import { set } from "https://deno.land/x/fun@v.2.0.0-alpha.11/mod.ts";
const { elemOf } = set;
Given an instance of Eq create a function that uakes a ReadonlySet and returns a predicate over a value A the returns true if the value is a member of the set. This is like elem but with the set and value parameters swapped.
Parameters
S: Eq<A>