<s>
The	O
hidden	B-Application
transformation	I-Application
reformulates	O
a	O
constraint	B-Application
satisfaction	I-Application
problem	I-Application
in	O
such	O
a	O
way	O
all	O
constraints	O
have	O
at	O
most	O
two	O
variables	O
.	O
</s>
<s>
The	O
hidden	B-Application
transformation	I-Application
converts	O
an	O
arbitrary	O
constraint	B-Application
satisfaction	I-Application
problem	I-Application
into	O
a	O
binary	O
one	O
.	O
</s>
<s>
The	O
transformation	O
is	O
similar	O
to	O
that	O
generating	O
the	O
dual	B-Application
problem	I-Application
.	O
</s>
