...and the full text PDF can be downloaded for free until June 30:
To help support our community working remotely during COVID-19, we are making all work published by ACM in our Digital Library freely accessible through June 30, 2020

Enjoy!
Steve

On 13 Jun 2020 21:50, Vanessa Freudenberg <vanessa@codefrau.net> wrote:
Dan Ingalls� HOPL IV paper is out now:

https://dl.acm.org/doi/abs/10.1145/3386335

- Vanessa -