diff --git a/egison.cabal b/egison.cabal
--- a/egison.cabal
+++ b/egison.cabal
@@ -1,5 +1,5 @@
 Name:                egison
-Version:             2.3.5
+Version:             2.3.6
 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/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
@@ -354,6 +354,7 @@
 
 expandLoop :: Env -> Object -> IOThrowsError Object
 expandLoop env (Loop loopVar indexVar rangeObjRef loopExpr tailExpr) = do
+  cRefEval1 rangeObjRef
   b <- isEmptyCollection rangeObjRef
   if b
     then cEval1 $ Closure env tailExpr
@@ -548,9 +549,9 @@
       mPpmRet <- helper pclss
       case mPpmRet of
         Nothing -> throwError $ Default "inductiveMatch: not matched any primitive clauses"
-        Just tgtObjRefs -> do
+        Just tgtObjRefss -> do
           typObjRefs <- tupleToObjRefs typObjRef
-          return (typObjRefs, patObjRefs, tgtObjRefs)
+          return (typObjRefs, patObjRefs, tgtObjRefss)
      where helper [] = return Nothing
            helper ((env, ppat, expr):pclss2) = do
              mPpmRet <- primitivePatternMatch ppat tgtObjRef
@@ -642,11 +643,13 @@
         else return Nothing
     _ -> return Nothing
 primitivePatternMatch PEmptyPat objRef = do
+  cRefEval1 objRef
   b <- isEmptyCollection objRef
   if b
     then return (Just [])
     else return Nothing
 primitivePatternMatch (PConsPat carPat cdrPat) objRef = do
+  cRefEval1 objRef
   b <- isEmptyCollection objRef
   if b
     then return Nothing
@@ -659,6 +662,7 @@
                                     Nothing -> return Nothing
                                     Just cdrFrame -> return (Just (carFrame ++ cdrFrame))
 primitivePatternMatch (PSnocPat rdcPat racPat) objRef = do
+  cRefEval1 objRef
   b <- isEmptyCollectionForSnoc objRef
   if b
     then return Nothing
@@ -695,7 +699,7 @@
 
 isEmptyCollection :: ObjectRef -> IOThrowsError Bool
 isEmptyCollection objRef = do
-  obj <- cRefEval1 objRef
+  obj <- liftIO $ readIORef objRef
   case obj of
     Intermidiate (ICollection []) -> return True
     Intermidiate (ICollection ((IElement _):_)) -> return False
@@ -709,7 +713,7 @@
 
 isEmptyCollectionForSnoc :: ObjectRef -> IOThrowsError Bool
 isEmptyCollectionForSnoc objRef = do
-  obj <- cRefEval1 objRef
+  obj <- liftIO $ readIORef objRef
   case obj of
     Intermidiate (ICollection innerRefs) -> do
       case reverse innerRefs of
@@ -725,7 +729,7 @@
 
 consDestruct :: ObjectRef -> IOThrowsError (ObjectRef, ObjectRef)
 consDestruct objRef = do
-  obj <- cRefEval1 objRef
+  obj <- liftIO $ readIORef objRef
   case obj of
     Intermidiate (ICollection []) -> throwError $ Default "consDestructInnerRefs: empty collection"
     Intermidiate (ICollection ((IElement carObjRef):rest)) -> do
@@ -743,7 +747,7 @@
 
 snocDestruct :: ObjectRef -> IOThrowsError (ObjectRef, ObjectRef)
 snocDestruct objRef = do
-  obj <- cRefEval1 objRef
+  obj <- liftIO $ readIORef objRef
   case obj of
     Intermidiate (ICollection innerRefs) -> do
       case reverse innerRefs of