Characterizations of Pushdown Machines in Terms of Time-Bounded Computers
Journal of the ACM (JACM)
A Note on Tape-Bounded Complexity Classes and Linear Context-Free languages
Journal of the ACM (JACM)
On the Tape Complexity of Deterministic Context-Free Languages
Journal of the ACM (JACM)
Propositional modal logic of programs
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
A characterization of the power of vector machines
STOC '74 Proceedings of the sixth annual ACM symposium on Theory of computing
Path systems and language recognition
STOC '70 Proceedings of the second annual ACM symposium on Theory of computing
General context-free language recognition.
General context-free language recognition.
Cost Trade-offs in Graph Embeddings, with Applications
Journal of the ACM (JACM)
An Improved Context-Free Recognizer
ACM Transactions on Programming Languages and Systems (TOPLAS)
Measures of parallelism in alternating computation trees (Extended Abstract)
STOC '81 Proceedings of the thirteenth annual ACM symposium on Theory of computing
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The size of an accepting computation tree of an alternating Turing machine (ATM) is introduced as a complexity measure. Tree-size on ATM's is shown to closely correspond to time on nondeterministic TM's and on nondeterministic auxiliary pushdown automata. The later gives a useful new characterization of the class of languages log-space-reducible to context-free languages. Relationships with parallel-time complexity are also explored. ATM computations using at most space S(n) and tree-size Z(n) (simultaneously) can be simulated in alternating time S(n).log Z(n). Several well-known simulations, e.g., Savitch's theorem, are special cases of this result. It also leads to improved parallel-time bounds for many problems, e.g., context-free language recognition in time 0(log2n) on several parallel models.