (Limit x, Limit x)
+limits (Interval t) = t
+
+-- | Return an 'Interval' spanning over a single 'limit'.
+point :: Ord x => x -> Interval x
+point x = Interval (Limit In x, Limit In x)
+
+-- | Return given 'Interval' with 'flip_limit' applied to its 'limit's.
+flip_limits :: Ord x => Interval x -> Interval x
+flip_limits (Interval (l, h)) = Interval (flip_limit l, flip_limit h)
+
+-- | Return 'Ordering' comparing given 'Interval's according to their 'limit's.
+compare_without_adherence :: Ord x => Limit x -> Limit x -> Ordering
+compare_without_adherence (Limit _ x) (Limit _ y) = compare x y
+
+-- | Return:
+--
+-- * 'LT': if given value is lower  than all values in given 'Interval'.
+-- * 'EQ': if given value is into the given 'Interval'.
+-- * 'GT': if given value is higher than all values in given 'Interval'.
+locate :: Ord x => x -> Interval x -> Ordering
+locate x (Interval (l, h)) =
+	case compare x (limit l) of
+	 LT -> LT
+	 EQ | adherence l == In -> EQ
+	 EQ -> LT
+	 GT ->
+		case compare x (limit h) of
+		 LT -> EQ
+		 EQ | adherence h == In -> EQ
+		 EQ -> GT
+		 GT -> GT
+
+-- | Return 'True' iif. given value is into the given 'Interval'.
+within :: Ord x => x -> Interval x -> Bool
+within x i = locate x i == EQ
+
+-- | Return 'True' iif. every value of the first 'Interval' is into the second 'Interval'.
+into :: Ord x => Interval x -> Interval x -> Bool
+into i j =
+	case position i j of
+	 (Prefix  , LT) -> True
+	 (Suffixed, GT) -> True
+	 (Include , GT) -> True
+	 (Equal   , _)  -> True
+	 _              -> False
+
+-- | Return 'True' iif. every value of the second 'Interval' is into the first 'Interval'.
+onto :: Ord x => Interval x -> Interval x -> Bool
+onto = flip into
+
+infix 5 <=..<=
+(<=..<=) :: Ord x => x -> x -> Maybe (Interval x)
+(<=..<=) x y =
+	case compare x y of
+	 LT -> Just $ Interval (Limit In x, Limit In y)
+	 EQ -> Just $ Interval (Limit In x, Limit In y)
+	 GT -> Nothing
+
+infix 5 <..<=
+(<..<=) :: Ord x => x -> x -> Maybe (Interval x)
+(<..<=) x y =
+	case compare x y of
+	 LT -> Just $ Interval (Limit Out x, Limit In y)
+	 EQ -> Nothing
+	 GT -> Nothing
+
+infix 5 <=..<
+(<=..<) :: Ord x => x -> x -> Maybe (Interval x)
+(<=..<) x y =
+	case compare x y of
+	 LT -> Just $ Interval (Limit In x, Limit Out y)
+	 EQ -> Nothing
+	 GT -> Nothing
+
+infix 5 <..<
+(<..<) :: Ord x => x -> x -> Maybe (Interval x)
+(<..<) x y =
+	case compare x y of
+	 LT -> Just $ Interval (Limit Out x, Limit Out y)
+	 EQ -> Nothing
+	 GT -> Nothing
+
+-- * Type 'Position'
+
+data Position
+ = Away     -- ^ @-_|@ ('LT') or @|_-@ ('GT')
+ | Adjacent -- ^ @-|@  ('LT') or @|-@  ('GT')
+ | Overlap  -- ^ @-+|@ ('LT') or @|+-@ ('GT')
+ | Prefix   -- ^ @+|@  ('LT') or @+-@  ('GT')
+ | Suffixed -- ^ @-+@  ('LT') or @|+@  ('GT')
+ | Include  -- ^ @-+-@ ('LT') or @|+|@ ('GT')
+ | Equal    -- ^ @+@ ('EQ')
+ deriving (Eq, Show)
+
+position :: Ord x => Interval x -> Interval x -> (Position, Ordering)
+position (Interval (il, ih)) (Interval (jl, jh)) =
+	case compare (LL il) (LL jl) of
+	 LT -> (, LT) $
+		case compare_without_adherence ih jl of
+		 LT -> Away -- PATTERN: -_|
+		 EQ ->
+			case (adherence ih, adherence jl) of
+			 (In , In)  -> Overlap  -- PATTERN: -+|
+			 (Out, Out) -> Away     -- PATTERN: -_|
+			 _          -> Adjacent -- PATTERN: -|
+		 GT ->
+			case compare (HH ih) (HH jh) of
+			 LT -> Overlap  -- PATTERN: -+|
+			 EQ -> Suffixed -- PATTERN: -+
+			 GT -> Include  -- PATTERN: -+-
+	 EQ ->
+		case compare (HH ih) (HH jh) of
+		 LT -> (Prefix, LT) -- PATTERN: +|
+		 EQ -> (Equal , EQ) -- PATTERN: +
+		 GT -> (Prefix, GT) -- PATTERN: +-
+	 GT -> (, GT) $
+		case compare_without_adherence il jh of
+		 LT ->
+			case compare (HH ih) (HH jh) of
+			 LT -> Include  -- PATTERN: |+|
+			 EQ -> Suffixed -- PATTERN: |+
+			 GT -> Overlap  -- PATTERN: |+-
+		 EQ ->
+			case (adherence il, adherence jh) of
+			 (In , In)  -> Overlap  -- PATTERN: |+-
+			 (Out, Out) -> Away     -- PATTERN: |_-
+			 _          -> Adjacent -- PATTERN: |-
+		 GT -> Away -- PATTERN: |_-
+
+infix 4 ..<<..
+-- | Return 'True' iif. 'Position' of given 'Interval's is ('Away', 'LT').
+(..<<..) :: Ord x => Interval x -> Interval x -> Bool
+(..<<..) i j = case position i j of
+	 (Away, LT) -> True
+	 _          -> False
+
+infix 4 ..>>..
+-- | Return 'True' iif. 'Position' of given 'Interval's is ('Away', 'GT').
+(..>>..) :: Ord x => Interval x -> Interval x -> Bool
+(..>>..) i j = case position i j of
+	 (Away, GT) -> True
+	 _          -> False
+
+infix 4 ..<..
+-- | Return 'True' iif. 'Position' of given 'Interval's is ('Away', 'LT') or ('Adjacent', 'LT').
+(..<..) :: Ord x => Interval x -> Interval x -> Bool
+(..<..) i j = case position i j of
+	 (Away    , LT) -> True
+	 (Adjacent, LT) -> True
+	 _              -> False
+infix 4 ..>..
+-- | Return 'True' iif. 'Position' of given 'Interval's is ('Away', 'GT') or ('Adjacent', 'GT').
+(..>..) :: Ord x => Interval x -> Interval x -> Bool
+(..>..) i j = case position i j of
+	 (Away    , GT) -> True
+	 (Adjacent, GT) -> True
+	 _              -> False
+
+infix 4 ..<=..
+-- | Return 'True' iif. 'Position' of given 'Interval's is ('Away', 'LT'), ('Adjacent', 'LT'), ('Overlap', 'LT'), ('Prefix', 'LT'), ('Suffixed', 'LT'), ('Include', 'GT'), or ('Equal', _).
+(..<=..) :: Ord x => Interval x -> Interval x -> Bool
+(..<=..) i j = case position i j of
+	 (Away    , LT) -> True
+	 (Adjacent, LT) -> True
+	 (Overlap , LT) -> True
+	 (Prefix  , LT) -> True
+	 (Suffixed, LT) -> True
+	 (Include , GT) -> True
+	 (Equal   , _ ) -> True
+	 _              -> False
+
+infix 4 ..>=..
+-- | Return 'True' iif. 'Position' of given 'Interval's is ('Away', 'GT'), ('Adjacent', 'GT'), ('Overlap', 'GT'), ('Prefix', 'GT'), ('Suffixed', 'GT'), ('Include', 'LT'), or ('Equal', _).
+(..>=..) :: Ord x => Interval x -> Interval x -> Bool
+(..>=..) i j = case position i j of
+	 (Away    , GT) -> True
+	 (Adjacent, GT) -> True
+	 (Overlap , GT) -> True
+	 (Prefix  , GT) -> True
+	 (Suffixed, GT) -> True
+	 (Include , LT) -> True
+	 (Equal   , _ ) -> True
+	 _              -> False
+
+-- * Merge
+
+union :: Ord x => Interval x -> Interval x -> Maybe (Interval x)
+union i j =
+	case position i j of
+	 (Away, _) -> -- PATTERN: -_| or |_-
+		Nothing
+	 (Adjacent, o) ->
+		case o of
+		 LT -> Just $ Interval (low i, high j) -- PATTERN: -|
+		 EQ -> Nothing
+		 GT -> Just $ Interval (low j, high i) -- PATTERN: |-
+	 (Overlap, o) ->
+		case o of
+		 LT -> Just $ Interval (low i, high j) -- PATTERN: -+|
+		 EQ -> Nothing
+		 GT -> Just $ Interval (low j, high i) -- PATTERN: |+-
+	 (Prefix, o) ->
+		case o of
+		 LT -> Just j -- PATTERN: +|
+		 EQ -> Nothing
+		 GT -> Just i -- PATTERN: +-
+	 (Suffixed, o) ->
+		case o of
+		 LT -> Just i -- PATTERN: -+
+		 EQ -> Nothing
+		 GT -> Just j -- PATTERN: |+
+	 (Include, o) ->
+		case o of
+		 LT -> Just i -- PATTERN: -+-
+		 EQ -> Nothing
+		 GT -> Just j -- PATTERN: |+|
+	 (Equal, _) ->  -- PATTERN: +
+		Just i
+
+intersection :: Ord x => Interval x -> Interval x -> Maybe (Interval x)
+intersection i j =
+	case position i j of
+	 (Away, _) -> -- PATTERN: -_| or |_-
+		Nothing
+	 (Adjacent, _) -> -- PATTERN: -| or |-
+		Nothing
+	 (Overlap, o) ->
+		case o of
+		 LT -> Just $ Interval (low j, high i) -- PATTERN: -+|
+		 EQ -> Nothing
+		 GT -> Just $ Interval (low i, high j) -- PATTERN: |+-
+	 (Prefix, o) ->
+		case o of
+		 LT -> Just i -- PATTERN: +|
+		 EQ -> Nothing
+		 GT -> Just j -- PATTERN: +-
+	 (Suffixed, o) ->
+		case o of
+		 LT -> Just j -- PATTERN: -+
+		 EQ -> Nothing
+		 GT -> Just i -- PATTERN: |+
+	 (Include, o) ->
+		case o of
+		 LT -> Just j -- PATTERN: -+-
+		 EQ -> Nothing
+		 GT -> Just i -- PATTERN: |+|
+	 (Equal, _) ->  -- PATTERN: +
+		Just i
+
+span :: Ord x => Interval x -> Interval x -> Interval x
+span i j =
+	Interval
+	 ( unLL (min (LL $ low  i) (LL $ low  j))
+	 , unHH (max (HH $ high i) (HH $ high j))
+	 )
+
+-- * Type 'Unlimitable'
+
+data Unlimitable x
+ = Unlimited_low
+ | Limited { limited :: x }
+ | Unlimited_high
+ deriving (Eq, Ord, Show)
+instance Functor Unlimitable where
+	fmap _f Unlimited_low  = Unlimited_low
+	fmap _f Unlimited_high = Unlimited_high
+	fmap f (Limited x)    = Limited (f x)
+instance Bounded (Unlimitable x) where
+	minBound = Unlimited_low
+	maxBound = Unlimited_high
+instance Bounded (Limit (Unlimitable x)) where
+	minBound = Limit In Unlimited_low
+	maxBound = Limit In Unlimited_high
+
+unlimited :: Ord x => Interval (Unlimitable x)
+unlimited = Interval ( Limit In Unlimited_low
+                     , Limit In Unlimited_high )
+
+unlimit :: Ord x => Interval x -> Interval (Unlimitable x)
+unlimit = fmap_unsafe Limited
+
+(<..) :: Ord x => x -> Interval (Unlimitable x)
+(<..) x = Interval (Limit Out (Limited x), Limit In Unlimited_high)
+
+(<=..) :: Ord x => x -> Interval (Unlimitable x)
+(<=..) x = Interval (Limit In (Limited x), Limit In Unlimited_high)
+
+(..<) :: Ord x => x -> Interval (Unlimitable x)
+(..<) x = Interval (Limit In Unlimited_low, Limit Out (Limited x))
+
+(..<=) :: Ord x => x -> Interval (Unlimitable x)
+(..<=) x = Interval (Limit In Unlimited_low, Limit In (Limited x))
+
+-- * Type 'Pretty'
+
+newtype Pretty x = Pretty x
+ deriving (Eq, Ord)
+instance (Ord x, Show x) => Show (Pretty (Interval x)) where
+	show (Pretty i) =
+		concat
+		 [ case adherence (low i) of
+			 In  -> "["
+			 Out -> "]"
+		 , show (limit $ low i)
+		 , ".."
+		 , show (limit $ high i)
+		 , case adherence (high i) of
+			 In  -> "]"
+			 Out -> "["
+		 ]
+instance (Ord x, Show x) => Show (Pretty (Unlimitable x)) where
+	show (Pretty x) =
+		case x of
+		 Unlimited_low  -> "-oo"
+		 Limited l      -> show l
+		 Unlimited_high -> "+oo"
diff --git a/Data/Interval/Sieve.hs b/Data/Interval/Sieve.hs
new file mode 100644
--- /dev/null
+++ b/Data/Interval/Sieve.hs
@@ -0,0 +1,254 @@
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TupleSections #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+module Data.Interval.Sieve where
+
+import           Control.Applicative (Applicative(..))
+import           Control.Exception (assert)
+import           Data.Bool
+import           Data.Eq (Eq(..))
+import           Data.FingerTree (FingerTree, ViewL(..), ViewR(..), (><), (<|), (|>))
+import qualified Data.FingerTree as FT
+import           Data.Foldable (Foldable)
+import qualified Data.Foldable as Foldable
+import           Data.Function (($), (.))
+import           Data.Functor ((<$>))
+import qualified Data.List
+import           Data.Maybe (Maybe(..), fromMaybe)
+import           Data.Monoid (Monoid(..))
+import           Data.Ord (Ord(..), Ordering(..))
+import           Prelude (Bounded(..), undefined)
+import           Text.Show (Show(..))
+
+import qualified Data.Interval as Interval
+import           Data.Interval ( Interval(..)
+                               , low, high
+                               , (..<..), (..<<..)
+                               , Position(..), position
+                               , flip_limit
+                               , Pretty(..) )
+
+-- * Type 'Sieve'
+
+-- | '..<<..'-ordered union of 'Interval's.
+--
+-- __Ressources:__
+--
+--  * Ralf Hinze and Ross Paterson,
+--    \"Finger trees: a simple general-purpose data structure\",
+--    /Journal of Functional Programming/ 16:2 (2006) pp 197-217.
+--    <http://staff.city.ac.uk/~ross/papers/FingerTree.html>
+--  * <https://hackage.haskell.org/package/fingertree/docs/Data-IntervalMap-FingerTree.html>
+newtype Sieve x =
+	Sieve { unSieve :: FingerTree (Measure x) (Interval x) }
+
+instance (Ord x, Show x) => Show (Pretty (Sieve x)) where
+	show (Pretty s) | Data.Interval.Sieve.null s = "empty"
+	show (Pretty s) = Data.List.intercalate " u " $ Data.List.map (show . Pretty) $ intervals s
+
+-- | Like 'Data.Functor.fmap' but working on 'Interval's.
+fmap_interval
+ :: (Ord x, Ord y)
+ => (Interval x -> Interval y) -> Sieve x -> Sieve y
+fmap_interval f (Sieve ft) = Sieve (FT.fmap' f ft)
+
+-- | Like 'Data.Functor.fmap' but working on 'Interval's,
+--   and safe only if 'Measure' is preserved.
+fmap_interval_unsafe
+ :: Ord x
+ => (Interval x -> Interval x)
+ -> Sieve x -> Sieve x
+fmap_interval_unsafe f (Sieve ft) = Sieve (FT.unsafeFmap f ft)
+
+-- | Like 'Data.Traversable.traverse' but working on 'Interval's.
+traverse_interval
+ :: (Ord x, Ord y, Applicative f)
+ => (Interval x -> f (Interval y))
+ -> Sieve x -> f (Sieve y)
+traverse_interval f (Sieve ft) = Sieve <$> FT.traverse' f ft
+
+-- | Like 'Data.Traversable.traverse' but working on 'Interval's,
+--   and safe only if 'Measure' is preserved.
+traverse_interval_unsafe
+ :: (Ord x, Applicative f)
+ => (Interval x -> f (Interval x))
+ -> Sieve x -> f (Sieve x)
+traverse_interval_unsafe f (Sieve ft) = Sieve <$> FT.unsafeTraverse f ft
+
+-- | 'FT.Measure' of each leaf or node of the 'Sieve' 'FingerTree'.
+data Measure x
+ = Measure_Empty -- ^ Measure of 'FT.empty' 'Fingertree'.
+ | Measure
+   { max_high_of_max_low :: Interval x
+	-- ^ An __'Interval' with the max 'high' 'Limit'__
+	--   __amongst those having the max 'low' 'Limit'__
+	--   (which is the 'max' 'Interval'
+	--   because of lexicographical ordering).
+  {- NOTE: not useful in the particular case of '..<..'-ordered 'Interval's
+   , max_high            :: Interval x
+	-- ^ An __'Interval' with the max 'high' 'Limit'__
+	--   (which may be a different 'Interval'
+	--   as it can have a lower 'low' 'Limit',
+	--   and thus not be the 'max' 'Interval').
+  -}
+   }
+instance Ord x => Monoid (Measure x) where
+	mempty = Measure_Empty
+	
+	Measure_Empty `mappend` i  = i
+	i `mappend` Measure_Empty  = i
+	_i `mappend` j = Measure (max_high_of_max_low j)
+  {- NOTE: not useful in the particular case of '..<..'-ordered 'Interval's
+	i `mappend` j =
+		Measure (max_high_of_max_low j) $
+		case compare_without_adherence (high (max_high i)) (high (max_high j)) of
+		 LT -> max_high j
+		 EQ ->
+			case (adherence (high (max_high i)), adherence (high (max_high j))) of
+			 (In , In)  -> max_high i
+			 (In , Out) -> max_high i
+			 (Out, In)  -> max_high j
+			 (Out, Out) -> max_high i
+		 GT -> max_high i
+	-}
+instance Ord x => FT.Measured (Measure x) (Interval x) where
+	measure = Measure
+
+empty :: Ord x => Sieve x
+empty = Sieve FT.empty
+
+-- | Return the 'True' iif. the given 'Sieve' is 'empty'.
+null :: Ord x => Sieve x -> Bool
+null (Sieve ft) = FT.null ft
+
+singleton :: Ord x => Interval x -> Sieve x
+singleton = Sieve . FT.singleton
+
+-- | Return an 'Interval' with:
+--
+-- * the 'Interval.low'  'Interval.Limit' of the 'min' 'Interval',
+-- * the 'Interval.high' 'Interval.Limit' of the 'max' 'Interval'.
+interval :: Ord x => Sieve x -> Maybe (Interval x)
+interval (Sieve ft) =
+	case FT.viewl ft of
+	 FT.EmptyL -> Nothing
+	 -- l :< ls | FT.null ls -> Just l
+	 l :< _ ->
+		case FT.viewr ft of
+		 FT.EmptyR -> Nothing
+		 _ :> r    -> Just $ Interval (low l, high r)
+
+-- | All the 'Interval's of the 'Sieve' in '..<<..' order.
+intervals :: Ord x => Sieve x -> [Interval x]
+intervals (Sieve t) = Foldable.toList t
+
+-- * Union
+
+-- | Return a 'Sieve' merging the given 'Sieve's with 'Interval.union'.
+union :: Ord x => Sieve x -> Sieve x -> Sieve x
+union (Sieve s0) (Sieve s1) =
+	Sieve (merge s0 s1)
+	where
+		merge is js =
+			case FT.viewl is of
+			 FT.EmptyL -> js
+			 i :< gt_i ->
+				let (js_not_away_lt_i, js_away_gt_i ) = FT.split (      (i ..<<..) . max_high_of_max_low) js in
+				let (js_away_lt_i    , js_not_away_i) = FT.split (not . (..<<.. i) . max_high_of_max_low) js_not_away_lt_i in
+				js_away_lt_i ><
+				 -- NOTE: flip merge when possible
+				 --       (i.e. when high i is majoring high-s of intersecting Interval-s)
+				 --       to preserve complexity over commutativity.
+				case FT.viewl js_not_away_i of
+				 FT.EmptyL -> i <| merge js_away_gt_i gt_i
+				 lu :< us ->
+					case FT.viewr us of
+					 FT.EmptyR ->
+						let u = lu in
+						case position i u of
+						 (Adjacent, LT) -> merge gt_i (Interval (low i, high u) <| js_away_gt_i) -- flip: NO
+						 (Overlap , LT) -> merge gt_i (Interval (low i, high u) <| js_away_gt_i) -- flip: NO
+						 (Prefix  , LT) -> merge gt_i (Interval (low i, high u) <| js_away_gt_i) -- flip: NO
+						 (Include , GT) -> merge gt_i (u                        <| js_away_gt_i) -- flip: NO
+						 (Suffixed, LT) -> i                        <| merge js_away_gt_i gt_i   -- flip: YES
+						 (Include , LT) -> i                        <| merge js_away_gt_i gt_i   -- flip: YES
+						 (Equal   , _ ) -> i                        <| merge js_away_gt_i gt_i   -- flip: YES
+						 (Adjacent, GT) -> Interval (low u, high i) <| merge js_away_gt_i gt_i   -- flip: YES
+						 (Overlap , GT) -> Interval (low u, high i) <| merge js_away_gt_i gt_i   -- flip: YES
+						 (Prefix  , GT) -> Interval (low u, high i) <| merge js_away_gt_i gt_i   -- flip: YES
+						 (Suffixed, GT) -> Interval (low u, high i) <| merge js_away_gt_i gt_i   -- flip: YES
+						 _              -> assert False undefined
+					 _ :> hu ->
+						let l = low $
+							case position i lu of
+							 (Adjacent, GT) -> lu
+							 (Overlap , GT) -> lu
+							 (Prefix  , GT) -> lu
+							 (Suffixed, GT) -> lu
+							 _              -> i in
+						case position i hu of
+						 (Adjacent, LT) -> merge gt_i (Interval (l, high hu) <| js_away_gt_i) -- flip: NO
+						 (Overlap , LT) -> merge gt_i (Interval (l, high hu) <| js_away_gt_i) -- flip: NO
+						 (Prefix  , LT) -> merge gt_i (Interval (l, high hu) <| js_away_gt_i) -- flip: NO
+						 _              -> Interval (l, high i) <| merge js_away_gt_i gt_i    -- flip: YES
+
+-- | Return a 'Sieve' merging the 'Interval's in the given 'Foldable' with 'Interval.union'.
+from_Foldable :: (Foldable f, Ord x) => f (Interval x) -> Sieve x
+from_Foldable = Foldable.foldr (union . singleton) empty
+
+-- * Intersection
+
+-- | Return a 'Sieve' merging the given 'Sieve's with 'Interval.intersection'.
+intersection :: Ord x => Sieve x -> Sieve x -> Sieve x
+intersection (Sieve s0) (Sieve s1) =
+	Sieve (merge s0 s1)
+	where
+		intersect i j = fromMaybe (assert False undefined) $ Interval.intersection i j
+		merge is js =
+			case FT.viewl is of
+			 FT.EmptyL -> FT.empty
+			 i :< gt_i ->
+				let (_, js_not_lt_i)       = FT.split (not . (..<.. i) . max_high_of_max_low) js in
+				let (js_intersecting_i, _) = FT.split (      (i ..<..) . max_high_of_max_low) js_not_lt_i in
+				case FT.viewl js_intersecting_i of
+				 li :< li' ->
+					intersect li i <|
+					case FT.viewr li' of
+					 hi' :> hi -> hi' |> intersect i hi
+					 _         -> li'
+					><  merge js_not_lt_i gt_i
+				 _ -> merge js_not_lt_i gt_i
+				 -- NOTE: swap merging to preserve complexity over commutativity
+
+-- | All 'Interval's having a non-'Nothing' 'Interval.intersection' with the given 'Interval',
+-- in '..<<..' order.
+intersecting :: Ord x => Interval x -> Sieve x -> [Interval x]
+intersecting i = Foldable.toList . unSieve . intersection (singleton i)
+
+-- * Complement
+
+-- | Return the 'Sieve' spanning over all the values not within the given 'Sieve'.
+complement :: (Ord x, Bounded (Interval.Limit x)) => Sieve x -> Sieve x
+complement = complement_with (Interval (minBound, maxBound))
+
+-- | Return the 'Sieve' spanning over all the values not within the given 'Sieve',
+--   but within the given 'Interval' which MUST be 'Interval.onto' every 'Interval' inside the 'Sieve'.
+complement_with :: Ord x => Interval x -> Sieve x -> Sieve x
+complement_with b (Sieve s) =
+	let (last_low, c) =
+		Foldable.foldr
+		 (\i (previous_low, ft) ->
+			( low i
+			, if (Interval.HH $ high i) < (Interval.HH $ high b)
+				then Interval (flip_limit $ high i, flip_limit previous_low) <| ft
+				else ft
+			))
+		 (flip_limit $ high b, FT.empty) s in
+	Sieve $
+	case compare (Interval.LL $ low b) (Interval.LL last_low) of
+	 LT -> Interval (low b, flip_limit last_low) <| c
+	 EQ | low b == high b && FT.null s -> FT.singleton b
+	 _ -> c
diff --git a/Data/Interval/Sieve/Test.hs b/Data/Interval/Sieve/Test.hs
new file mode 100644
--- /dev/null
+++ b/Data/Interval/Sieve/Test.hs
@@ -0,0 +1,298 @@
+{-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TupleSections #-}
+module Sieve.Test where
+
+import Data.Function (($), (.), flip, on)
+import Data.Functor ((<$>))
+import Data.List (concatMap, foldl, foldr, unwords, reverse)
+import Data.Maybe (Maybe(..), fromJust)
+import Data.Monoid ((<>))
+import Prelude (Integer)
+import Test.Tasty
+import Test.Tasty.HUnit
+import Text.Show (Show(..))
+
+import qualified Data.Interval as Interval
+import qualified Data.Interval.Sieve as Interval.Sieve
+
+tests :: TestTree
+tests = testGroup "Sieve"
+ [ testGroup "union" $
+	concatMap
+	 (\(mis, me) ->
+		let is = fromJust <$> mis in
+		let e  = fromJust <$> me in
+		let sil = foldl
+			 (flip (Interval.Sieve.union . Interval.Sieve.singleton))
+			 Interval.Sieve.empty is in
+		let sir = foldr
+			 (Interval.Sieve.union . Interval.Sieve.singleton)
+			 Interval.Sieve.empty is in
+		[ testCase (unwords $ (show . Interval.Pretty) <$> is) $
+			Interval.Sieve.intervals sil @?= e
+		, testCase (unwords $ (show . Interval.Pretty) <$> reverse is) $
+			Interval.Sieve.intervals sir @?= e
+		]
+	 )
+	 [ ( [ (Interval.<=..<)  0 (5::Integer)
+			 , (Interval.<=..<=) 5 9
+			 ]
+		 , [ (Interval.<=..<=) 0 9 ]
+		 )
+	 , ( [ (Interval.<=..<=) 0 5
+			 , (Interval.<=..<=) 0 9
+			 ]
+		 , [ (Interval.<=..<=) 0 9 ]
+		 )
+	 , ( [ (Interval.<=..<=) 0 4
+			 , (Interval.<=..<=) 5 9
+			 , (Interval.<=..<=) 3 6
+			 ]
+		 , [ (Interval.<=..<=) 0 9 ]
+		 )
+	 , ( [ (Interval.<=..<=) 1 4
+			 , (Interval.<=..<=) 5 8
+			 ]
+		 , [ (Interval.<=..<=) 1 4
+			 , (Interval.<=..<=) 5 8
+			 ]
+		 )
+	 , ( [ (Interval.<=..<=) 1 8
+			 , (Interval.<=..<=) 0 9
+			 ]
+		 , [ (Interval.<=..<=) 0 9 ]
+		 )
+	 , ( [ (Interval.<=..<=) 1 4
+			 , (Interval.<=..<=) 5 8
+			 , (Interval.<=..<=) 0 9
+			 ]
+		 , [ (Interval.<=..<=) 0 9 ]
+		 )
+	 ] <>
+	concatMap
+	 (\(mis, mjs, me) ->
+		let is = fromJust <$> mis in
+		let js = fromJust <$> mjs in
+		let e  = fromJust <$> me in
+		let iu = foldl
+			 (flip (Interval.Sieve.union . Interval.Sieve.singleton))
+			 Interval.Sieve.empty is in
+		let ju = foldl
+			 (flip (Interval.Sieve.union . Interval.Sieve.singleton))
+			 Interval.Sieve.empty js in
+		[ testCase (unwords ((show . Interval.Pretty) <$> is) <> " u " <>
+				unwords ((show . Interval.Pretty) <$> js)) $
+			Interval.Sieve.intervals (Interval.Sieve.union iu ju) @?= e
+		, testCase (unwords ((show . Interval.Pretty) <$> js) <> " u " <>
+				unwords ((show . Interval.Pretty) <$> is)) $
+			Interval.Sieve.intervals (Interval.Sieve.union ju iu) @?= e
+		]
+	 )
+	 [ ( [ (Interval.<=..<=) 0 (1::Integer)
+		   , (Interval.<=..<=) 2 4
+		   ]
+		 , [ (Interval.<=..<=) 0 3
+		   ]
+		 , [ (Interval.<=..<=) 0 4
+		   ]
+		 )
+	 , ( [ (Interval.<=..<=) 0 1
+		   , (Interval.<=..<=) 2 3
+		   , (Interval.<=..<=) 4 5
+		   , (Interval.<=..<=) 6 7
+		   ]
+		 , [ (Interval.<=..<=) 1 2
+		   , (Interval.<=..<=) 3 4
+		   , (Interval.<=..<=) 5 6
+		   ]
+		 , [ (Interval.<=..<=) 0 7
+		   ]
+		 )
+	 , ( [ (Interval.<=..<=) 0 1
+		   , (Interval.<=..<=) 2 3
+		   ]
+		 , [ (Interval.<=..<=) 4 5
+		   ]
+		 , [ (Interval.<=..<=) 0 1
+		   , (Interval.<=..<=) 2 3
+		   , (Interval.<=..<=) 4 5
+		   ]
+		 )
+	 , ( [ (Interval.<=..<=) 0 1
+		   , (Interval.<=..<=) 4 5
+		   ]
+		 , [ (Interval.<=..<=) 2 3
+		   ]
+		 , [ (Interval.<=..<=) 0 1
+		   , (Interval.<=..<=) 2 3
+		   , (Interval.<=..<=) 4 5
+		   ]
+		 )
+	 ]
+ , testGroup "intersection" $
+	concatMap
+	 (\(mis, mjs, me) ->
+		let is = fromJust <$> mis in
+		let js = fromJust <$> mjs in
+		let e  = fromJust <$> me in
+		let iu = foldl
+			 (flip (Interval.Sieve.union . Interval.Sieve.singleton))
+			 Interval.Sieve.empty is in
+		let ju = foldl
+			 (flip (Interval.Sieve.union . Interval.Sieve.singleton))
+			 Interval.Sieve.empty js in
+		[ testCase (unwords ((show . Interval.Pretty) <$> is) <> " n " <>
+				unwords ((show . Interval.Pretty) <$> js)) $
+			Interval.Sieve.intervals (Interval.Sieve.intersection iu ju) @?= e
+		, testCase (unwords ((show . Interval.Pretty) <$> js) <> " n " <>
+				unwords ((show . Interval.Pretty) <$> is)) $
+			Interval.Sieve.intervals (Interval.Sieve.intersection ju iu) @?= e
+		]
+	 )
+	 [ ( [ (Interval.<=..<)  0 (5::Integer) ]
+		 , [ (Interval.<=..<=) 5 9 ]
+		 , [ ]
+		 )
+	 , ( [ (Interval.<=..<=) 0 5 ]
+		 , [ (Interval.<=..<=) 5 9 ]
+		 , [ (Interval.<=..<=) 5 5 ]
+		 )
+	 , ( [ (Interval.<=..<=) 0 5 ]
+		 , [ (Interval.<=..<=) 0 9 ]
+		 , [ (Interval.<=..<=) 0 5 ]
+		 )
+	 , ( [ (Interval.<=..<=) 0 4
+			 , (Interval.<=..<=) 5 9
+			 ]
+		 , [ (Interval.<=..<=) 3 6 ]
+		 , [ (Interval.<=..<=) 3 4
+			 , (Interval.<=..<=) 5 6
+			 ]
+		 )
+	 , ( [ (Interval.<=..<=) 1 4
+			 , (Interval.<=..<=) 6 8
+			 ]
+		 , [ (Interval.<=..<=) 2 3
+			 , (Interval.<=..<=) 5 7
+			 ]
+		 , [ (Interval.<=..<=) 2 3
+			 , (Interval.<=..<=) 6 7
+			 ]
+		 )
+	 ]
+ , testGroup "complement" $
+	concatMap
+	 (\(mis, me) ->
+		let is = fromJust <$> mis in
+		let e  = fromJust <$> me in
+		let iu = foldl
+			 (flip (Interval.Sieve.union . Interval.Sieve.singleton))
+			 Interval.Sieve.empty is in
+		[ testCase (show (Interval.Pretty $
+			Interval.Sieve.fmap_interval
+				(Interval.fmap_unsafe Interval.Pretty) iu)) $
+			Interval.Sieve.intervals (Interval.Sieve.complement iu) @?= e
+		]
+	 )
+	 [ ( [ ((Interval.<=..<)  `on` Interval.Limited) 0 (5::Integer)
+			 , ((Interval.<=..<=) `on` Interval.Limited) 5 9
+			 ]
+		 , [ Just $ (Interval...<) 0
+			 , Just $ (Interval.<..) 9
+			 ]
+		 )
+	 , ( [ Just Interval.unlimited ]
+		 , [ ]
+		 )
+	 , ( [ ]
+		 , [ Just Interval.unlimited ]
+		 )
+	 , ( [ Just $ (Interval...<) 0
+			 , Just $ (Interval.<..) 0
+			 ]
+		 , [ Just $ Interval.point $ Interval.Limited 0
+			 ]
+		 )
+	 , ( [ ((Interval.<=..<) `on` Interval.Limited) 0 1
+			 , ((Interval.<=..<) `on` Interval.Limited) 2 3
+			 , ((Interval.<..<=) `on` Interval.Limited) 3 4
+			 ]
+		 , [ Just $ (Interval...<) 0
+			 ,       ((Interval.<=..<) `on` Interval.Limited) 1 2
+			 , Just $ Interval.point $ Interval.Limited 3
+			 , Just $ (Interval.<..) 4
+			 ]
+		 )
+	 ]
+ , testGroup "complement_with" $
+	concatMap
+	 (\(mib, mis, me) ->
+		let ib = fromJust mib in
+		let is = fromJust <$> mis in
+		let e  = fromJust <$> me in
+		let iu = foldl
+			 (flip (Interval.Sieve.union . Interval.Sieve.singleton))
+			 Interval.Sieve.empty is in
+		[ testCase (show (Interval.Pretty iu)) $
+			Interval.Sieve.intervals
+			 (Interval.Sieve.complement_with ib iu) @?= e
+		]
+	 )
+	 [ ( (Interval.<=..<=)   (-10) (10::Integer)
+		 , [ (Interval.<=..<)  0 5
+			 , (Interval.<=..<=) 5 9
+			 ]
+		 , [ (Interval.<=..<) (-10) 0
+			 , (Interval.<..<=) 9 10
+			 ]
+		 )
+	 , ( (Interval.<=..<=) (-10) 10
+		 , [ (Interval.<=..<=) (-10) 10 ]
+		 , [ ]
+		 )
+	 , ( (Interval.<=..<=) (-10) 10
+		 , [ ]
+		 , [ (Interval.<=..<=) (-10) 10 ]
+		 )
+	 , ( (Interval.<=..<=) (-10) 10
+		 , [ (Interval.<=..<) (-10) 0
+			 , (Interval.<..<=) 0 10
+			 ]
+		 , [ Just $ Interval.point 0
+			 ]
+		 )
+	 , ( (Interval.<=..<=) (-10) 10
+		 , [ Just $ Interval.point 0
+			 ]
+		 , [ (Interval.<=..<) (-10) 0
+			 , (Interval.<..<=) 0 10
+			 ]
+		 )
+	 , ( (Interval.<=..<=) 0 10
+		 , [ (Interval.<..<=) 0 10
+			 ]
+		 , [ Just $ Interval.point 0
+			 ]
+		 )
+	 , ( (Interval.<=..<=) 0 10
+		 , [ (Interval.<=..<) 0 10
+			 ]
+		 , [ Just $ Interval.point 10
+			 ]
+		 )
+	 , ( Just $ Interval.point 0
+		 , [
+			 ]
+		 , [ Just $ Interval.point 0
+			 ]
+		 )
+	 , ( Just $ Interval.point 0
+		 , [ Just $ Interval.point 0
+			 ]
+		 , [
+			 ]
+		 )
+	 ]
+ ]
diff --git a/Data/Interval/Test.hs b/Data/Interval/Test.hs
new file mode 100644
--- /dev/null
+++ b/Data/Interval/Test.hs
@@ -0,0 +1,151 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+module Test where
+
+import Data.Function (($), (.))
+import qualified Data.List as List
+import Data.Maybe (Maybe(..), fromJust)
+import Data.Monoid ((<>))
+import Data.Ord (Ordering(..))
+import Prelude (Integer)
+import System.IO (IO)
+import Test.Tasty
+import Test.Tasty.HUnit
+import Text.Show (Show(..))
+
+import qualified Data.Interval as Interval
+import qualified Sieve.Test as Sieve
+
+main :: IO ()
+main =
+	defaultMain $
+	testGroup "Interval"
+	 [ testGroup "position" $
+		List.concatMap
+		 (\(mi, mj, p) ->
+			let i = fromJust mi in
+			let j = fromJust mj in
+			let (le, ge) =
+				case p of
+				 Interval.Equal -> (EQ, EQ)
+				 _ -> (LT, GT) in
+			[ testCase ((show . Interval.Pretty) i <> " " <> (show . Interval.Pretty) j) $
+				Interval.position i j @?= (p, le)
+			, testCase ((show . Interval.Pretty) j <> " " <> (show . Interval.Pretty) i) $
+				Interval.position j i @?= (p, ge)
+			]
+		 )
+		 [ ( (Interval.<..<) 0 (4::Integer)
+			 , (Interval.<..<) 5 9
+			 , Interval.Away )
+		 , ( (Interval.<..<)  0 4
+			 , (Interval.<=..<) 4 9
+			 , Interval.Adjacent )
+		 , ( (Interval.<..<) 0 5
+			 , (Interval.<..<) 4 9
+			 , Interval.Overlap )
+		 , ( (Interval.<..<) 0 5
+			 , (Interval.<..<) 0 9
+			 , Interval.Prefix )
+		 , ( (Interval.<..<) 0 9
+			 , (Interval.<..<) 1 8
+			 , Interval.Include )
+		 , ( (Interval.<..<) 0 9
+			 , (Interval.<..<) 5 9
+			 , Interval.Suffixed )
+		 , ( (Interval.<..<) 0 9
+			 , (Interval.<..<) 0 9
+			 , Interval.Equal )
+		 , ( (Interval.<..<) 0 9
+			 , (Interval.<..<=) 0 9
+			 , Interval.Prefix )
+		 , ( (Interval.<=..<) 0 9
+			 , (Interval.<..<) 0 9
+			 , Interval.Suffixed )
+		 , ( (Interval.<=..<=) 0 9
+			 , (Interval.<..<) 0 9
+			 , Interval.Include )
+		 ]
+	 , testGroup "intersection" $
+		List.concatMap
+		 (\(mi, mj, e) ->
+			let i = fromJust mi in
+			let j = fromJust mj in
+			[ testCase ((show . Interval.Pretty) i <> " " <> (show . Interval.Pretty) j) $
+				Interval.intersection i j @?= e
+			, testCase ((show . Interval.Pretty) j <> " " <> (show . Interval.Pretty) i) $
+				Interval.intersection j i @?= e
+			]
+		 )
+		 [ ( (Interval.<..<) 0 (4::Integer)
+			 , (Interval.<..<) 5 9
+			 , Nothing )
+		 , ( (Interval.<..<=) 0 5
+			 , (Interval.<=..<) 5 9
+			 , (Interval.<=..<=) 5 5 )
+		 , ( (Interval.<..<) 0 6
+			 , (Interval.<..<) 4 9
+			 , (Interval.<..<) 4 6 )
+		 , ( (Interval.<..<=) 0 6
+			 , (Interval.<=..<) 4 9
+			 , (Interval.<=..<=) 4 6 )
+		 , ( (Interval.<..<) 0 6
+			 , (Interval.<=..<) 4 9
+			 , (Interval.<=..<) 4 6 )
+		 , ( (Interval.<..<=) 0 6
+			 , (Interval.<..<) 4 9
+			 , (Interval.<..<=) 4 6 )
+		 , ( (Interval.<..<) 0 9
+			 , (Interval.<..<) 0 9
+			 , (Interval.<..<) 0 9 )
+		 , ( (Interval.<=..<) 0 9
+			 , (Interval.<..<=) 0 9
+			 , (Interval.<..<) 0 9 )
+		 , ( (Interval.<..<=) 0 9
+			 , (Interval.<=..<) 0 9
+			 , (Interval.<..<) 0 9 )
+		 , ( (Interval.<=..<=) 0 9
+			 , (Interval.<=..<=) 0 9
+			 , (Interval.<=..<=) 0 9 )
+		 ]
+	 , testGroup "union" $
+		List.concatMap
+		(\(mi, mj, e) ->
+			let i = fromJust mi in
+			let j = fromJust mj in
+			[ testCase ((show . Interval.Pretty) i <> " " <> (show . Interval.Pretty) j) $
+				Interval.union i j @?= e
+			, testCase ((show . Interval.Pretty) j <> " " <> (show . Interval.Pretty) i) $
+				Interval.union j i @?= e
+			]
+		 )
+		 [ ( (Interval.<..<) 0 (4::Integer)
+			 , (Interval.<..<) 5 9
+			 , Nothing )
+		 , ( (Interval.<..<=) 0 5
+			 , (Interval.<..<) 5 9
+			 , (Interval.<..<) 0 9 )
+		 , ( (Interval.<..<) 0 5
+			 , (Interval.<=..<) 5 9
+			 , (Interval.<..<) 0 9 )
+		 , ( (Interval.<..<=) 0 5
+			 , (Interval.<=..<) 5 9
+			 , (Interval.<..<) 0 9 )
+		 , ( (Interval.<..<) 0 6
+			 , (Interval.<..<) 4 9
+			 , (Interval.<..<) 0 9 )
+		 , ( (Interval.<..<) 0 9
+			 , (Interval.<..<) 0 9
+			 , (Interval.<..<) 0 9 )
+		 , ( (Interval.<=..<) 0 9
+			 , (Interval.<..<=) 0 9
+			 , (Interval.<=..<=) 0 9 )
+		 , ( (Interval.<..<=) 0 9
+			 , (Interval.<=..<) 0 9
+			 , (Interval.<=..<=) 0 9 )
+		 , ( (Interval.<=..<=) 0 9
+			 , (Interval.<=..<=) 0 9
+			 , (Interval.<=..<=) 0 9 )
+		 ]
+	 , Sieve.tests
+	 ]
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/interval.cabal b/interval.cabal
new file mode 100644
--- /dev/null
+++ b/interval.cabal
@@ -0,0 +1,92 @@
+author: Julien Moutinho <julm+haskell+interval@autogeree.net>
+-- bug-reports: http://bug.autogeree.net/haskell/interval/
+build-type: Simple
+cabal-version: >= 1.8
+category: Data Structures
+-- data-dir: data
+-- data-files: 
+description: Data types to represent, compare and combine intervals with adherences.
+ .
+ See also:
+ .
+ - https://hackage.haskell.org/package/data-interval
+ - https://hackage.haskell.org/package/intervals
+extra-source-files:
+  stack.yaml
+extra-tmp-files:
+-- homepage: http://pad.autogeree.net/informatique/haskell/interval/
+license: GPL-3
+license-file: COPYING
+maintainer: Julien Moutinho <julm+haskell+interval@autogeree.net>
+name: interval
+stability: experimental
+synopsis: Intervals with adherences.
+tested-with: GHC==7.10.3
+version: 1.20160821
+
+source-repository head
+  location: git://git.autogeree.net/haskell/interval
+  type:     git
+
+Flag dev
+  Default:     False
+  Description: Turn on development settings.
+  Manual:      True
+
+Flag dump
+  Default:     False
+  Description: Dump some intermediate files.
+  Manual:      True
+
+Flag prof
+  Default:     False
+  Description: Turn on profiling settings.
+  Manual:      True
+
+Flag threaded
+  Default:     False
+  Description: Enable threads.
+  Manual:      True
+
+Library
+  extensions: NoImplicitPrelude
+  ghc-options: -Wall -fno-warn-tabs
+  if flag(dev)
+    cpp-options: -DDEVELOPMENT
+    ghc-options:
+  if flag(dump)
+    ghc-options: -ddump-simpl -ddump-stg -ddump-to-file
+  if flag(prof)
+    cpp-options: -DPROFILING
+    ghc-options: -fprof-auto
+  -- default-language: Haskell2010
+  exposed-modules:
+    Data.Interval
+    Data.Interval.Sieve
+  build-depends:
+    base >= 4.6 && < 5
+    , deepseq
+    , fingertree
+
+Test-Suite interval-test
+  type: exitcode-stdio-1.0
+  -- default-language: Haskell2010
+  extensions: NoImplicitPrelude
+  ghc-options: -Wall -fno-warn-tabs
+               -main-is Test
+  hs-source-dirs: Data/Interval
+  main-is: Test.hs
+  other-modules:
+    Sieve.Test
+  if flag(threaded)
+    ghc-options: -threaded -rtsopts -with-rtsopts=-N
+  if flag(dev)
+    cpp-options: -DDEVELOPMENT
+  if flag(prof)
+    cpp-options: -DPROFILING
+    ghc-options: -fprof-auto
+  build-depends:
+    base >= 4.6 && < 5
+    , interval
+    , tasty >= 0.11
+    , tasty-hunit
diff --git a/stack.yaml b/stack.yaml
new file mode 100644
--- /dev/null
+++ b/stack.yaml
@@ -0,0 +1,6 @@
+resolver: lts-6.12
+flags: {}
+packages:
+- '.'
+extra-deps:
+extra-package-dbs: []
