Note Let denote the time from until thefirst event occurs, then we have, i.e., .
Thus we have
We are already aware that , which denotes that in the time interval the event occurs number of times. Thus diagrammatically it is as follows which is illustrated in Figure 2.5.
Figure 2.5 : The notational concept of time , and the number of events within each time intervals (which is denoted using colour scheme for ease of understanding)
denote the time from 
until the
, which denotes that in the time interval 
the event occurs 
number of times. Thus diagrammatically it is as follows which is illustrated in Figure 2.5.
