5.274. nequivalence
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- Origin
- Constraint
- Arguments
- Restrictions
- Purpose
is the number of distinct rests obtained by dividing the variables of the collection by .
- Example
-
Since the expressions , , , , , , and involve two distinct values (values 0 and 2), the first argument of the constraint is set to value 2.
- Typical
- Symmetries
Items of are permutable.
An occurrence of a value of can be replaced by any other value such that is congruent to modulo .
- Arg. properties
Functional dependency: determined by and .
Contractible wrt. when and .
Contractible wrt. when .
Extensible wrt. when .
- Algorithm
Since constraints and are similar, one should also use a similar algorithm as the one [Beldiceanu01], [BeldiceanuCarlssonThiel02] provided for constraint .
- See also
related: Β ( replaced by ), Β ( replaced by ), Β ( replaced by of ).
specialisation: Β ( replaced by ).
- Keywords
constraint arguments: pure functional dependency.
constraint type: counting constraint, value partitioning constraint.
final graph structure: strongly connected component, equivalence.
modelling: number of distinct equivalence classes, functional dependency.
- Arc input(s)
- Arc generator
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- Arc arity
- Arc constraint(s)
- Graph property(ies)
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- Graph model
PartsΒ (A) andΒ (B) of FigureΒ 5.274.1 respectively show the initial and final graph associated with the Example slot. Since we use the graph property we show the different strongly connected components of the final graph. Each strongly connected component corresponds to one equivalence class: We have two equivalence classes that respectively correspond to values and .
Figure 5.274.1. Initial and final graph of the constraint
(a) (b)