On the complement of one complexity class in another
We investigate the diagonalization theorems in  (Theorem 23),  (Theorem 6) and  (main Theorem) and show that they can be strengthened so as to be applicable to most complexity classes, not just to those closed under polynomial-time reducibility. Thus the applications in ,  and  (e.g. P ≠ P ⇒ NP\P is not recursively presentable) are not peculiar to P, NP, PSPACE etc.; rather, they are examples of properties common to almost all "reasonable" complexity classes.
KeywordsTuring Machine Complexity Class Regular Language Finite Variation Polynomial Hierarchy
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