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Short Description

A colleague is one of two or more (digital or non-digital) agents that have the same principal (on whose behalf they are executing an action).


Consider a traveler that uses her digital wallet to communicate her identity to an immigration officer. In order to decide whether or not to permit the traveler entrance to the country, it must establish that the traveler (as an actor that pushes the buttons of the digital wallet) and the digital wallet (i.e. the actor that communicates some identity data), work on behalf of one and the same party, i.e. the traveler (as a party).

Another example is a customer that uses a chat application (her agent) to contact the support department of her life insurance to sort something out. As the chat progresses, the life insurance agent must obtain some sensitive health-data, for which the chat channel isn't appropriate. He requests the customer to use another means (actor) that is capable of setting up a communications channel that is more secure so that she can use this other means as an agent to transmit her sensitive health data. In order to prevent health fraud, the life insurance agent must be capable of determining that both the other means are agents that share the same principal, i.e. the customer.


The ability to distinguish between (non) colleagues allows us to reason and communicate about the set of (digital and non-digital) actors that are agents for a **principal|principal. This is relevant in situations where different agents execute actions in a single business transaction on behalf of the same principal