recursive properties of abstract complexity classes (preliminary version)
It is proven that complexity classes of abstract measures of complexity need not be recursively enumerable. However, the complement of each class is r.e. Properties of effective enumerations of complexity classes are studied. For any measure there is another measure with 'almost' the same complexity classes such that almost every class admits an effective enumeration in terms of speedy devices. Finally complexity classes are shown to not be closed under intersection.
recursion abstraction complexity class version proven measurement effect device intersection