Hi, I suppose I would say that (xRy) is both functional and inverse functional. :)
Marko. http://markorodriguez.com On Jul 12, 2011, at 12:36 PM, Niels Hoogeveen wrote: > > Thanks Marko, > That's not exactly what I am looking for. I'd like to know what the name is > of a relationship where there is only one unique combination of x and y in > xRy for every relationship type R. > Neo4j allows the creation of 2^64 relationships of the same type between the > same two nodes. I'd like to define a type where there can be only one > relationship of the same type between the same two nodes (eg. to limit the > number of "FRIEND" relations between two Persons, since it is no use being > friends with the same person multiple times, yet I'd like to allow a Person > to have multiple "WINNER" relationships to a certain game (the count of the > number of relationships indicating how often a person has been the winner of > that game)). > Is there any official name for a relationship type where the tuple (x, R, y) > must be unique? > Niels > >> From: [email protected] >> Date: Tue, 12 Jul 2011 10:27:04 -0600 >> To: [email protected] >> Subject: Re: [Neo4j] math question >> >> Hi, >> >> That is called a functional relationship. >> >> A functional relationship states that there is only one unique y in (xRy) >> for every x. >> - e.g. Social Security Number, Father, BornIn >> >> Inverse functional relationships are that there is a unique x in (xRy), for >> every y. >> >> See ya, >> Marko. >> >> http://markorodriguez.com >> >> On Jul 12, 2011, at 9:39 AM, Niels Hoogeveen wrote: >> >>> >>> Does anyone know the proper mathematical name for a relationship with the >>> following properties: >>> For all x in X and y in Y it holds that if xRy and xR'y then R = R'. >>> Example: >>> There can be only one IS_PARENT relation from one person to another. >>> Someone cannot be twice parent to the same person. >>> There can be several IS_PRESIDENT_OF relations from one person to an >>> organization. Someone can be president of an organizations from 1992-1997 >>> and again from 2004-2008. >>> Niels >>> _______________________________________________ >>> Neo4j mailing list >>> [email protected] >>> https://lists.neo4j.org/mailman/listinfo/user >> >> _______________________________________________ >> Neo4j mailing list >> [email protected] >> https://lists.neo4j.org/mailman/listinfo/user > > _______________________________________________ > Neo4j mailing list > [email protected] > https://lists.neo4j.org/mailman/listinfo/user _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
