- Origin
Conjoin and
- Constraint
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- Synonyms
,
,
,
,
.
- Arguments
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- Restrictions
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- Purpose
The variables of the collection correspond to the
variables of the collection according to a permutation.
In addition, each value (with )
should be taken by exactly variables of
the collection. Finally, each variable of
should be assigned a value of (with ).
- Example
-
The constraint holds since:
The values 1, 9, 1, 5, 2, 1 assigned to
correspond to a permutation of the values 9, 1, 1, 1, 2, 5
assigned to .
The values 1, 2, 5, 7 and 6 are respectively used
3, 1, 1, 0 and 1 times.
- Typical
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- Symmetries
Arguments are permutable w.r.t. permutation .
Items of are permutable.
Items of are permutable.
Items of are permutable.
An occurrence of a value of or that does not belong to can be replaced by any other value that also does not belong to .
All occurrences of two distinct values in , or can be swapped; all occurrences of a value in , or can be renamed to any unused value.
- Arg. properties
Contractible wrt. .
- Usage
See the
constraint.
- Algorithm
The filtering algorithm presented inΒ [BeldiceanuKatrielThiel05b]
can be reused for pruning the variables of the and the
collection. This algorithm does not restrict the
variables of the collection.
- See also
implies:
,
.
related:
Β (two overlapping plus restriction on values).
specialisation:
Β ( replaced by ).
- Keywords
application area:
assignment.
combinatorial object:
permutation,
multiset.
constraint arguments:
constraint between two collections of variables.
constraint type:
value constraint.
filtering:
flow.
modelling:
equality between multisets.
problems:
demand profile.