I
n
[
]
:
=
(
*
F
i
n
d
z
f
o
r
f
i
x
e
d
v
a
l
u
e
s
o
f
x
a
n
d
y
;
f
o
r
e
x
a
m
p
l
e
(
x
=
0
,
y
=
0
)
*
)
f
u
n
1
=
f
u
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/
.
{
x
0
,
y
0
}
;
S
o
l
v
e
[
f
u
n
1
0
,
z
]