Alternating One-Way Multihead Turing Machines with Only Universal States

Shunichi SAKURAYAMA  Hiroshi MATSUNO  Katsushi INOUE  Itsuo TAKANAMI  Hiroshi TANIGUCHI  

Publication
IEICE TRANSACTIONS (1976-1990)   Vol.E68   No.10   pp.705-711
Publication Date: 1985/10/25
Online ISSN: 
DOI: 
Print ISSN: 0000-0000
Type of Manuscript: PAPER
Category: Automata and Languages
Keyword: 


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Summary: 
This paper introduces a space bounded alternating one-way multihead Turing machine with only universal states, and investigates fundamental properties of this machine. We show for example that for any function L such that [L(n)/n]0, (1) there is a set in [U2-HTM(0)], but not in [Nk-HTM(L(n))], and there is a set in [N2-HTM(0)], but not in [Uk-HTM(L(n))], (2) for each k1, [Uk-HTM(L(n))][U(k+1)-HTM(L(n))], and (3) [Uk-HTM(L(n))][Nk-HTM(L(n))][Dk-HTM(L(n))], where [Uk-HTM(L(n))] denotes the class of sets accepted by L(n) space bounded alternating one-way k-head Turing machines with only universal states, and [Nk-HTM(L(n))]([Dk-HTM(L(n))] denotes the class of sets accepted by L(n) space bounded nondeterministic (deterministic) one-way k-head Turing machines.