It turned out that it wasn't exactly urgent to get the revised version of my Intro to Formal Logic off to CUP when I got back from Italy. So I put it to one side to take another look at when I was less busy. I'm now working though it again. Which is just about proving worth doing, as I'm still finding little ways of clarifying a sentence here, sharpening a point there. It's all a bit time consuming though. So this must be the last revision, and I will then force myself to let it go.