Oops, sorry for the slow reply - I'm not subscribed to this mailing list. As Mehdi2277 says, this would indeed require the Map operator we'll introduce in a future PEP. But that's a good point about the `*Tuple[int, Ts]` syntax. I think the interpretation of it that would be most consistent with the rest of PEP 646 would actually be something slightly different than you had in mind - instead of saying that the Callable took args like Tuple[int, Ts[0]], Tuple[int, Ts[1]], ... it would say that the Callable took a variable number of arguments, the first of which was `int`, and the rest of which are bound to `Ts`. And this is indeed something we haven't talked about explicitly how to specify yet. Most of the discussion of PEP 646 has taken place on typing-sig, so I'll start a new thread there to discuss this.