I
n
[
]
:
=
2
x
-
2
x
2
2
w
x
-
2
x
2
2
w
x
O
u
t
[
]
=
2
π
-
-
2
x
2
2
w
2
w
x
+
π
2
3
w
E
r
f
x
2
w
w
E
r
f
x
2
w