10 UMLUseCase 420 80 60 60 Bob UMLUseCase 70 80 60 60 Charlie UMLUseCase 240 80 60 60 Alice Relation 290 90 150 40 lt=<- $20 10.0;20.0;130.0;20.0 Relation 120 90 140 40 lt=<- $10 120.0;20.0;10.0;20.0