I read it putting all of myself into it (even caught a couple of typos/bugs). I also read Iverson's. These languages (APL, J, K) promote a programming paradigm

I read it putting all of myself into it (even caught a couple of typos/bugs). I also read Iverson's. These languages (APL, J, K) promote a programming paradigm that sits somewhere in between the continuous spectrum between imperative and functional paradigms. There is lot of good to absorb from J, and not little of it has fortunately permeated into the famous Python's numpy library. Many people have been inadvertently using APL/J deepest concepts thanks to it. I do think that, even if they are beautiful, they are still generations away from a community Zeitgeist that would render as widely spread as, for example, Haskell.