It is very pleasant to see what must often have been a major complication largely removed. (My choice of words indicate that I have not chosen p and q for an ARMA (p, q) process very often. ) As a bystander, I have two sorts of comments to make: (1) how we can make the procedure proposed by Gray et al even more perspicuous (specifically in picking which column of R’s or S’s to examine, and (2) what il might he in order to do now