Threads of Interaction

Since the behaviour of an AgentRole depends on the incoming message and different communicative acts are allowed as an answer to a communicative act, the thread of interaction, that is, the processing of incoming messages, has to be split up into different threads of interaction. The lifeline of an AgentRole is split and the thread of interaction defines the reaction to received messages.
A thread of interaction is shown as a tall thin rectangle whose top is aligned with its initiation time and whose bottom is aligned with its completion time. It is drawn over the lifeline of an AgentRole.
The following two representations are equivalent.