## 1. Definition

- Let be the n-th renewal
- Then = time of the last renewal (prior to time t)
- Let
- is called the age of the renewal process
- Interpretation: A(t) is the time since last renewal

- Let be the n-th renewal
- Then = time of the last renewal (prior to time t)
- Let
- is called the age of the renewal process
- Interpretation: A(t) is the time since last renewal