Generic Variables: simple implicity context passing

Hello everyone I have an idea for a new language feature to solve the problem of types that depend on runtime context to be meaningful. I also made a post about this on Zulip [1], but it isn't getting much traction so I want to share the idea here as well to get more feedback, and check if there was something obvious (or subtle) that I missed. To avoid restating the problem and bloating this post, check out @tmandry excellent explainer on the issues that arrise when using types that depend on ...