diff --git a/Setup.lhs b/Setup.lhs
new file mode 100644
--- /dev/null
+++ b/Setup.lhs
@@ -0,0 +1,5 @@
+#!/usr/bin/env runhaskell
+
+> import Distribution.Simple
+> main = defaultMain
+
diff --git a/oneOfN.cabal b/oneOfN.cabal
new file mode 100644
--- /dev/null
+++ b/oneOfN.cabal
@@ -0,0 +1,27 @@
+name:                   oneOfN
+version:                0.1
+stability:              provisional
+
+cabal-version:          >= 1.6
+build-type:             Simple
+
+author:                 James Cook <mokus@deepbondi.net>
+maintainer:             James Cook <mokus@deepbondi.net>
+license:                PublicDomain
+homepage:               https://github.com/mokus0/oneOfN
+
+category:               Data
+synopsis:               Anonymous coproduct type
+description:            Anonymous coproduct type (generalization of Either to
+                        choices among other than 2 cases)
+
+extra-source-files:     src-TH/Data/OneOfN.hs
+
+source-repository head
+  type:                 git
+  location:             git://github.com/mokus0/oneOfN.git
+
+Library
+  hs-source-dirs:       src
+  exposed-modules:      Data.OneOfN
+  build-depends:        base >= 3 && <5
diff --git a/src-TH/Data/OneOfN.hs b/src-TH/Data/OneOfN.hs
new file mode 100644
--- /dev/null
+++ b/src-TH/Data/OneOfN.hs
@@ -0,0 +1,52 @@
+{-# LANGUAGE TemplateHaskell, DeriveDataTypeable #-}
+module Data.OneOfN where
+
+import Data.Char (toLower)
+import Data.Data (Data, Typeable)
+import Language.Haskell.TH
+
+$( do
+    let minN = 2
+        maxN = 20
+        maxTypeableN = 7
+        lc []     = []
+        lc (c:cs) = toLower c : cs
+        
+        -- same naming scheme as HaXml, but start using numerals at 10,
+        -- as per (one) standard English writing convention.
+        nOfM n m = concat [numWord n, "Of", show m]
+            where
+                numWords = ["Zero","One","Two","Three","Four","Five",
+                            "Six","Seven","Eight","Nine"]
+                numWord n
+                    | n < length numWords   = numWords !! n
+                    | otherwise             = "Choice" ++ show n
+        typeVarName n = mkName ("t" ++ show n)
+        
+        mkOneOfN m = do
+            -- the data declaration
+            ty <- dataD (cxt []) (mkName (nOfM 1 m))
+                (map (PlainTV . typeVarName) [1..m]) 
+                [ normalC (mkName (nOfM n m)) [strictType isStrict (varT (typeVarName n))] 
+                    | n <- [1..m]]
+                ([''Eq, ''Ord, ''Read, ''Show]
+                    ++ if m <= maxTypeableN then [''Data, ''Typeable] else [])
+            
+            -- a "folding" function, like 'Prelude.either'
+            let f n = mkName ("f" ++ show n)
+                it  = mkName "it"
+                x   = mkName "x"
+            fun <- funD (mkName (lc (nOfM 1 m)))
+                [ clause
+                    (map (varP . f) [1..m] ++ [varP it])
+                    (normalB (caseE (varE it)
+                        [ match (conP (mkName (nOfM n m)) [varP x])
+                            (normalB (appE (varE (f n)) (varE x))) []
+                        | n <- [1..m]
+                        ])) []
+                ]
+            
+            return [ty, fun]
+    
+    fmap concat (mapM mkOneOfN [minN..maxN])
+ )
diff --git a/src/Data/OneOfN.hs b/src/Data/OneOfN.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/OneOfN.hs
@@ -0,0 +1,537 @@
+{-# LANGUAGE DeriveDataTypeable #-}
+-- Initially generated by TH (src-TH/Data/OneOfN.hs)
+module Data.OneOfN where
+
+import Data.Data (Data, Typeable)
+
+data OneOf2 t1 t2
+    = OneOf2 !t1
+    | TwoOf2 !t2
+    deriving (Eq, Ord, Read, Show, Data, Typeable)
+
+oneOf2 f1 f2 it
+  = case it of
+      OneOf2 x -> f1 x
+      TwoOf2 x -> f2 x
+
+data OneOf3 t1 t2 t3
+    = OneOf3   !t1
+    | TwoOf3   !t2
+    | ThreeOf3 !t3
+    deriving (Eq, Ord, Read, Show, Data, Typeable)
+
+oneOf3 f1 f2 f3 it
+  = case it of
+      OneOf3   x -> f1 x
+      TwoOf3   x -> f2 x
+      ThreeOf3 x -> f3 x
+
+data OneOf4 t1 t2 t3 t4
+    = OneOf4   !t1
+    | TwoOf4   !t2
+    | ThreeOf4 !t3
+    | FourOf4  !t4
+    deriving (Eq, Ord, Read, Show, Data, Typeable)
+
+oneOf4 f1 f2 f3 f4 it
+  = case it of
+      OneOf4   x -> f1 x
+      TwoOf4   x -> f2 x
+      ThreeOf4 x -> f3 x
+      FourOf4  x -> f4 x
+
+data OneOf5 t1 t2 t3 t4 t5
+    = OneOf5   !t1
+    | TwoOf5   !t2
+    | ThreeOf5 !t3
+    | FourOf5  !t4
+    | FiveOf5  !t5
+    deriving (Eq, Ord, Read, Show, Data, Typeable)
+
+oneOf5 f1 f2 f3 f4 f5 it
+  = case it of
+      OneOf5   x -> f1 x
+      TwoOf5   x -> f2 x
+      ThreeOf5 x -> f3 x
+      FourOf5  x -> f4 x
+      FiveOf5  x -> f5 x
+
+data OneOf6 t1 t2 t3 t4 t5 t6
+    = OneOf6   !t1
+    | TwoOf6   !t2
+    | ThreeOf6 !t3
+    | FourOf6  !t4
+    | FiveOf6  !t5
+    | SixOf6   !t6
+    deriving (Eq, Ord, Read, Show, Data, Typeable)
+
+oneOf6 f1 f2 f3 f4 f5 f6 it
+  = case it of
+      OneOf6   x -> f1 x
+      TwoOf6   x -> f2 x
+      ThreeOf6 x -> f3 x
+      FourOf6  x -> f4 x
+      FiveOf6  x -> f5 x
+      SixOf6   x -> f6 x
+
+data OneOf7 t1 t2 t3 t4 t5 t6 t7
+    = OneOf7   !t1
+    | TwoOf7   !t2
+    | ThreeOf7 !t3
+    | FourOf7  !t4
+    | FiveOf7  !t5
+    | SixOf7   !t6
+    | SevenOf7 !t7
+    deriving (Eq, Ord, Read, Show, Data, Typeable)
+
+oneOf7 f1 f2 f3 f4 f5 f6 f7 it
+  = case it of
+      OneOf7   x -> f1 x
+      TwoOf7   x -> f2 x
+      ThreeOf7 x -> f3 x
+      FourOf7  x -> f4 x
+      FiveOf7  x -> f5 x
+      SixOf7   x -> f6 x
+      SevenOf7 x -> f7 x
+
+data OneOf8 t1 t2 t3 t4 t5 t6 t7 t8
+    = OneOf8   !t1
+    | TwoOf8   !t2
+    | ThreeOf8 !t3
+    | FourOf8  !t4
+    | FiveOf8  !t5
+    | SixOf8   !t6
+    | SevenOf8 !t7
+    | EightOf8 !t8
+    deriving (Eq, Ord, Read, Show)
+
+oneOf8 f1 f2 f3 f4 f5 f6 f7 f8 it
+  = case it of
+      OneOf8   x -> f1 x
+      TwoOf8   x -> f2 x
+      ThreeOf8 x -> f3 x
+      FourOf8  x -> f4 x
+      FiveOf8  x -> f5 x
+      SixOf8   x -> f6 x
+      SevenOf8 x -> f7 x
+      EightOf8 x -> f8 x
+
+data OneOf9 t1 t2 t3 t4 t5 t6 t7 t8 t9
+    = OneOf9   !t1
+    | TwoOf9   !t2
+    | ThreeOf9 !t3
+    | FourOf9  !t4
+    | FiveOf9  !t5
+    | SixOf9   !t6
+    | SevenOf9 !t7
+    | EightOf9 !t8
+    | NineOf9  !t9
+    deriving (Eq, Ord, Read, Show)
+
+oneOf9 f1 f2 f3 f4 f5 f6 f7 f8 f9 it
+  = case it of
+      OneOf9   x -> f1 x
+      TwoOf9   x -> f2 x
+      ThreeOf9 x -> f3 x
+      FourOf9  x -> f4 x
+      FiveOf9  x -> f5 x
+      SixOf9   x -> f6 x
+      SevenOf9 x -> f7 x
+      EightOf9 x -> f8 x
+      NineOf9  x -> f9 x
+
+data OneOf10 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10
+    = OneOf10      !t1
+    | TwoOf10      !t2
+    | ThreeOf10    !t3
+    | FourOf10     !t4
+    | FiveOf10     !t5
+    | SixOf10      !t6
+    | SevenOf10    !t7
+    | EightOf10    !t8
+    | NineOf10     !t9
+    | Choice10Of10 !t10
+    deriving (Eq, Ord, Read, Show)
+
+oneOf10 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 it
+  = case it of
+      OneOf10      x -> f1 x
+      TwoOf10      x -> f2 x
+      ThreeOf10    x -> f3 x
+      FourOf10     x -> f4 x
+      FiveOf10     x -> f5 x
+      SixOf10      x -> f6 x
+      SevenOf10    x -> f7 x
+      EightOf10    x -> f8 x
+      NineOf10     x -> f9 x
+      Choice10Of10 x -> f10 x
+
+data OneOf11 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11
+    = OneOf11      !t1
+    | TwoOf11      !t2
+    | ThreeOf11    !t3
+    | FourOf11     !t4
+    | FiveOf11     !t5
+    | SixOf11      !t6
+    | SevenOf11    !t7
+    | EightOf11    !t8
+    | NineOf11     !t9
+    | Choice10Of11 !t10
+    | Choice11Of11 !t11
+    deriving (Eq, Ord, Read, Show)
+
+oneOf11 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 it
+  = case it of
+      OneOf11      x -> f1 x
+      TwoOf11      x -> f2 x
+      ThreeOf11    x -> f3 x
+      FourOf11     x -> f4 x
+      FiveOf11     x -> f5 x
+      SixOf11      x -> f6 x
+      SevenOf11    x -> f7 x
+      EightOf11    x -> f8 x
+      NineOf11     x -> f9 x
+      Choice10Of11 x -> f10 x
+      Choice11Of11 x -> f11 x
+
+data OneOf12 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12
+    = OneOf12      !t1
+    | TwoOf12      !t2
+    | ThreeOf12    !t3
+    | FourOf12     !t4
+    | FiveOf12     !t5
+    | SixOf12      !t6
+    | SevenOf12    !t7
+    | EightOf12    !t8
+    | NineOf12     !t9
+    | Choice10Of12 !t10
+    | Choice11Of12 !t11
+    | Choice12Of12 !t12
+    deriving (Eq, Ord, Read, Show)
+
+oneOf12 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 it
+  = case it of
+      OneOf12      x -> f1 x
+      TwoOf12      x -> f2 x
+      ThreeOf12    x -> f3 x
+      FourOf12     x -> f4 x
+      FiveOf12     x -> f5 x
+      SixOf12      x -> f6 x
+      SevenOf12    x -> f7 x
+      EightOf12    x -> f8 x
+      NineOf12     x -> f9 x
+      Choice10Of12 x -> f10 x
+      Choice11Of12 x -> f11 x
+      Choice12Of12 x -> f12 x
+
+data OneOf13 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13
+    = OneOf13      !t1
+    | TwoOf13      !t2
+    | ThreeOf13    !t3
+    | FourOf13     !t4
+    | FiveOf13     !t5
+    | SixOf13      !t6
+    | SevenOf13    !t7
+    | EightOf13    !t8
+    | NineOf13     !t9
+    | Choice10Of13 !t10
+    | Choice11Of13 !t11
+    | Choice12Of13 !t12
+    | Choice13Of13 !t13
+    deriving (Eq, Ord, Read, Show)
+
+oneOf13 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 it
+  = case it of
+      OneOf13      x -> f1 x
+      TwoOf13      x -> f2 x
+      ThreeOf13    x -> f3 x
+      FourOf13     x -> f4 x
+      FiveOf13     x -> f5 x
+      SixOf13      x -> f6 x
+      SevenOf13    x -> f7 x
+      EightOf13    x -> f8 x
+      NineOf13     x -> f9 x
+      Choice10Of13 x -> f10 x
+      Choice11Of13 x -> f11 x
+      Choice12Of13 x -> f12 x
+      Choice13Of13 x -> f13 x
+
+data OneOf14 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 t14
+    = OneOf14      !t1
+    | TwoOf14      !t2
+    | ThreeOf14    !t3
+    | FourOf14     !t4
+    | FiveOf14     !t5
+    | SixOf14      !t6
+    | SevenOf14    !t7
+    | EightOf14    !t8
+    | NineOf14     !t9
+    | Choice10Of14 !t10
+    | Choice11Of14 !t11
+    | Choice12Of14 !t12
+    | Choice13Of14 !t13
+    | Choice14Of14 !t14
+    deriving (Eq, Ord, Read, Show)
+
+oneOf14 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14 it
+  = case it of
+      OneOf14      x -> f1 x
+      TwoOf14      x -> f2 x
+      ThreeOf14    x -> f3 x
+      FourOf14     x -> f4 x
+      FiveOf14     x -> f5 x
+      SixOf14      x -> f6 x
+      SevenOf14    x -> f7 x
+      EightOf14    x -> f8 x
+      NineOf14     x -> f9 x
+      Choice10Of14 x -> f10 x
+      Choice11Of14 x -> f11 x
+      Choice12Of14 x -> f12 x
+      Choice13Of14 x -> f13 x
+      Choice14Of14 x -> f14 x
+
+data OneOf15 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 t14 t15
+    = OneOf15      !t1
+    | TwoOf15      !t2
+    | ThreeOf15    !t3
+    | FourOf15     !t4
+    | FiveOf15     !t5
+    | SixOf15      !t6
+    | SevenOf15    !t7
+    | EightOf15    !t8
+    | NineOf15     !t9
+    | Choice10Of15 !t10
+    | Choice11Of15 !t11
+    | Choice12Of15 !t12
+    | Choice13Of15 !t13
+    | Choice14Of15 !t14
+    | Choice15Of15 !t15
+    deriving (Eq, Ord, Read, Show)
+
+oneOf15 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14 f15 it
+  = case it of
+      OneOf15      x -> f1 x
+      TwoOf15      x -> f2 x
+      ThreeOf15    x -> f3 x
+      FourOf15     x -> f4 x
+      FiveOf15     x -> f5 x
+      SixOf15      x -> f6 x
+      SevenOf15    x -> f7 x
+      EightOf15    x -> f8 x
+      NineOf15     x -> f9 x
+      Choice10Of15 x -> f10 x
+      Choice11Of15 x -> f11 x
+      Choice12Of15 x -> f12 x
+      Choice13Of15 x -> f13 x
+      Choice14Of15 x -> f14 x
+      Choice15Of15 x -> f15 x
+
+data OneOf16 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 t14 t15 t16
+    = OneOf16      !t1
+    | TwoOf16      !t2
+    | ThreeOf16    !t3
+    | FourOf16     !t4
+    | FiveOf16     !t5
+    | SixOf16      !t6
+    | SevenOf16    !t7
+    | EightOf16    !t8
+    | NineOf16     !t9
+    | Choice10Of16 !t10
+    | Choice11Of16 !t11
+    | Choice12Of16 !t12
+    | Choice13Of16 !t13
+    | Choice14Of16 !t14
+    | Choice15Of16 !t15
+    | Choice16Of16 !t16
+    deriving (Eq, Ord, Read, Show)
+
+oneOf16 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14 f15 f16 it
+  = case it of
+      OneOf16      x -> f1 x
+      TwoOf16      x -> f2 x
+      ThreeOf16    x -> f3 x
+      FourOf16     x -> f4 x
+      FiveOf16     x -> f5 x
+      SixOf16      x -> f6 x
+      SevenOf16    x -> f7 x
+      EightOf16    x -> f8 x
+      NineOf16     x -> f9 x
+      Choice10Of16 x -> f10 x
+      Choice11Of16 x -> f11 x
+      Choice12Of16 x -> f12 x
+      Choice13Of16 x -> f13 x
+      Choice14Of16 x -> f14 x
+      Choice15Of16 x -> f15 x
+      Choice16Of16 x -> f16 x
+
+data OneOf17 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 t14 t15 t16 t17
+    = OneOf17      !t1
+    | TwoOf17      !t2
+    | ThreeOf17    !t3
+    | FourOf17     !t4
+    | FiveOf17     !t5
+    | SixOf17      !t6
+    | SevenOf17    !t7
+    | EightOf17    !t8
+    | NineOf17     !t9
+    | Choice10Of17 !t10
+    | Choice11Of17 !t11
+    | Choice12Of17 !t12
+    | Choice13Of17 !t13
+    | Choice14Of17 !t14
+    | Choice15Of17 !t15
+    | Choice16Of17 !t16
+    | Choice17Of17 !t17
+    deriving (Eq, Ord, Read, Show)
+
+oneOf17 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14 f15 f16 f17 it
+  = case it of
+      OneOf17      x -> f1 x
+      TwoOf17      x -> f2 x
+      ThreeOf17    x -> f3 x
+      FourOf17     x -> f4 x
+      FiveOf17     x -> f5 x
+      SixOf17      x -> f6 x
+      SevenOf17    x -> f7 x
+      EightOf17    x -> f8 x
+      NineOf17     x -> f9 x
+      Choice10Of17 x -> f10 x
+      Choice11Of17 x -> f11 x
+      Choice12Of17 x -> f12 x
+      Choice13Of17 x -> f13 x
+      Choice14Of17 x -> f14 x
+      Choice15Of17 x -> f15 x
+      Choice16Of17 x -> f16 x
+      Choice17Of17 x -> f17 x
+
+data OneOf18 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18
+    = OneOf18      !t1
+    | TwoOf18      !t2
+    | ThreeOf18    !t3
+    | FourOf18     !t4
+    | FiveOf18     !t5
+    | SixOf18      !t6
+    | SevenOf18    !t7
+    | EightOf18    !t8
+    | NineOf18     !t9
+    | Choice10Of18 !t10
+    | Choice11Of18 !t11
+    | Choice12Of18 !t12
+    | Choice13Of18 !t13
+    | Choice14Of18 !t14
+    | Choice15Of18 !t15
+    | Choice16Of18 !t16
+    | Choice17Of18 !t17
+    | Choice18Of18 !t18
+    deriving (Eq, Ord, Read, Show)
+
+oneOf18 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14 f15 f16 f17 f18 it
+  = case it of
+      OneOf18      x -> f1 x
+      TwoOf18      x -> f2 x
+      ThreeOf18    x -> f3 x
+      FourOf18     x -> f4 x
+      FiveOf18     x -> f5 x
+      SixOf18      x -> f6 x
+      SevenOf18    x -> f7 x
+      EightOf18    x -> f8 x
+      NineOf18     x -> f9 x
+      Choice10Of18 x -> f10 x
+      Choice11Of18 x -> f11 x
+      Choice12Of18 x -> f12 x
+      Choice13Of18 x -> f13 x
+      Choice14Of18 x -> f14 x
+      Choice15Of18 x -> f15 x
+      Choice16Of18 x -> f16 x
+      Choice17Of18 x -> f17 x
+      Choice18Of18 x -> f18 x
+
+data OneOf19 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19
+    = OneOf19      !t1
+    | TwoOf19      !t2
+    | ThreeOf19    !t3
+    | FourOf19     !t4
+    | FiveOf19     !t5
+    | SixOf19      !t6
+    | SevenOf19    !t7
+    | EightOf19    !t8
+    | NineOf19     !t9
+    | Choice10Of19 !t10
+    | Choice11Of19 !t11
+    | Choice12Of19 !t12
+    | Choice13Of19 !t13
+    | Choice14Of19 !t14
+    | Choice15Of19 !t15
+    | Choice16Of19 !t16
+    | Choice17Of19 !t17
+    | Choice18Of19 !t18
+    | Choice19Of19 !t19
+    deriving (Eq, Ord, Read, Show)
+
+oneOf19 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14 f15 f16 f17 f18 f19 it
+  = case it of
+      OneOf19      x -> f1 x
+      TwoOf19      x -> f2 x
+      ThreeOf19    x -> f3 x
+      FourOf19     x -> f4 x
+      FiveOf19     x -> f5 x
+      SixOf19      x -> f6 x
+      SevenOf19    x -> f7 x
+      EightOf19    x -> f8 x
+      NineOf19     x -> f9 x
+      Choice10Of19 x -> f10 x
+      Choice11Of19 x -> f11 x
+      Choice12Of19 x -> f12 x
+      Choice13Of19 x -> f13 x
+      Choice14Of19 x -> f14 x
+      Choice15Of19 x -> f15 x
+      Choice16Of19 x -> f16 x
+      Choice17Of19 x -> f17 x
+      Choice18Of19 x -> f18 x
+      Choice19Of19 x -> f19 x
+
+data OneOf20 t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 t20
+    = OneOf20      !t1
+    | TwoOf20      !t2
+    | ThreeOf20    !t3
+    | FourOf20     !t4
+    | FiveOf20     !t5
+    | SixOf20      !t6
+    | SevenOf20    !t7
+    | EightOf20    !t8
+    | NineOf20     !t9
+    | Choice10Of20 !t10
+    | Choice11Of20 !t11
+    | Choice12Of20 !t12
+    | Choice13Of20 !t13
+    | Choice14Of20 !t14
+    | Choice15Of20 !t15
+    | Choice16Of20 !t16
+    | Choice17Of20 !t17
+    | Choice18Of20 !t18
+    | Choice19Of20 !t19
+    | Choice20Of20 !t20
+    deriving (Eq, Ord, Read, Show)
+
+oneOf20 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12 f13 f14 f15 f16 f17 f18 f19 f20 it
+  = case it of
+      OneOf20      x -> f1 x
+      TwoOf20      x -> f2 x
+      ThreeOf20    x -> f3 x
+      FourOf20     x -> f4 x
+      FiveOf20     x -> f5 x
+      SixOf20      x -> f6 x
+      SevenOf20    x -> f7 x
+      EightOf20    x -> f8 x
+      NineOf20     x -> f9 x
+      Choice10Of20 x -> f10 x
+      Choice11Of20 x -> f11 x
+      Choice12Of20 x -> f12 x
+      Choice13Of20 x -> f13 x
+      Choice14Of20 x -> f14 x
+      Choice15Of20 x -> f15 x
+      Choice16Of20 x -> f16 x
+      Choice17Of20 x -> f17 x
+      Choice18Of20 x -> f18 x
+      Choice19Of20 x -> f19 x
+      Choice20Of20 x -> f20 x