diff --git a/bin/main.c b/bin/main.c
index 8a6dbe5..aae35fd 100644
--- a/bin/main.c
+++ b/bin/main.c
@@ -582,7 +582,8 @@ oops:
 	return -1;
 }
 
-#define DEFAULT_HEAPSIZE 512000ul
+//#define DEFAULT_HEAPSIZE (512000ul)
+#define DEFAULT_HEAPSIZE (0ul) /* don't use the pre-allocated heap */
 
 int main (int argc, char* argv[])
 {
diff --git a/lib/read.c b/lib/read.c
index 92620a6..1bd0a75 100644
--- a/lib/read.c
+++ b/lib/read.c
@@ -1042,6 +1042,38 @@ static HCL_INLINE int is_at_block_beginning (hcl_t* hcl)
 	return !rstl || (LIST_FLAG_GET_CONCODE(rstl->flagv) == HCL_CONCODE_BLOCK && (hcl->c->feed.rd.flagv & AT_BEGINNING));
 }
 
+static int forge_auto_xlist_if_at_block_beginning (hcl_t* hcl, hcl_frd_t* frd)
+{
+	if (is_at_block_beginning(hcl))
+	{
+		int forged_flagv;
+
+		/* both MLIST and ALIST begin as XLIST and get converted to MLIST 
+		 * or ALIST after more tokens are processed. so handling of MLIST
+		 * or ALIST is needed at this phase */
+		forged_flagv = AUTO_FORGED;
+		LIST_FLAG_SET_CONCODE (forged_flagv, HCL_CONCODE_XLIST);
+
+		/* this portion is similar to the code below the start_list label */
+		if (frd->level >= HCL_TYPE_MAX(int)) /* the nesting level too deep */
+		{
+			hcl_setsynerr (hcl, HCL_SYNERR_NESTING, TOKEN_LOC(hcl), TOKEN_NAME(hcl));
+			return -1;
+		}
+
+		/* since the actual list opener doesn't exist, the location of the
+		 * first element wil be the location of the list */
+		if (enter_list(hcl, TOKEN_LOC(hcl), forged_flagv) <= -1) return -1;
+		frd->level++; /* level after the forged list has been added */
+		/* a new list has been created automatically. unlike normal list creation
+		 * by an explicit symbol such as a left parenthesis, a left brace, etc,
+		 * the first element opens up this new list. so the AT_BEGINNING bit is
+		 * turned off here */
+		frd->flagv &= ~AT_BEGINNING;
+	}
+
+	return 0;
+}
 static int feed_process_token (hcl_t* hcl)
 {
 	hcl_frd_t* frd = &hcl->c->feed.rd;
@@ -1139,26 +1171,36 @@ static int feed_process_token (hcl_t* hcl)
 			}
 
 		case HCL_TOK_LBRACK: /* [ */
+			/* [] is a data list. so let's treat it like other literal
+			 * expressions(e.g. 1, "abc"). when it's placed at the block beginning,
+			 * create the outer XLIST. */
+			if (forge_auto_xlist_if_at_block_beginning(hcl, frd) <= -1) goto oops;
+
 			frd->flagv = DATA_LIST;
 			LIST_FLAG_SET_CONCODE (frd->flagv, HCL_CONCODE_ARRAY);
 			goto start_list;
 
 		case HCL_TOK_BAPAREN: /* #[ */
+			if (forge_auto_xlist_if_at_block_beginning(hcl, frd) <= -1) goto oops;
+
 			frd->flagv = DATA_LIST;
 			LIST_FLAG_SET_CONCODE (frd->flagv, HCL_CONCODE_BYTEARRAY);
 			goto start_list;
 
 		case HCL_TOK_LBRACE: /* { */
+			/* this is a block opener itself. auto xlist forge at the block beginning */
 			frd->flagv = 0;
 			LIST_FLAG_SET_CONCODE (frd->flagv, HCL_CONCODE_BLOCK);
 			goto start_list;
 
 		case HCL_TOK_DLPAREN: /* #{ */
+			if (forge_auto_xlist_if_at_block_beginning(hcl, frd) <= -1) goto oops;
 			frd->flagv = DATA_LIST;
 			LIST_FLAG_SET_CONCODE (frd->flagv, HCL_CONCODE_DIC);
 			goto start_list;
 
 		case HCL_TOK_QLPAREN: /* #( */
+			if (forge_auto_xlist_if_at_block_beginning(hcl, frd) <= -1) goto oops;
 			frd->flagv = DATA_LIST;
 			LIST_FLAG_SET_CONCODE (frd->flagv, HCL_CONCODE_QLIST);
 			goto start_list;
@@ -1458,6 +1500,7 @@ static int feed_process_token (hcl_t* hcl)
 			goto auto_xlist;
 
 		auto_xlist:
+			#if 0
 			if (is_at_block_beginning(hcl))
 			{
 				int forged_flagv;
@@ -1485,6 +1528,9 @@ static int feed_process_token (hcl_t* hcl)
 				 * turned off here */
 				frd->flagv &= ~AT_BEGINNING;
 			}
+			#else
+			if (forge_auto_xlist_if_at_block_beginning(hcl, frd) <= -1) goto oops;
+			#endif
 			break;
 	}
 
diff --git a/t/Makefile.am b/t/Makefile.am
index d9880a5..a54c962 100644
--- a/t/Makefile.am
+++ b/t/Makefile.am
@@ -6,9 +6,11 @@ check_SCRIPTS = \
 	insta-02.hcl \
 	ret-01.hcl \
 	retvar-01.hcl \
-	va-01.hcl
+	va-01.hcl \
+	var-02.hcl
 
 check_ERRORS = \
+	call-01.err \
 	class-01.err \
 	do-01.err \
 	do-02.err \
diff --git a/t/Makefile.in b/t/Makefile.in
index 5f6751b..65355a9 100644
--- a/t/Makefile.in
+++ b/t/Makefile.in
@@ -477,9 +477,11 @@ check_SCRIPTS = \
 	insta-02.hcl \
 	ret-01.hcl \
 	retvar-01.hcl \
-	va-01.hcl
+	va-01.hcl \
+	var-01.hcl
 
 check_ERRORS = \
+	call-01.err \
 	class-01.err \
 	do-01.err \
 	do-02.err \
diff --git a/t/call-01.err b/t/call-01.err
new file mode 100644
index 0000000..c8a996d
--- /dev/null
+++ b/t/call-01.err
@@ -0,0 +1,3 @@
+## the expression begins with a dictionary expression. 
+## it is not a function name and can'be be invoked.
+#{100:1, 200: 3}; ##ERROR: syntax error - invalid callable
diff --git a/t/var-02.hcl b/t/var-02.hcl
new file mode 100644
index 0000000..64977a1
--- /dev/null
+++ b/t/var-02.hcl
@@ -0,0 +1,24 @@
+defun x (a ::: x y z) {
+	x := (* a a);
+	y := (+ a a);
+	z := (- x y);
+};
+
+j := 21;
+
+if (eqv? j 20) {
+	[a,b,c] := (x 20);
+	q := (x 20);
+} else {
+	[a,b,c] := (x 30);
+	q := (x 30);
+};
+
+if (/= a 900) { print "ERROR: a is not 900\n" }
+else { printf "OK: %d\n" a };
+
+if (/= b 60) { print "ERROR: b is not 60\n" }
+else { printf "OK: %d\n" b };
+
+if (/= c 840) { print "ERROR: c is not 840\n" }
+else { printf "OK: %d\n" c };