I think it took me four tries before I finally read it all the way through. Eventually the text on formal systems becomes quite heavy and that's where I stopped

I think it took me four tries before I finally read it all the way through. Eventually the text on formal systems becomes quite heavy and that's where I stopped in my previous tries... once I got past that hump it was downhill all the way. Highly worth the effort; one of the best books I've ever read.