This, however, is a different story :)  Good catch, @novemberborn.  I agree we should specify that `thenable.then` must be called with with `thenable` as its `thisArg`.  Obviously, `thenable.then` may have previously been bound to something else, but assimilators should make the attempt :)

Maybe something along these lines? "Otherwise, call `thenable.then` with `thisArg` as `thenable`, first argument as `resolvePromise`, and second argument as `rejectPromise`, where:"