Those things can in principle be expressed with a predicate using the SATISFIES type specifier, but the problem with that is that you currently can't pick such

Those things can in principle be expressed with a predicate using the SATISFIES type specifier, but the problem with that is that you currently can't pick such types apart for optimization purposes in any existing implementation, only test membership for values. Presumably that's one of the reasons why Qi/Shen was created.