 To a first approximation, a hypercomputer is a system that yields the values of a function that is not Turing-computable. If what counts as yielding the values of a function is left unspecified, any of the systems discussed in Section 4.1, such as genuinely random processes and systems that manipulate arbitrary real-valued quantities, would count as hypercomputers. But in discussing Bold Physical CTT, we saw that yielding the values of a function that is Turing-uncomputable, without further constraints, is not enough for genuine physical computation.