Summary
The following results are proved by the use of transformabilities.
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1.
NTAPE (log n)=TAPE (log n)⇔There exists a j such that every language accepted by a nondeterministic one-way one-counter automaton is contained in D j. (D j is the family of all languages accepted by deterministic j-head two-way finite automata.)
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2.
NTAPE (n) =TAPE (n)⇔ There exists a j such that every language L ∉ {1}* accepted by a nondeterministic 5-head two-way finite automaton is contained in D j.
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3.
\(\mathop U\limits_d\) TIME (n d=TAPE (log n)⇔ There exists a j such that every language accepted by a deterministic 1-head two-way pushdown automaton is contained in D j.
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4.
f\(\mathop U\limits_d\) TIME (d n)=TAPE (n)⇔There exists a j such that every language L ⊂{1}* accepted by a deterministic 1-head two-way pushdown automaton is contained in D j.
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5.
D j ≨ D j+1 for all j ε εN.
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Monien, B. Transformational methods and their application to complexity problems. Acta Informatica 6, 95–108 (1976). https://doi.org/10.1007/BF00263746
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DOI: https://doi.org/10.1007/BF00263746