Showing papers by "Juris Hartmanis published in 1979"
29 Oct 1979
TL;DR: A personal account of some developments in automata theory and computational complexity theory and discusses the underlying beliefs and philosophy which guided this research as well as the intellectual environment and the ideas and contacts which influenced it.
Abstract: This paper gives a personal account of some developments in automata theory and computational complexity theory. Though the account is subjective and deals primarily with the research areas of direct interest to the author, it discusses the underlying beliefs and philosophy which guided this research as well as the intellectual environment and the ideas and contacts which influenced it. An attempt is also made to draw some general conclusions about computer science research and to discuss the nature of theoretical computer science.
19 citations
03 Sep 1979
TL;DR: It is shown that the relative succinctness of different representations of languages is directly related to the separation of the corresponding complexity classes; for example, PTIME ≠ NPTIME if and only if the relative conciseness of representing languages in PTIME by deterministic and nondeterministic clocked polynomial time machines is not recursively bounded.
Abstract: In this paper we study the relative succinctness of different representations of deterministic polynomial time languages and investigate what can and cannot be formally verified about these representations. We also show that the relative succinctness of different representations of languages is directly related to the separation of the corresponding complexity classes; for example, PTIME ≠ NPTIME if and only if the relative succinctness of representing languages in PTIME by deterministic and nondeterministic clocked polynomial time machines is not recursively bounded, which happens if and only if the relative succinctness of these representations is not linearly bounded.
12 citations
TL;DR: In this article, the authors study diagonal processes over time bounded computations of one-tape Turing machines by diagonalizing only over those machines for which there exist formal proofs that they operate in the given time bound.
10 citations
16 Jul 1979
TL;DR: The purpose of this paper is to derive some new results about how the relative succinctness of representations change when the representations contain a formal proof that the languages generated are in the desired subclass of languages.
Abstract: The purpose of this paper is to give simple new proofs of some interesting recent results about the relative succinctness of different representations of regular, deterministic and unambiguous context-free languages and to derive some new results about how the relative succinctness of representations change when the representations contain a formal proof that the languages generated are in the desired subclass of languages.
10 citations
29 Oct 1979
TL;DR: It is shown that requirements such as polynomialRunning time, verifiability of running time, and verifiable of accepting a set in P can be causes for differences in succinctness that are not recursively bounded.
Abstract: Several representations of P, the class of deterministic polynomial time acceptable languages, are compared with respect to succinctness. It is shown that requirements such as polynomial running time, verifiability of running time, and verifiability of accepting a set in P can be causes for differences in succinctness that are not recursively bounded. Relating succinctness to nondeterminism, it is shown that P ≠ NP if and only if the relative succinctness of representing languages in P by deterministic and nondeterministic clocked polynomial time machines is not recursively bounded. questions are posed, concerning the implications of P = NP, with respect to translatability and succinctness between other pairs of deterministic and nondeterministic representations for P.
8 citations