Specifying the 'and' operator in event expressions
The and operator specifies an event pattern that might occur in any temporal order. It evaluates two event templates (or nested event expressions) simultaneously but only returns true when they are both true.
on A() and B() executeAction();
This will seek ‘an A followed by a B’ or ‘a B followed by an A’. Both are valid matching patterns, and the event listener will seek both concurrently. However, the first to occur will terminate all monitoring and cause the event listener to trigger.