The basic event unit of DEBL is the primitive event.
A Backus Normal Form (BNF) definition of DEBL is provided in the appendix.
In order to adapt to an individual user's perception, DEBL supports a hierarchy of logical levels of events.
It may be specified in DEBL as *(from_host * from_sender * to_receiver).
Conceptually, every object we are dealing with in DEBL is an interval.
We mix temporal logic with DEBL to enhance the expressive power of DEBL to express certain important temporal properties like eventually and infinetely frequent which are impossible to express in other languages like EDL , ECSP  or TSL [L].
The aggregate event construct in DEBL is motivated by EDL  and has a similar structure.