[R] lme and ordering of terms

[Christoph Scherber]

Dear R users,

When fitting a lme() object (from the nlme library), is it possible to 
test interactions *before* main effects? As I understand, R 
conventionally re-orders all terms such that highest-order interactions 
come last - but I´d like to know if it´s possible (and sensible) to 
change this ordering of terms.

I´ve tried the terms() command (from aov) but I don´t know if something 
similar exists for lme() objects.

Thanks a lot for your help!

Best wishes
Christoph