Piggybacking on my semi-serious remark above, if you do (i and j are indices, and f is a function or expression): for i j.f in Dex, this would be: i j $

Piggybacking on my semi-serious remark above, if you do (i and j are indices, and f is a function or expression): for i j.f in Dex, this would be: i j $ f in J. I think...