i
n
i
t
i
a
l
c
o
n
d
i
t
i
o
n
s
x
1
(
0
)
1
x
2
(
0
)
-
2
x
3
(
0
)
1
d
x
1
(
t
)
d
t
d
x
2
(
t
)
d
t
d
x
3
(
t
)
d
t
=
0
-
1
2
2
-
3
2
3
-
3
1
x
1
(
t
)
x
2
(
t
)
x
3
(
t
)
,
x
1
(
0
)
x
2
(
0
)
x
3
(
0
)
=
1
-
2
1
x
1
(
t
)
x
2
(
t
)
x
3
(
t
)
=
-
3
-
1
0
1
-
2
t
+
-
6
1
1
0
-
t
+
4
1
1
1
t