In an agent or other software system, an {[event}} can trigger behaviour such as a method being executed or a message being sent. The term trigger is sometimes used as a noun to refer to the condition that gives rise to the action (e.g. "the trigger for turning on the hearing is when the temperature is below 5 degrees"") and sometimes as a verb for the invoking of the action (e.g. "the temperature drop triggered the hearting system to start").
Used on Chap. 6: page 117; Chap. 13: page 312; Chap. 14: page 318; Chap. 16: pages 370, 371, 372; Chap. 19: pages 458, 478, 481