## Nonstationary Poisson Processes

For a nonstationary/non-homogenous Poisson process, are the inter-arrival times (i) exponential, (ii) independent, or (iii) identically distributed?

Poisson process - Wikipedia, the free encyclopedia

I know that they are not i.i.d., but I do not know how to show this. Also, I'm not sure if I know if they are exponential.