^^Relazione binaria tra 2 insiemi; in un insieme.
- Relazione binaria tra 2 insiemi X e Y
- un insieme di coppie ordinate (x,y) x∈X y∈Y
un sottoinsieme del prodotto cartesiano XxY
- Relazione binaria in/su un insieme X
- un insieme di coppie ordinate (x,y) x,y∈X
un sottoinsieme del prodotto cartesiano XxX
Binary relation over a set X ≡ Homogeneous relation ≡
endorelation
Es
the relation of kinship, where
the relation is over people.
Teo: A relation over a set may be identified with a directed graph
a relation XRX is identified with the directed graph where
- X is the vertex set
- R is the edge set
- there is an edge from a vertex x to a vertex y if and only if xRy
It is called the adjacency relation of the graph.
If the relation is symmetric, with an undirected graph.