ANOVA with two random factors

Hi.

I have been learning R in order to use it for a class in design of
experiments.

I have been using the command lme() to reproduce results from Montgomery's
book "Design and Analysis of experiments".

I have a quantitative response variable called capacity, and two random
treatment factors: operator and part (already declared as factors in R).

I have been trying to estimate this model with the command:



lme(capacity~1,random=~1| (part*operator))

This worked for the analysis with just one random factor, but now it?s not
working.  Could anyone tell me how would be the correct syntax?  I would
highly appreciate it.


Gilbert Brenes