<instance>
<presentation name="Queens" nbSolutions="at least 1" format="XCSP 2.1">
This is the 4-queens instance represented in intention.

</presentation>
<domains nbDomains="1">
<domain name="D0" nbValues="4">
1..4
</domain>
</domains> <variables nbVariables="4">
<variable name="V0" domain="D0"/>
<variable name="V1" domain="D0"/>
<variable name="V2" domain="D0"/> <variable name="V3" domain="D0"/>
</variables>
<predicates nbPredicates="1">
<predicate name="P0">
<parameters> int X0 int X1 int X2 </parameters> <expression>
<functional> and(ne(X0,X1),ne(abs(sub(X0,X1)),X2)) </functional>
</expression>
</predicate>
</predicates>
<constraints nbConstraints="6">
<constraint name="C0" arity="2" scope="V0 V1" reference="P0">
<parameters> V0 V1 1 </parameters>
</constraint>
<constraint name="C1" arity="2" scope="V0 V2" reference="P0">
<parameters> V0 V2 2 </parameters>
</constraint>
<constraint name="C2" arity="2" scope="V0 V3" reference="P0">
<parameters> V0 V3 2 </parameters>
</constraint>
<constraint name="C3" arity="2" scope="V1 V2" reference="P0">
<parameters> V1 V2 1 </parameters>
</constraint>
<constraint name="C4" arity="2" scope="V1 V3" reference="P0">
<parameters> V1 V3 2 </parameters>
</constraint> <constraint name="C5" arity="2" scope="V2 V3" reference="P0">
<parameters> V2 V3 1 </parameters>
</constraint>
</constraints>
</instance>
Figure 3: The *4-queens* instance in intention