# Submissions:Symmetric n-ary relationship

(Difference between revisions)
 Revision as of 16:58, 1 September 2010 (view source)m ← Previous diff Revision as of 17:25, 1 September 2010 (view source)Next diff → Line 10: Line 10: }} }} {{Logical OP Description Template {{Logical OP Description Template - |Motivation=The symmetric n-ary relationship pattern emerged from the need of modelling distances among two points..This problem is a clear case of an n-ary relationship where the relation between two places needs a further argument to represent the distance. Once we have applied the n-ary pattern for this use case (http://www.w3.org/TR/swbp-n-aryRelations/#useCase1), we can realize that the origin and the destination of the n-ary relation belong to the same class. Moreover, the value for the relationship is the same to represent the distance from A to B and vice-versa. Then, if we want to represent both distances we should instanciate the pattern twice, from A to B and vice-versa, resulting in a redundant representation. + |Motivation=The symmetric n-ary relationship pattern emerged from the need of modelling distances among two points. - |Aim=This pattern allows representing symmetric n-ary relationships, i.e. binary relationships between two elements that need a further argument that has the same value for both directions of the relationship. If SNAry is the symmetric n-ary relationship and z is its value for the elements x and y, then: + This problem is a clear case of an n-ary relationship where the relation between two points needs a further argument to represent the distance between such points. + + Once we have applied the n-ary pattern for this use case (http://www.w3.org/TR/swbp-n-aryRelations/#useCase1), we can realize that the origin and the destination of the n-ary relation belong to the same class. In addition, the value for the relationship is the same to represent the distance from A to B and vice-versa. Then, if we want to represent both distances we should instanciate the pattern twice, from A to B and vice-versa, resulting in a redundant representation. + |Aim=This pattern allows representing symmetric n-ary relationships, i.e. binary relationships between two elements that need a further argument that has the same value for both directions of the relationship. + If SNAry is the symmetric n-ary relationship and z is its value for the elements x and y, then: SNAry(x,y)=z iff SNAry(y,x)=z SNAry(x,y)=z iff SNAry(y,x)=z - |Solution=Create a class to represent the n-ary relationship which will contain the value for the further needed argument (Relationship or Attribute). Create a relationship between this class and the classes involved in the symmetric n-ary relationship. + |Solution=A class to represent the n-ary relationship together with the value for the further needed argument (Relationship or Attribute) has been created. + A relationship between the abovementioned class and the classes involved in the symmetric n-ary relationship is created. |Elements=Class, Relationship, Attribute |Elements=Class, Relationship, Attribute Axioms: cardinality and equivalentClass Axioms: cardinality and equivalentClass Line 20: Line 25: |ProblemExample=For example, we might want to represent the distance expressed in kilometres between two places. |ProblemExample=For example, we might want to represent the distance expressed in kilometres between two places. |SolutionExample=http://ontologydesignpatterns.org/wiki/images/b/bd/Symmetric_n-ary_relationship_distance.jpg |SolutionExample=http://ontologydesignpatterns.org/wiki/images/b/bd/Symmetric_n-ary_relationship_distance.jpg - |Consequences=The main advantage of this pattern is that allows representing distance between places without being redundant. + |Consequences=The main advantage of this pattern is that allows representing distance between places without including redundancy in the ontology. }} }} {{Logical OP Reference Template {{Logical OP Reference Template

## Revision as of 17:25, 1 September 2010

 If you are a member of quality committee please visit the If you are author of this proposal or you want to contribute to this pattern's review, you can: In general, it could be useful to visit the evaluation section to have information about the evaluation process of this proposal Current revision ID: 9955

Diagram

# General information

 Name Symmetric n-ary relationship MariaPoveda, MariCarmenSuarezFigueroa MariaPoveda, MariCarmenSuarezFigueroa

# Description

 Motivation The symmetric n-ary relationship pattern emerged from the need of modelling distances among two points. This problem is a clear case of an n-ary relationship where the relation between two points needs a further argument to represent the distance between such points. Once we have applied the n-ary pattern for this use case (http://www.w3.org/TR/swbp-n-aryRelations/#useCase1), we can realize that the origin and the destination of the n-ary relation belong to the same class. In addition, the value for the relationship is the same to represent the distance from A to B and vice-versa. Then, if we want to represent both distances we should instanciate the pattern twice, from A to B and vice-versa, resulting in a redundant representation. This pattern allows representing symmetric n-ary relationships, i.e. binary relationships between two elements that need a further argument that has the same value for both directions of the relationship. If SNAry is the symmetric n-ary relationship and z is its value for the elements x and y, then: SNAry(x,y)=z iff SNAry(y,x)=z A class to represent the n-ary relationship together with the value for the further needed argument (Relationship or Attribute) has been created. A relationship between the abovementioned class and the classes involved in the symmetric n-ary relationship is created. Class, Relationship, Attribute Axioms: cardinality and equivalentClass

# Example

 Problem example For example, we might want to represent the distance expressed in kilometres between two places. http://ontologydesignpatterns.org/wiki/images/b/bd/Symmetric_n-ary_relationship_distance.jpg The main advantage of this pattern is that allows representing distance between places without including redundancy in the ontology.

# Pattern reference

 Origin Modelling distance between stages of St James Way during the Geobuddies ontology network development (http://geobuddies.dia.fi.upm.es). Geobuddies ontology network N-ary Relation: New Class (LP-NR -01)

# Scenarios

No scenario is added to this Content OP.

# Reviews

Review article Posted on About revision (current is 9955)
OlafNoppens about Symmetric n-ary relationship 245545616 September 2010 1006610,066
RimDJEDIDI about Symmetric n-ary relationship 245545616 September 2010 1010610,106

This revision (revision ID 9955) takes in account the reviews: none

Other info at evaluation tab

# Modeling issues

Modeling issues about Symmetric n-ary relationship

There is no Modeling issue related to this proposal.

# References

Submission to event