I came across this based on discussion threads here on APL. But even though it is old, it is still quite interesting in spite you may have to "learn" a bit APL

I came across this based on discussion threads here on APL. But even though it is old, it is still quite interesting in spite you may have to "learn" a bit APL in the process (or you may try to ignore but feel through it). The question is no doubt importance of the symbol in understanding and master a subject. <x| |x> etc. both hinder initially but ultimately help to understand certain physics. I think computer language definitely like that as well. (And if one of the commentator is right, it is also sad he sort of abandon it. But as a reader, I cannot say this interpretation one way or the other. I just like the paper and I think it has a lasting value. If one has to argue the hurdle of APL symbols are there. I wonder whether one can just use matrix ... or mathematical symbols ... but that is going to a debate which I do not want to. Just appreciate.)