Suppose that the likelihood function (1.12) arises from a discrete failure time variable with sample space βι,… , α*. Assume also that censoring can occur only at these discrete times and that, as usual, a censored failure time t means that the underlying survival time exceeds /. Using the asymptotic likelihood methods of Section 3.4, derive the joint asymptotic distribution of the product limit estimators Compare the asymptotic variance of