We've been using the word "binding" in our more formal work (see the specification repo, which is more up-to-date than the README), and having clarified that fo

We've been using the word "binding" in our more formal work (see the specification repo, which is more up-to-date than the README), and having clarified that for ourselves, we will probably stop talking about "immutable variables." A constant is declared with "let" and a non-constant is declared with "var", like in Swift. HTH