The parameterized problem p-Halt takes as input a nondeterministic Turing machine M and a natural number n, the size of M being the parameter. It asks whether every accepting run of M on empty input tape takes more than n steps. This problem is in the class XPuni, the class “uniform XP,” if there is an algorithm deciding it, which for fixed machine M runs in time polynomial in n. It turns out t...

In this paper, we improve some previous definitions of fuzzy-type Turing machines to obtain degrees of accepting and rejecting in a computational manner. We apply a BFS-based search method and some level’s upper bounds to propose a computational process in calculating degrees of accepting and rejecting. Next, we introduce the class of Extended Fuzzy Turing Machines equipped with indeterminacy s...

The halting set Kr = (x I r converges}, for any G6del numbering ~ = {~0, ~1 ,-..}, is nonrecursive. It may be possible, however, to approximate Kr by recursive s e t s . We note several results indicating that the degrees of recursive approximability of halting sets in arbitrary GSdel numberings have wide variation, while restriction to "optimal GSdel numberings" only narrows the possibilities ...