I love it when APL threads pop up here - really a novel approach to making computers do useful things. The videos from 1975 demonstrating it seem decades ahead of their time. I'm surprised APL hasn't had more of a resurgence given the recent ascendancy of data science.

Thank you! I'm writing an APL-lineage language right now (really, APL+Prolog+Lustre "lineage") and hadn't come across this paper.

I found an HTML version here: https://www.jsoftware.com/papers/J1990.htm

canonical, nicely formatted and htmlized, version of this paper is https://www.jsoftware.com/papers/J1990.htm, and as should be obvious from url it is simply the first public release of j language; compare language summary with the current vocabulary https://code.jsoftware.com/wiki/NuVoc

Add `?download=true` to the link to view the PDF in your own reader software. (Although that probably doesn't bypass the Cloudflare check.)