diff --git a/t/Makefile.am b/t/Makefile.am
index f3ac5bc..602f20c 100644
--- a/t/Makefile.am
+++ b/t/Makefile.am
@@ -16,14 +16,6 @@ check_ERRORS = \
 	do-5001.err \
 	do-5002.err \
 	feed-5001.err \
-	feed-5002.err \
-	feed-5003.err \
-	feed-5004.err \
-	feed-5005.err \
-	feed-5006.err \
-	feed-5007.err \
-	feed-5008.err \
-	feed-5009.err \
 	mlist-5001.err \
 	var-5001.err \
 	var-5002.err \
diff --git a/t/Makefile.in b/t/Makefile.in
index 9145492..a1e844f 100644
--- a/t/Makefile.in
+++ b/t/Makefile.in
@@ -487,14 +487,6 @@ check_ERRORS = \
 	do-5001.err \
 	do-5002.err \
 	feed-5001.err \
-	feed-5002.err \
-	feed-5003.err \
-	feed-5004.err \
-	feed-5005.err \
-	feed-5006.err \
-	feed-5007.err \
-	feed-5008.err \
-	feed-5009.err \
 	mlist-5001.err \
 	var-5001.err \
 	var-5002.err \
diff --git a/t/err.sh b/t/err.sh
index 23b1a34..951d51c 100644
--- a/t/err.sh
+++ b/t/err.sh
@@ -3,22 +3,73 @@
 for i in $@; do :; done
 script="$i"
 
-expected_errinfo=$(grep -n -o -E "##ERROR: .+" "$script" 2>/dev/null)
-[ -z "$expected_errinfo" ] && {
-	echo "INVALID TESTER - $script contains no ERROR information"
-	exit 1
+run_partfile() {
+	l_cmd="";
+	l_nargs=$#
+
+	while [ $# -gt 3 ]
+	do
+		l_cmd="$l_cmd $1"
+		shift
+	done
+
+	l_script="$1"
+	shift ## skip the original script.
+	l_partno="$1"
+	shift ## partno
+
+	l_partfile="$1"
+	l_cmd="$l_cmd $l_partfile"
+
+	l_expected_errinfo=$(grep -n -o -E "##ERROR: .+" "$l_partfile" 2>/dev/null)
+	[ -z "$l_expected_errinfo" ] && {
+		echo "ERROR: INVALID TESTER - $l_script($l_partno) contains no ERROR information"
+		return 1
+	}
+
+	l_expected_errline=$(echo $l_expected_errinfo | cut -d: -f1)
+	l_xlen=$(echo $l_expected_errline | wc -c)
+	l_xlen=$(expr $l_xlen + 10)
+	l_expected_errmsg=$(echo $l_expected_errinfo | cut -c${l_xlen}-)
+	l_output=`$l_cmd 2>&1`
+	## the regular expression is not escaped properly. the error information must not
+	## include specifial regex characters to avoid problems.
+	echo "$l_output" | grep -E "ERROR:.+${l_partfile}\[${l_expected_errline},[[:digit:]]+\] ${l_expected_errmsg}" >/dev/null 2>&1 || {
+		echo "ERROR: error not raised - $l_script($l_partno) - $l_output"
+		return 1
+	}
+
+	echo "OK"
+	return 0
 }
 
-expected_errline=$(echo $expected_errinfo | cut -d: -f1)
-xlen=$(echo $expected_errline | wc -c)
-xlen=$(expr $xlen + 10)
-expected_errmsg=$(echo $expected_errinfo | cut -c${xlen}-)
 
-output=$($@ 2>&1) 
-## the regular expression is not escaped properly. the error information must not
-## include specifial regex characters to avoid problems.
-echo "$output" | grep -E "ERROR:.+${script}\[${expected_errline},[[:digit:]]+\] ${expected_errmsg}" || {
-	echo "$script - $output"
-	exit 1
+ever_failed=0
+partfile=`mktemp`
+partno=0
+partlines=0
+> "$partfile"
+
+## TODO: don't use  while read line..
+while IFS= read -r line
+do
+	if [ "$line" = "---" ]
+	then
+		[ $partlines -gt 0 ] && {
+			run_partfile "$@" "$partno" "$partfile" || ever_failed=1
+		}
+		partno=`expr $partno + 1`
+		partlines=0
+		> "$partfile"
+	else
+		echo "$line" >> "$partfile"
+		partlines=`expr $partlines + 1`
+	fi
+done < "$script"
+
+[ $partlines -gt 0 ] && {
+	run_partfile "$@" "$partno" "$partfile" || ever_failed=1
 }
-exit 0
+
+rm -f "$partfile"
+exit $ever_failed
diff --git a/t/feed-5001.err b/t/feed-5001.err
index b8c4a56..071df03 100644
--- a/t/feed-5001.err
+++ b/t/feed-5001.err
@@ -1,2 +1,69 @@
 ## you can't have another colon before the method..
 (obj: :method) ##ERROR: syntax error - : disallowed
+
+---
+
+## while EOL is ignored in explicitly parenthesized XLIST, a semicolon must not be.
+(printf
+	"hello, world\n"
+)
+
+(printf; ##ERROR: syntax error - unexpected semicolon
+	"hello, world\n"
+)
+
+---
+
+## semicolon inside #{} must raise a syntax error
+
+a := #{
+	"k1":
+	"hello k1\n",
+	"k2":
+	"hello k2\n";   ##ERROR: syntax error - unexpected semicolon
+};
+
+---
+
+{
+	;;;
+
+(do
+	(printf "hello\n")
+	(printf "hello\n")
+);;
+
+k := [10 ; 20 ]; ##ERROR: syntax error - unexpected semicolon
+
+}
+
+---
+
+## a code point greater than 255 is illegal in the character literal prefix fixed with b.
+
+printf "[%c] [#x%x] [%d]\n" '★' '★' #x2605;
+printf "[%c]\n" b'★';  ##ERROR: syntax error - wrong character literal
+
+---
+
+## #b can be followed by [ or binary digits.
+
+printf "%O\n" #b[ 10 20 30 ];
+printf "%010b\n" #b0101;
+printf "%O\n" #bxy; ##ERROR: syntax error - neither valid radixed number nor valid directive #bxy
+
+---
+
+printf :*; ##ERROR: syntax error - prohibited in this context
+
+---
+
+defun :: fun1() { ##ERROR: syntax error - function name not symbol in defun
+	return 10;
+};
+
+---
+
+defun :* fun1() { ##ERROR: syntax error - function name not symbol in defun
+	return 10;
+};
diff --git a/t/feed-5002.err b/t/feed-5002.err
deleted file mode 100644
index 20f5ca7..0000000
--- a/t/feed-5002.err
+++ /dev/null
@@ -1,8 +0,0 @@
-## while EOL is ignored in explicitly parenthesized XLIST, a semicolon must not be.
-(printf
-	"hello, world\n"
-)
-
-(printf; ##ERROR: syntax error - unexpected semicolon
-	"hello, world\n"
-)
diff --git a/t/feed-5003.err b/t/feed-5003.err
deleted file mode 100644
index b80eaf3..0000000
--- a/t/feed-5003.err
+++ /dev/null
@@ -1,9 +0,0 @@
-## semicolon inside #{} must raise a syntax error
-
-a := #{
-	"k1":
-	"hello k1\n",
-	"k2":
-	"hello k2\n";   ##ERROR: syntax error - unexpected semicolon
-};
-
diff --git a/t/feed-5004.err b/t/feed-5004.err
deleted file mode 100644
index 348825b..0000000
--- a/t/feed-5004.err
+++ /dev/null
@@ -1,11 +0,0 @@
-{
-	;;;
-
-(do
-	(printf "hello\n")
-	(printf "hello\n")
-);;
-
-k := [10 ; 20 ]; ##ERROR: syntax error - unexpected semicolon
-
-}
diff --git a/t/feed-5005.err b/t/feed-5005.err
deleted file mode 100644
index 85ec90f..0000000
--- a/t/feed-5005.err
+++ /dev/null
@@ -1,4 +0,0 @@
-## a code point greater than 255 is illegal in the character literal prefix fixed with b.
-
-printf "[%c] [#x%x] [%d]\n" '★' '★' #x2605;
-printf "[%c]\n" b'★';  ##ERROR: syntax error - wrong character literal
diff --git a/t/feed-5006.err b/t/feed-5006.err
deleted file mode 100644
index e173b86..0000000
--- a/t/feed-5006.err
+++ /dev/null
@@ -1,6 +0,0 @@
-## #b can be followed by [ or binary digits.
-
-printf "%O\n" #b[ 10 20 30 ];
-printf "%010b\n" #b0101;
-printf "%O\n" #bxy; ##ERROR: syntax error - neither valid radixed number nor valid directive #bxy
-
diff --git a/t/feed-5007.err b/t/feed-5007.err
deleted file mode 100644
index 7d5dfe6..0000000
--- a/t/feed-5007.err
+++ /dev/null
@@ -1 +0,0 @@
-printf :*; ##ERROR: syntax error - prohibited in this context
diff --git a/t/feed-5008.err b/t/feed-5008.err
deleted file mode 100644
index 7070959..0000000
--- a/t/feed-5008.err
+++ /dev/null
@@ -1,3 +0,0 @@
-defun :: fun1() { ##ERROR: syntax error - function name not symbol in defun
-	return 10;
-};
diff --git a/t/feed-5009.err b/t/feed-5009.err
deleted file mode 100644
index b745f7e..0000000
--- a/t/feed-5009.err
+++ /dev/null
@@ -1,3 +0,0 @@
-defun :* fun1() { ##ERROR: syntax error - function name not symbol in defun
-	return 10;
-};
diff --git a/t/insta-02.hcl b/t/insta-02.hcl
index e25b362..f2a0594 100644
--- a/t/insta-02.hcl
+++ b/t/insta-02.hcl
@@ -1,6 +1,6 @@
 set t (
 	class | x | {
-		defun :* make() { set x 1234; return self; };
+		defun :* make() { x := 1234; return self; };
 		defun get-x() { return x };
 	}
 );
@@ -16,11 +16,11 @@ if (nqv? t 1234) { printf "ERROR: t must be 1234\n" } \
 else { printf "OK: t is %d\n" t };
 
 
-set j #{ ((X:make):get-x): 9999, 4512: ((X: make): get-x) };
-set v (dic.get j 1234);
+j := #{ ((X:make):get-x): 9999, 4512: ((X: make): get-x) };
+v := (dic.get j 1234);
 if (nqv? v 9999) { printf "ERROR: v is not 9999\n" } \
 else {  printf "OK:  value is %d\n" v };
 
-set v (dic.get j 4512);
+v := (dic.get j 4512);
 if (nqv? v 1234) { printf "ERROR: v is not 1234\n" } \
 else { printf "OK:  value is %d\n" v };