diff --git a/egison.cabal b/egison.cabal
--- a/egison.cabal
+++ b/egison.cabal
@@ -1,5 +1,5 @@
 Name:                egison
-Version:             3.0.6
+Version:             3.0.7
 Synopsis:            An Interpreter for the Programming Language Egison
 Description:         An interpreter for the programming language Egison.
                      A feature of Egison is the strong pattern match facility.
diff --git a/hs-src/Interpreter/egisoni.hs b/hs-src/Interpreter/egisoni.hs
--- a/hs-src/Interpreter/egisoni.hs
+++ b/hs-src/Interpreter/egisoni.hs
@@ -114,6 +114,8 @@
             Left err | show err =~ "expecting (top-level|\"define\")" -> do
               result <- liftIO $ fromEgisonM (readExpr newInput) >>= either (return . Left) (evalEgisonExpr env)
               case result of
+                Left err | show err =~ "unexpected end of input" -> do
+                  loop env (take (length prompt) (repeat ' ')) $ newInput ++ "\n"
                 Left err -> do
                   liftIO $ putStrLn $ show err
                   loop env prompt ""
diff --git a/hs-src/Language/Egison/Core.hs b/hs-src/Language/Egison/Core.hs
--- a/hs-src/Language/Egison/Core.hs
+++ b/hs-src/Language/Egison/Core.hs
@@ -194,7 +194,8 @@
   generateArray env name size expr
 evalExpr env (GenerateArrayExpr (name:xs) (TupleExpr (size:ys)) expr) = 
   generateArray env name size (GenerateArrayExpr xs (TupleExpr ys) expr)
-evalExpr _ (GenerateArrayExpr _ _ _) = throwError $ strMsg "invalid generate-array expression"
+evalExpr env (GenerateArrayExpr names size expr) = 
+  evalExpr env (GenerateArrayExpr names (TupleExpr [size]) expr)
 
 evalExpr env (ArraySizeExpr expr) = 
   evalExpr env expr >>= arraySize
@@ -461,6 +462,8 @@
                   keys <- return $ IntMap.keys ary
                   vals <- mapM (newEvaluatedThunk . Value) $ IntMap.elems ary
                   return . Intermediate . IArray $ IntMap.insert index ref (IntMap.fromList $ zip keys vals)
+                updateArray _ _ = do
+                  throwError $ strMsg "expected array value"
                 subst :: (Eq a) => a -> b -> [(a, b)] -> [(a, b)]
                 subst k nv ((k', v'):xs) | k == k'   = (k', nv):(subst k nv xs)
                                          | otherwise = (k', v'):(subst k nv xs)
diff --git a/hs-src/Language/Egison/Desugar.hs b/hs-src/Language/Egison/Desugar.hs
--- a/hs-src/Language/Egison/Desugar.hs
+++ b/hs-src/Language/Egison/Desugar.hs
@@ -4,6 +4,8 @@
 import Control.Applicative ((<$>), (<*>), (<*), (*>), pure)
 import qualified Data.Sequence as Sq
 import Data.Sequence (ViewL(..), (<|))
+import qualified Data.Set as S
+import Data.Set (Set)
 import Data.Char (toUpper)
 import Control.Monad.Error
 import Control.Monad.State
@@ -54,7 +56,7 @@
         where
           genClauses :: [(String, [EgisonExpr])] -> DesugarM [MatchClause]
           genClauses patterns = (++) <$> mapM genClause patterns
-                                     <*> pure [(WildCard, matchingFailure)]
+                                     <*> pure [((TuplePat [WildCard, WildCard]), matchingFailure)]
           
           genClause :: (String, [EgisonExpr]) -> DesugarM MatchClause
           genClause pattern = do
@@ -185,22 +187,48 @@
 desugar expr = return expr
 
 desugarPattern :: EgisonPattern -> DesugarM EgisonPattern
-desugarPattern (ValuePat expr) = ValuePat <$> desugar expr
-desugarPattern (PredPat expr) = PredPat <$> desugar expr
-desugarPattern (CutPat pattern) = CutPat <$> desugarPattern pattern
-desugarPattern (NotPat pattern) = NotPat <$> desugarPattern pattern
-desugarPattern (AndPat patterns) = AndPat <$> mapM desugarPattern patterns
-desugarPattern (OrPat patterns)  = OrPat <$> mapM desugarPattern patterns
-desugarPattern (TuplePat patterns)  = TuplePat <$> mapM desugarPattern patterns
-desugarPattern (InductivePat name patterns) =
-  InductivePat name <$> mapM desugarPattern patterns
-desugarPattern (IndexedPat pattern exprs) =
-  IndexedPat <$> desugarPattern pattern <*> mapM desugar exprs
-desugarPattern (ApplyPat expr patterns) =
-  ApplyPat <$> desugar expr <*> mapM desugarPattern patterns 
-desugarPattern (LoopPat name expr pattern1 pattern2) =
-  LoopPat name <$> desugar expr <*> desugarPattern pattern1 <*> desugarPattern pattern2
-desugarPattern pattern = return pattern
+desugarPattern pattern = LetPat (map makeBinding $ S.elems $ collectName pattern) <$> desugarPattern' pattern 
+ where
+   collectNames :: [EgisonPattern] -> Set String
+   collectNames patterns = S.unions $ map collectName patterns
+
+   collectName :: EgisonPattern -> Set String
+   collectName (CutPat pattern) = collectName pattern 
+   collectName (NotPat pattern) = collectName pattern
+   collectName (AndPat patterns) = collectNames patterns
+   collectName (TuplePat patterns) = collectNames patterns
+   collectName (InductivePat _ patterns) = collectNames patterns
+   collectName (ApplyPat _ patterns) = collectNames patterns
+   collectName (LoopPat _ _ pattern1 pattern2) = collectName pattern1 `S.union` collectName pattern2
+   collectName (LetPat _ pattern) = collectName pattern
+   collectName (IndexedPat (PatVar name) _) = S.singleton name
+   collectName (OrPat patterns) = collectNames patterns
+   collectName _ = S.empty
+   
+   makeBinding :: String -> BindingExpr
+   makeBinding name = ([name], ArrayExpr [])
+
+desugarPattern' :: EgisonPattern -> DesugarM EgisonPattern
+desugarPattern' (ValuePat expr) = ValuePat <$> desugar expr
+desugarPattern' (PredPat expr) = PredPat <$> desugar expr
+desugarPattern' (CutPat pattern) = CutPat <$> desugarPattern' pattern
+desugarPattern' (NotPat pattern) = NotPat <$> desugarPattern' pattern
+desugarPattern' (AndPat patterns) = AndPat <$> mapM desugarPattern' patterns
+desugarPattern' (TuplePat patterns)  = TuplePat <$> mapM desugarPattern' patterns
+desugarPattern' (InductivePat name patterns) =
+  InductivePat name <$> mapM desugarPattern' patterns
+desugarPattern' (IndexedPat pattern exprs) =
+  IndexedPat <$> desugarPattern' pattern <*> mapM desugar exprs
+desugarPattern' (ApplyPat expr patterns) =
+  ApplyPat <$> desugar expr <*> mapM desugarPattern' patterns 
+desugarPattern' (LoopPat name expr pattern1 pattern2) =
+  LoopPat name <$> desugar expr <*> desugarPattern' pattern1 <*> desugarPattern' pattern2
+desugarPattern' (LetPat binds pattern) = do
+  LetPat <$> desugarBindings binds <*> desugarPattern' pattern
+desugarPattern' (OrPat patterns)  = 
+  OrPat <$> mapM desugarPattern' patterns
+desugarPattern' pattern = return pattern
+
 
 desugarBinding :: BindingExpr -> DesugarM BindingExpr
 desugarBinding (name, expr) = do
diff --git a/hs-src/Language/Egison/Parser.hs b/hs-src/Language/Egison/Parser.hs
--- a/hs-src/Language/Egison/Parser.hs
+++ b/hs-src/Language/Egison/Parser.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE TupleSections #-}
 module Language.Egison.Parser 
        ( readTopExprs
        , readTopExpr
@@ -121,7 +122,7 @@
              <|> try varExpr
              <|> inductiveDataExpr
              <|> try arrayExpr
-             <|> tupleExpr
+             <|> try tupleExpr
              <|> collectionExpr
              <|> parens (ifExpr
                          <|> lambdaExpr
@@ -237,7 +238,13 @@
 letExpr = keywordLet >> LetExpr <$> bindings <*> expr
 
 doExpr :: Parser EgisonExpr
-doExpr = keywordDo >> DoExpr <$> bindings <*> expr
+doExpr = keywordDo >> DoExpr <$> statements <*> expr
+
+statements :: Parser [BindingExpr]
+statements = braces $ sepEndBy statement whiteSpace
+
+statement :: Parser BindingExpr
+statement = try binding <|> brackets (([],) <$> expr)
 
 bindings :: Parser [BindingExpr]
 bindings = braces $ sepEndBy binding whiteSpace