Formalization of extensible unions in Elm
Unknown author. Declarative Rule System. Unknown year. Creative Commons Attribution-ShareAlike 3.0 Unported License (NOT a CC-BY 4.0 License).
August 31, 2020
This is a follow-up to my previous post https://shuangrimu.com/posts/elm-extensible-unions.html.
Since then there’s been a lot of interest in the associated Elm Discourse thread.
Evan asked for a more formal treatment than the previous post, so here I give one.
It involves a lot of math symbols so I’ve typed it up in LaTeX and made it a PDF. The link is here