// Interview collaboration

JOURNALIST = (shake_hands -> INTERVIEW),
INTERVIEW = (talk -> INTERVIEW | bye -> JOURNALIST).

SECRETARY = (comes -> TALK),
TALK = (talk_with_secretary -> TALK | goes -> SECRETARY).

||SYSTEM_1 = (JOURNALIST || SECRETARY).

DIRECTOR = (shake_hands -> INTERVIEW),
INTERVIEW = (talk -> INTERVIEW | bye -> DIRECTOR | comes -> TALK),
TALK = (talk_with_secretary -> TALK | goes -> INTERVIEW).

||SYSTEM_2 = (JOURNALIST || SECRETARY || DIRECTOR).