5.287. nvalue_on_intersection
| DESCRIPTION | LINKS | GRAPH |
- Origin
- Constraint
- Arguments
- Restrictions
- Purpose
is the number of distinct values that both occur in the and collections.
- Example
-
Note that the two collections and share two values in common (i.e.,Β values 1 and 9). Consequently the constraint holds since its first argument is set to 2.
- Typical
- Symmetries
Arguments are permutable w.r.t. permutation .
Items of are permutable.
Items of are permutable.
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
Functional dependency: determined by and .
Contractible wrt. when .
Contractible wrt. when .
- See also
- Keywords
constraint arguments: pure functional dependency.
constraint type: counting constraint, constraint on the intersection.
final graph structure: connected component.
modelling: number of distinct values, 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 5.287.1 respectively show the initial and final graph associated with the Example slot. Since we use the graph property we show the connected components of the final graph. The variable is equal to this number of connected components. Note that all the vertices corresponding to the variables that take values 5, 2 or 6 were removed from the final graph since there is no arc for which the associated equality constraint holds.
Figure 5.287.1. Initial and final graph of the constraint
(a) (b)