diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1d0658a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,19 @@
+# binaries
+*
+
+# compilation intermediate files
+*.hi
+*.ho
+
+# vim generates these
+*.swp
+*.swo
+
+# include directories
+!*/
+
+# include files with an extension
+!*.*
+
+# special cases
+!Makefile
diff --git a/Logic/Parse.hs b/Logic/Parse.hs
new file mode 100644
index 0000000..4956bee
--- /dev/null
+++ b/Logic/Parse.hs
@@ -0,0 +1,77 @@
+module Logic.Parse where
+
+import Control.Applicative (Applicative, Alternative(..))
+import Data.Functor (Functor)
+
+newtype Parser output = Parser
+  { runParser :: Input -> Either ParseError (output, Input)
+  }
+
+data Input = Input
+  { inputPos :: Int
+  , inputSeq :: [Char]
+  } deriving (Eq, Show)
+
+mkInput :: [Char] -> Input
+mkInput = Input 0
+
+data ParseError =
+  ParseError Int String
+  deriving (Show)
+
+expected :: String -> Input -> ParseError
+expected thing input = ParseError (inputPos input) $
+  "expected " <> thing <> ", found " <> show (take 20 $ inputSeq input)
+
+eof :: Parser a -> Input -> Either ParseError a
+eof p input = do
+  (result, rest) <- runParser p input
+  case inputSeq rest of
+    [] -> Right result
+    _ -> Left $ expected "end of input" rest
+
+instance Functor Parser where
+  fmap :: (a -> b) -> Parser a -> Parser b
+  fmap f (Parser p) = Parser $ \input -> do
+    (result, rest) <- p input
+    return (f result, rest)
+
+instance Applicative Parser where
+  pure :: a -> Parser a
+  pure result = Parser $ \input -> Right (result, input)
+
+  (Parser p1) <*> (Parser p2) =
+    Parser $ \input -> do
+      (f, rest) <- p1 input
+      (result, rest') <- p2 rest
+      return (f result, rest')
+
+instance Alternative Parser where
+  empty :: Parser a
+  empty = Parser $ const empty
+
+  (Parser p1) <|> (Parser p2) =
+    Parser $ \input -> p1 input <|> p2 input
+
+instance Alternative (Either ParseError) where
+  empty :: Either ParseError a
+  empty = Left $ ParseError 0 "this parser always fails"
+
+  (Right x) <|> _ = Right x
+  (Left _) <|> e = e
+
+parseToken :: String -> Parser String
+parseToken token = Parser parse
+  where
+    n = length token
+    parse input@(Input pos xs)
+      | token == take n xs = Right $ (token,) $ Input (pos + n) (drop n xs)
+      | otherwise = Left $ expected (show token) input
+
+parseIf :: String -> (Char -> Bool) -> Parser Char
+parseIf description check = Parser $ \input ->
+  case inputSeq input of
+    [] -> Left $ ParseError (inputPos input) "unexpected end of input"
+    (char:chars)
+      | check char -> Right $ (char,) $ Input (inputPos input + 1) chars
+      | otherwise -> Left $ expected description input
diff --git a/Logic/Statement.hs b/Logic/Statement.hs
new file mode 100644
index 0000000..09b94ec
--- /dev/null
+++ b/Logic/Statement.hs
@@ -0,0 +1,237 @@
+module Logic.Statement where
+
+import Logic.Parse
+
+import Control.Applicative (Alternative((<|>), some))
+import Data.Char (isAlphaNum)
+import Data.List (intercalate)
+import Data.Either (fromRight)
+import Data.Set (singleton, union, toAscList)
+
+data Statement
+  = Atom String
+  | Not Statement
+  | And Statement Statement
+  | Or Statement Statement
+  | Implies Statement Statement
+  | Iff Statement Statement
+  deriving (Show, Eq)
+
+stmtAtom :: Parser Statement
+stmtAtom = Atom <$> parse
+  where
+    parse = some $ parseIf "statement variable" $ \char -> isAlphaNum char || char == '_'
+
+stmtNot :: Parser Statement
+stmtNot = Not <$> (parseToken "!" *> stmt)
+
+stmtBinary :: Parser Statement
+stmtBinary = parseToken "(" *> body <* parseToken ")"
+  where
+    body = (\s1 f s2 -> f s1 s2) <$> stmt <*> parseConnective <*> stmt
+
+    parseConnective =
+      fmap (const And) (parseToken "&")
+      <|> fmap (const Or) (parseToken "|")
+      <|> fmap (const Implies) (parseToken "->")
+      <|> fmap (const Iff) (parseToken "<->")
+      <|> fail
+
+    fail = Parser $ \input -> Left $ expected "connective" input
+
+stmt :: Parser Statement
+stmt = Parser $ \input ->
+  let
+    parser =
+      case inputSeq input of
+        [] -> fail
+        ('!':_) -> stmtNot
+        ('(':_) -> stmtBinary
+        _ -> stmtAtom <|> fail
+  in runParser parser input
+  where
+    fail = Parser $ \input -> Left $ expected "statement" input
+
+p :: Statement
+p = fromRight undefined $ eof stmt $ mkInput "((a->b)<->!c)"
+
+q :: Statement
+q = fromRight undefined $ eof stmt $ mkInput "(!a<->((!(p->q)&x)|y))"
+
+atoms :: Statement -> [String]
+atoms = toAscList . mkSet
+  where
+    mkSet (Atom key)      = singleton key
+    mkSet (Not s)         = mkSet s
+    mkSet (And s1 s2)     = union (mkSet s1) (mkSet s2)
+    mkSet (Or s1 s2)      = union (mkSet s1) (mkSet s2)
+    mkSet (Implies s1 s2) = union (mkSet s1) (mkSet s2)
+    mkSet (Iff s1 s2)     = union (mkSet s1) (mkSet s2)
+
+eval :: [(String, Bool)] -> Statement -> Either String Bool
+eval assignments = aux
+  where
+    aux (Atom key)      = maybe (Left key) Right $ lookup key assignments
+    aux (Not s)         = not <$> aux s
+    aux (And s1 s2)     = (&&) <$> aux s1 <*> aux s2
+    aux (Or s1 s2)      = (||) <$> aux s1 <*> aux s2
+    aux (Implies s1 s2) = not <$> ((&&) <$> aux s1 <*> (not <$> aux s2))
+    aux (Iff s1 s2)     = (==) <$> aux s1 <*> aux s2
+
+data Bucket
+  = Tautology
+  | Contradiction
+  | Contingent
+  deriving (Eq, Show)
+
+bucket :: Statement -> Bucket
+bucket s
+  | and values = Tautology
+  | all not values = Contradiction
+  | otherwise = Contingent
+  where
+    values = [fromRight undefined $ eval assignments s | assignments <- enumerate $ atoms s]
+
+enumerate :: [a] -> [[(a, Bool)]]
+enumerate keys = map reverse $ aux start
+  where
+    aux assignments = (assignments:) $
+      case next assignments of
+        Nothing -> []
+        Just (assignments') -> aux assignments'
+
+    start = map (, False) keys
+
+    next [] = Nothing
+    next ((key, False):rest) = Just $ (key, True):rest
+    next ((key, True):rest) = ((key, False):) <$> (next rest)
+
+data SerializeFormat
+  = Ascii
+  | Latex
+  deriving (Show, Eq)
+
+data Cell
+  = Main String
+  | NotMain String
+  deriving (Show, Eq)
+
+fromCell :: Cell -> String
+fromCell (Main x) = x
+fromCell (NotMain x) = x
+
+fromCellLatex :: Cell -> String
+fromCellLatex (Main x) = "\\textbf " <> x
+fromCellLatex (NotMain x) = x
+
+isMain :: Cell -> Bool
+isMain (Main _) = True
+isMain _ = False
+
+serializeCells :: SerializeFormat -> Statement -> [Cell]
+serializeCells = aux Main
+  where
+    aux mkCell Ascii = ascii mkCell
+    aux mkCell Latex = latex mkCell
+
+    ascii' = ascii NotMain
+    latex' = latex NotMain
+
+    ascii mkCell (Atom key)      = [mkCell key]
+    ascii mkCell (Not s)         = [mkCell "!"] ++ ascii' s
+    ascii mkCell (And s1 s2)     = connective (mkCell "&") (ascii' s1) (ascii' s2)
+    ascii mkCell (Or s1 s2)      = connective (mkCell "|") (ascii' s1) (ascii' s2)
+    ascii mkCell (Implies s1 s2) = connective (mkCell "->") (ascii' s1) (ascii' s2)
+    ascii mkCell (Iff s1 s2)     = connective (mkCell "<->") (ascii' s1) (ascii' s2)
+
+    latex mkCell (Atom key)      = [mkCell key]
+    latex mkCell (Not s)         = [mkCell "\\neg "] ++ latex' s
+    latex mkCell (And s1 s2)     = connective (mkCell "\\land ") (latex' s1) (latex' s2)
+    latex mkCell (Or s1 s2)      = connective (mkCell "\\lor ") (latex' s1) (latex' s2)
+    latex mkCell (Implies s1 s2) = connective (mkCell "\\to ") (latex' s1) (latex' s2)
+    latex mkCell (Iff s1 s2)     = connective (mkCell "\\leftrightarrow ") (latex' s1) (latex' s2)
+
+    connective middle s1 s2 = [NotMain "("] ++ s1 ++ [middle] ++ s2 ++ [NotMain ")"]
+
+serialize :: SerializeFormat -> Statement -> String
+serialize fmt s = concat $ map fromCell $ serializeCells fmt s
+
+latexTruthTableMainColumnIndex :: Statement -> Int
+latexTruthTableMainColumnIndex s =
+  fst $ head $ filter (\(i, cell) -> isMain cell) $ zip [0..] $ serializeCells Latex s
+
+serializeLatexTruthTableRow :: [(String, Bool)] -> Statement -> Either String [String]
+serializeLatexTruthTableRow ass s = map fromCellLatex <$> latexRow Main ass s
+  where
+    latexRow mkCell ass (Atom key)      = list <$> mkCell <$> toInt <$> eval ass (Atom key)
+    latexRow mkCell ass (Not s)         = (list <$> mkCell <$> toInt <$> not <$> eval ass s) <> latexRow NotMain ass s
+    latexRow mkCell ass (And s1 s2)     = latexRowBinaryConnective (&&) mkCell ass s1 s2
+    latexRow mkCell ass (Or s1 s2)      = latexRowBinaryConnective (||) mkCell ass s1 s2
+    latexRow mkCell ass (Implies s1 s2) = latexRowBinaryConnective implies mkCell ass s1 s2
+    latexRow mkCell ass (Iff s1 s2)     = latexRowBinaryConnective (==) mkCell ass s1 s2
+
+    latexRowBinaryConnective op mkCell ass s1 s2 =
+      (
+        \subrow1 subrow2 result ->
+          [NotMain " "] ++ subrow1 ++ [mkCell $ toInt result] ++ subrow2 ++ [NotMain " "]
+      ) <$>
+      latexRow NotMain ass s1 <*> latexRow NotMain ass s2 <*>
+      (op <$> eval ass s1 <*> eval ass s2)
+
+    toInt :: Bool -> String
+    toInt False = "0"
+    toInt True = "1"
+
+    list :: a -> [a]
+    list x = [x]
+
+    implies :: Bool -> Bool -> Bool
+    implies b1 b2 = not b1 || b2
+
+truthtable :: Statement -> String
+truthtable s = open <> header <> "\\hline\n" <> body <> close
+  where
+    mainIndex = latexTruthTableMainColumnIndex s
+
+    cellsSpec
+      | mainIndex == 0 && length serial <= 1 = "c"
+      | mainIndex == 0 = "c|" <> replicate (length serial - 1) 'c'
+      | mainIndex == length serial - 1 = replicate (length serial - 1) 'c' <> "|c"
+      | otherwise = replicate mainIndex 'c' <> "|c|" <> replicate (length serial - mainIndex - 1) 'c'
+
+    open =
+      "\\begin{tabular}{" <>
+      replicate (length $ atoms s) 'c' <>
+      "||" <>
+      cellsSpec <>
+      "}\n"
+
+    close = "\\end{tabular}\n\n"
+
+    serial :: [Cell]
+    serial = serializeCells Latex s
+
+    header :: String
+    header =
+      intercalate " & " (map dollars $ atoms s) <>
+      " & " <>
+      intercalate " & " (map dollars $ map fromCell serial) <>
+      " \\\\\n"
+
+    dollars :: String -> String
+    dollars string = "$" <> string <> "$"
+
+    body :: String
+    body = concat $ map line $ enumerate $ atoms s
+
+    line assignments =
+      intercalate " & " (bools assignments) <>
+      " &" <>
+      intercalate "&" (cells assignments) <>
+      "\\\\\n"
+
+    bools assignments = [if bool then "1" else "0" | (key, bool) <- assignments]
+
+    cells assignments =
+      (\xs -> [if x /= " " then " " <> x <> " " else " " | x <- xs]) $
+      fromRight undefined $ serializeLatexTruthTableRow assignments s
diff --git a/Main.hs b/Main.hs
index f82b840..1b4a479 100644
--- a/Main.hs
+++ b/Main.hs
@@ -1,313 +1,16 @@
-import Control.Applicative (Applicative, Alternative(..))
-import Data.Char (isAlphaNum)
-import Data.Functor (Functor)
-import Data.List (intercalate)
-import Data.Maybe (fromJust)
-import qualified Data.Set as S
+module Main where
 
-newtype Parser symbol output = Parser
-  { runParser :: [symbol] -> Maybe (output, [symbol])
-  }
+import Logic.Parse (eof, mkInput, ParseError(..))
+import Logic.Statement (stmt)
 
-instance Functor (Parser s) where
-  fmap :: (a -> b) -> Parser s a -> Parser s b
-  fmap f (Parser p) = Parser 
-    { runParser = \xs -> do
-      (result, xs') <- p xs
-      return (f result, xs')
-    }
-
-instance Applicative (Parser s) where
-  pure :: a -> Parser s a
-  pure result = Parser $ \xs -> Just (result, xs)
-
-  (Parser p1) <*> (Parser p2) =
-    Parser $ \xs -> do
-      (f, xs') <- p1 xs
-      (result, xs'') <- p2 xs'
-      return (f result, xs'')
-
-instance Alternative (Parser s) where
-  empty :: Parser s a
-  empty = Parser $ const Nothing
-
-  (Parser p1) <|> (Parser p2) =
-    Parser $ \xs -> p1 xs <|> p2 xs
-
-data Statement
-  = Atom String
-  | Not Statement
-  | And Statement Statement
-  | Or Statement Statement
-  | Implies Statement Statement
-  | Iff Statement Statement
-  deriving (Show, Eq)
-
-parseToken :: String -> Parser Char String
-parseToken token = Parser parse
+main :: IO ()
+main = do
+  line <- getLine
+  either fail print $ eof stmt $ mkInput line
   where
-    n = length token
-    parse xs
-      | token == take n xs = Just (token, drop n xs)
-      | otherwise = Nothing
-
-parseWhile :: (Char -> Bool) -> Parser Char String
-parseWhile check = Parser parse
-  where
-    parse [] = Nothing
-    parse (token:rest)
-      | check token = 
-        case parse rest of
-          Nothing -> Just ([token], rest)
-          Just (tokens, rest') -> Just (token:tokens, rest')
-      | otherwise = Nothing
-
-parseBrackets :: Parser Char a -> Parser Char a
-parseBrackets p = parseToken "(" *> p <* parseToken ")"
-
-parseInfix :: String -> Parser Char a -> Parser Char a -> Parser Char (a, a)
-parseInfix token p1 p2 = (,) <$> (p1 <* parseToken token) <*> p2
-
-parseConnective :: String -> Parser Char a -> Parser Char a -> Parser Char (a, a)
-parseConnective token p1 p2 = parseBrackets $ parseInfix token p1 p2
-
-stmtAtom :: Parser Char Statement
-stmtAtom = Atom <$> parse
-  where
-    parse = parseWhile $ \char -> isAlphaNum char || char == '_'
-
-stmtNot :: Parser Char Statement
-stmtNot = Not <$> (parseToken "!" *> stmt)
-
-stmtAnd :: Parser Char Statement
-stmtAnd = uncurry And <$> parseConnective "&" stmt stmt
-
-stmtOr :: Parser Char Statement
-stmtOr = uncurry Or <$> parseConnective "|" stmt stmt
-
-stmtImplies :: Parser Char Statement
-stmtImplies = uncurry Implies <$> parseConnective "->" stmt stmt
-
-stmtIff :: Parser Char Statement
-stmtIff = uncurry Iff <$> parseConnective "<->" stmt stmt
-
-stmt :: Parser Char Statement
-stmt = stmtAtom <|> stmtNot <|> stmtAnd <|> stmtOr <|> stmtImplies <|> stmtIff
-
-{-
-ghci> runParser stmt "(!a<->((!(p->q)&x)|y))"
-Just (Iff (Not (Atom "a")) (Or (And (Not (Implies (Atom "p") (Atom "q"))) (Atom "x")) (Atom "y")),"")
--}
-
-p :: Statement
-p = fromJust $ fst <$> runParser stmt "((a->b)<->!c)"
-
-q :: Statement
-q = fromJust $ fst <$> runParser stmt "(!a<->((!(p->q)&x)|y))"
-
-atoms :: Statement -> S.Set String
-atoms (Atom key)      = S.singleton key
-atoms (Not s)         = atoms s
-atoms (And s1 s2)     = S.union (atoms s1) (atoms s2)
-atoms (Or s1 s2)      = S.union (atoms s1) (atoms s2)
-atoms (Implies s1 s2) = S.union (atoms s1) (atoms s2)
-atoms (Iff s1 s2)     = S.union (atoms s1) (atoms s2)
-
-eval :: [(String, Bool)] -> Statement -> Maybe Bool
-eval assignments = aux
-  where
-    aux (Atom key)      = lookup key assignments
-    aux (Not s)         = not <$> aux s
-    aux (And s1 s2)     = (&&) <$> aux s1 <*> aux s2
-    aux (Or s1 s2)      = (||) <$> aux s1 <*> aux s2
-    aux (Implies s1 s2) = not <$> ((&&) <$> aux s1 <*> (not <$> aux s2))
-    aux (Iff s1 s2)     = (==) <$> aux s1 <*> aux s2
-
-data Bucket
-  = Tautology
-  | Contradiction
-  | Contingent
-  deriving (Eq, Show)
-
-bucket :: Statement -> Bucket
-bucket s
-  | and values = Tautology
-  | all not values = Contradiction
-  | otherwise = Contingent
-  where
-    atomsList = S.toList $ atoms s
-    values = [fromJust $ eval assignments s | assignments <- enumerate $ atomsList]
-
-enumerate :: [a] -> [[(a, Bool)]]
-enumerate keys = map reverse $ aux start
-  where
-    aux assignments = (assignments:) $
-      case next assignments of
-        Nothing -> []
-        Just (assignments') -> aux assignments'
-
-    start = [(key, False) | key <- keys]
-
-    next [] = Nothing
-    next ((k, False):rest) = Just $ (k, True):rest
-    next ((k, True):rest) = ((k, False):) <$> (next rest)
-
-{-
- ghci> bucket $ fromJust $ fst <$> runParser stmt "(p<->p)"
-Tautology
-ghci> bucket p
-Contingent
-ghci> bucket q
-Contingent
-ghci> bucket $ fromJust $ fst <$> runParser stmt "(p<->!p)"
-Contradiction
-ghci> bucket $ fromJust $ fst <$> runParser stmt "(p|!p)"
-Tautology
-ghci> bucket $ fromJust $ fst <$> runParser stmt "(p->p)"
-Tautology
-ghci> bucket $ fromJust $ fst <$> runParser stmt "(p&!p)"
-Contradiction
-ghci> bucket $ fromJust $ fst <$> runParser stmt "(!(p->q)&!p)"
-Contradiction
-ghci> bucket $ fromJust $ fst <$> runParser stmt "(p|(p->q))"
-Tautology
-ghci> bucket $ fromJust $ fst <$> runParser stmt "((p->q)->(!p->r))"
-Contingent
-ghci> bucket $ fromJust $ fst <$> runParser stmt "(!(a&b)<->(!a|!b))"
-Tautology
-ghci> bucket $ fromJust $ fst <$> runParser stmt "(!(a|b)<->(!a&!b))"
-Tautology
--}
-
-data SerializeFormat
-  = Ascii
-  | Latex
-  deriving (Show, Eq)
-
-data Cell
-  = Main String
-  | NotMain String
-  deriving (Show, Eq)
-
-fromCell :: Cell -> String
-fromCell (Main x) = x
-fromCell (NotMain x) = x
-
-fromCellLatex :: Cell -> String
-fromCellLatex (Main x) = "\\textbf " <> x
-fromCellLatex (NotMain x) = x
-
-isMain :: Cell -> Bool
-isMain (Main _) = True
-isMain _ = False
-
-serializeCells :: SerializeFormat -> Statement -> [Cell]
-serializeCells = aux Main
-  where
-    aux mkCell Ascii = ascii mkCell
-    aux mkCell Latex = latex mkCell
-
-    ascii' = ascii NotMain
-    latex' = latex NotMain
-
-    ascii mkCell (Atom key)      = [mkCell key]
-    ascii mkCell (Not s)         = [mkCell "!"] ++ ascii' s
-    ascii mkCell (And s1 s2)     = connective (mkCell "&") (ascii' s1) (ascii' s2)
-    ascii mkCell (Or s1 s2)      = connective (mkCell "|") (ascii' s1) (ascii' s2)
-    ascii mkCell (Implies s1 s2) = connective (mkCell "->") (ascii' s1) (ascii' s2)
-    ascii mkCell (Iff s1 s2)     = connective (mkCell "<->") (ascii' s1) (ascii' s2)
-
-    latex mkCell (Atom key)      = [mkCell key]
-    latex mkCell (Not s)         = [mkCell "\\neg "] ++ latex' s
-    latex mkCell (And s1 s2)     = connective (mkCell "\\land ") (latex' s1) (latex' s2)
-    latex mkCell (Or s1 s2)      = connective (mkCell "\\lor ") (latex' s1) (latex' s2)
-    latex mkCell (Implies s1 s2) = connective (mkCell "\\to ") (latex' s1) (latex' s2)
-    latex mkCell (Iff s1 s2)     = connective (mkCell "\\leftrightarrow ") (latex' s1) (latex' s2)
-
-    connective middle s1 s2 = [NotMain "("] ++ s1 ++ [middle] ++ s2 ++ [NotMain ")"]
-
-serialize :: SerializeFormat -> Statement -> String
-serialize fmt s = concat $ map fromCell $ serializeCells fmt s
-
-latexTruthTableMainColumnIndex :: Statement -> Int
-latexTruthTableMainColumnIndex s =
-  fst $ head $ filter (\(i, cell) -> isMain cell) $ zip [0..] $ serializeCells Latex s
-
-serializeLatexTruthTableRow :: [(String, Bool)] -> Statement -> Maybe [String]
-serializeLatexTruthTableRow ass s = map fromCellLatex <$> latexRow Main ass s
-  where
-    latexRow mkCell ass (Atom key)      = list <$> mkCell <$> toInt <$> eval ass (Atom key)
-    latexRow mkCell ass (Not s)         = (list <$> mkCell <$> toInt <$> not <$> eval ass s) <> latexRow NotMain ass s
-    latexRow mkCell ass (And s1 s2)     = latexRowBinaryConnective (&&) mkCell ass s1 s2
-    latexRow mkCell ass (Or s1 s2)      = latexRowBinaryConnective (||) mkCell ass s1 s2
-    latexRow mkCell ass (Implies s1 s2) = latexRowBinaryConnective implies mkCell ass s1 s2
-    latexRow mkCell ass (Iff s1 s2)     = latexRowBinaryConnective (==) mkCell ass s1 s2
-
-    latexRowBinaryConnective op mkCell ass s1 s2 =
-      (
-        \subrow1 subrow2 result ->
-          [NotMain " "] ++ subrow1 ++ [mkCell $ toInt result] ++ subrow2 ++ [NotMain " "]
-      ) <$>
-      latexRow NotMain ass s1 <*> latexRow NotMain ass s2 <*>
-      (op <$> eval ass s1 <*> eval ass s2)
-
-    toInt :: Bool -> String
-    toInt False = "0"
-    toInt True = "1"
-
-    list :: a -> [a]
-    list x = [x]
-
-    implies :: Bool -> Bool -> Bool
-    implies b1 b2 = not b1 || b2
-
-truthtable :: Statement -> String
-truthtable s = open <> header <> "\\hline\n" <> body <> close
-  where
-    mainIndex = latexTruthTableMainColumnIndex s
-
-    cellsSpec
-      | mainIndex == 0 && length serial <= 1 = "c"
-      | mainIndex == 0 = "c|" <> replicate (length serial - 1) 'c'
-      | mainIndex == length serial - 1 = replicate (length serial - 1) 'c' <> "|c"
-      | otherwise = replicate mainIndex 'c' <> "|c|" <> replicate (length serial - mainIndex - 1) 'c'
-
-    open =
-      "\\begin{tabular}{" <>
-      replicate (length atomsList) 'c' <>
-      "||" <>
-      cellsSpec <>
-      "}\n"
-
-    close = "\\end{tabular}\n\n"
-
-    serial :: [Cell]
-    serial = serializeCells Latex s
-
-    atomsList :: [String]
-    atomsList = S.toAscList $ atoms s
-
-    header :: String
-    header =
-      intercalate " & " (map dollars atomsList) <>
-      " & " <>
-      intercalate " & " (map dollars $ map fromCell serial) <>
-      " \\\\\n"
-
-    dollars :: String -> String
-    dollars string = "$" <> string <> "$"
-
-    body :: String
-    body = concat $ map line $ enumerate atomsList
-
-    line assignments =
-      intercalate " & " (bools assignments) <>
-      " &" <>
-      intercalate "&" (cells assignments) <>
-      "\\\\\n"
-
-    bools assignments = [if bool then "1" else "0" | (key, bool) <- assignments]
-
-    cells assignments =
-      (\xs -> [if x /= " " then " " <> x <> " " else " " | x <- xs]) $
-      fromJust $ serializeLatexTruthTableRow assignments s
+    fail err@(ParseError pos message) =
+      putStrLn $
+        "parse error at position "
+        <> show pos
+        <> ": "
+        <> message
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..47f8988
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,7 @@
+main: dirty clean
+
+dirty:
+	ghc Main.hs -o logic
+
+clean:
+	find | grep -E '\.(hi|o)' | xargs rm --