[Gretl-users] Compute an integral

Dear all, I am using Grelt 1.8.7 with Ubuntu and I am mainly using it for teaching. With colleagues we are preparing tutorials. One of the tutorial estimate a weibull model with the mle block. We use censored data on unemployment. I have heard that there is a "duration" command but for teaching purposes we prefer to use the mle block. We are quite keen on making sure students understand the different contributions to the likelihood. On top of that we would like them to estimate the mean time passed in unemployment. The mean of a weibull distribution is not very easy to compute by hand. Again I know that $yhat save exactly this after a "duration" command but we are interested in doing it by hand. How do you compute an integral within gretl? I hope this message is clear enough, JB