counting process
A stochastic process is called acounting process
if, for each outcome in the sample space ,
- 1.
for all ,
- 2.
is piecewise constant,
- 3.
is non-decreasing,
- 4.
is right continuous
(continuous from the right), and
- 5.
for any , there is an such that and .
Remark. For any , the random variable is usually called the number of occurrences of some event by time . Then, for , is the number of occurrences in the half-open interval.