Method ADT.Relation.Binary()->`+()

Method `+
Method `|

ADT.Relation.Binary(< LeftType, RightType >) res = ADT.Relation.Binary() + rel
ADT.Relation.Binary(< LeftType, RightType >) res = ADT.Relation.Binary() | rel

Description

The expressions rel1 | rel2 and rel1 + rel2 return a new relation which has all the relation entries present in rel1, or rel2, or both.