Analyzing and Securing Social Networks

428 Analyzing and Securing Social Networks

subset of the result set of AT

1

. A conict will therefore occur if an agent possessing AT

1

is later

assigned AT

2

. When this occurs, AT

1

is discarded from the agent’s AT list to resolve the conict.

Subtype conicts occur when the ATTs in AT

2

involve data types that are subtypes of those in

AT

1

. The data types can be those of subjects, objects, or both.

Conict resolution is summarized by Algorithm 32.1. Here, Subset(AT

1

, AT

2

) is a func-

tion that returns true if the result set of AT

1

is a proper subset of the result set of AT

2

, and

SubjectSubType(AT

1

, AT

2

) returns true if the subject of AT

1

is a subtype of the subject of AT

2

.

Similarly, ObjectSubType(AT

1

, AT

2

) decides subtyping relations for objects i ...