@startuml
autonumber

participant b as "Buyer"

box Seller TMF646, Appointment
participant sts as "Search Time Slot"
participant a as "Appointment"

alt rejecting the SearchTimeslot
  sts -> b: SearchTimeslotStateChangeEvent(rejected)
else rejecting the Appointment
  a -> b: AppointmentStateChangeEvent(cancelled)
end
@enduml