Scheduled System Maintenance
On Friday, September 21, IEEE Xplore will undergo scheduled maintenance. Users may experience intermittent access from 2:30–4:00 pm ET (6:30–8:00 UTC). The site may be unavailable for approximately 60 minutes during this period.
We apologize for any inconvenience.

[1989] Proceedings. Structure in Complexity Theory Fourth Annual Conference

19-22 June 1989

Filter Results

Displaying Results 1 - 25 of 31
  • Hardness vs. randomness-a survey

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (28 KB)

    Summary form only given, as follows. Probabilistic algorithms are considered to be as practical as deterministic ones for solving computational problems. However, obvious practical and theoretical considerations have led to the questions of when, and at what cost, can one get rid of the randomness in these algorithms. A natural direction was to follow the lead of real computers and use determinist... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Boolean functions, invariance groups and parallel complexity

    Publication Year: 1989, Page(s):55 - 66
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (981 KB)

    The authors study the invariance groups S(f) of Boolean functions f in B/sub n/ on n variables. They give necessary and sufficient conditions for a general permutation group to be of the form S(f), for some f in B/sub n/. This leads to an almost optimal algorithm for deciding the representability of an arbitrary permutation group. For cyclic groups G<or= S/sub n/, an NC-algorithm is given for d... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The P-T-degrees of the recursive sets: lattice embeddings, extensions of embeddings and the two quantifier theory

    Publication Year: 1989, Page(s):68 - 76
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (803 KB)

    It has been shown in the literature that the two basic nondistributive lattices can be embedded in R/sub pt/, the polynomial-time turing degrees of the recursive sets. The authors introduce more general techniques to extend these results to show that every recursive lattice can be embedded in R/sub pt/. In addition to lattice theoretic representation theorems, they use the scheme of priority style... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Composition is almost as good as s-1-1

    Publication Year: 1989, Page(s):77 - 86
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (808 KB)

    The author establishes a polynomial upper bound on the time complexity of s-1-1 in programming systems with a linear time instance of composition. He also exhibits a family of acceptable such programming systems for which the upper bound is optimal. He deduces several bounds on the time complexity of composition, s-1-1, and various classes of control structures in effective or arbitrary programmin... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Proceedings. Structure in Complexity Theory Fourth Annual Conference (Cat. No.89CH2745-8)

    Publication Year: 1989
    Request permission for commercial reuse | PDF file iconPDF (630 KB)
    Freely Available from IEEE
  • The isomorphic conjecture fails relative to a random oracle

    Publication Year: 1989
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (29 KB)

    Summary form only given, as follows. L. Berman and H. Hartmanis (1977) conjectured that there is a polynomial-time computable isomorphism between any two languages m-complete (Karp complete) for NP. D. Joseph and P. Young (1985) discovered a structurally defined class of NP-complete sets and conjectured that certain of these sets (the K/sub f//sup k,/s) are not isomorphic to the standard NP-comple... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Oracles for structural properties: the isomorphism problem and public-key cryptography

    Publication Year: 1989, Page(s):3 - 14
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (833 KB)

    There exists an oracle, relative to which P not= NP and each of the following properties hold: (i) all Sigma /sup p//sub 2/-complete sets are p-isomorphic; (ii) P-inseparable pairs of sets in NP do not exist; (iii) intractable public-key cryptosystems do not exist; and (iv) NP-complete sets are closed under union of disjoint sets. Remarkably, these properties all follow from one oracle constructio... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On polynomial time Turing and many-one completeness in PSPACE

    Publication Year: 1989, Page(s):15 - 23
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (533 KB)

    The different between polynomial-time-Turing- and polynomial-time-many-one-completeness notions in PSPACE is shown from each of the following assumptions: (i) a randomized completeness notion differs from a deterministic one in PSPACE; and (ii) PSPACE has a dense set, almost every element of which is hard to produce by any polynomial-time computation. A. Mayer and M. Paterson (Tech. Rep. MIT/LCS/T... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • p-creative sets vs. p-completely creative sets

    Publication Year: 1989, Page(s):24 - 33
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (795 KB)

    It is shown that for recursively enumerable sets, p-creativeness and p-complete creativeness are equivalent, and Myhill's theorem still holds in the polynomial setting. For P (NP), p-creativeness is shown to be equivalent to p-complete creativeness. The existence of p-creative sets for P (NP) in EXP (NEXP) is given. Moreover, it is shown that every p-m-complete set for EXP (NEXP) is p-completely c... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the theory of average case complexity

    Publication Year: 1989
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (29 KB)

    Summary form only given, as follows. The authors take the next step in developing the theory of average case complexity initiated by L.A. Levin. Previous work has focused on the existence of complete problems. The present authors widen the scope to other basic questions in computational complexity. Their results include: (1) the equivalence of search and decision problems in the context of average... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Almost everywhere high nonuniform complexity

    Publication Year: 1989, Page(s):37 - 53
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1022 KB)

    Investigates the distribution of nonuniform complexities in uniform complexity classes. The author proves that almost every problem decidable in exponential space has essentially maximum circuit-size and program-size complexity almost everywhere. In exponential-time complexity classes, he proves that the strongest relativizable lower bounds hold almost everywhere for almost all problems. He shows ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Finitary substructure languages with application to the theory of NP-completeness

    Publication Year: 1989, Page(s):87 - 96
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (684 KB)

    Decision problems that involve the search for a fixed, finite amount of information hidden somewhere in the input are considered. In terms of polynomial complexity these finitary substructure languages (k-SLs) are much like tally sets. For instance, every k-SL A p-Turing reduces to a canonically associated set T/sub Lambda /, and so cannot be NP-hard unless the polynomial hierarchy collapses to it... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The power of parallel random access machines with augmented instruction sets

    Publication Year: 1989, Page(s):97 - 103
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (587 KB)

    It is proved that the class of languages accepted in polynomial time by a parallel random access machine (PRAM) with both multiplication and shifts contains NEXPTIME and is contained in EXPSPACE. Thus, such a PRAM may be more powerful, to within a polynomial in time, that one with either multiplication or shifts alone. Bounds are established on the simulation of PRAMs with augmented instruction se... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The complexity of iterated multiplication

    Publication Year: 1989, Page(s):104 - 111
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (546 KB)

    The complexity of multiplying together n elements of a group G is studied. It is observed that as G ranges over a sequence of well-studied groups, the iterated multiplication problem is complete for corresponding well-studied complexity classes. Furthermore, the notion of completeness in question is extremely low-level and algebraic. The issue of uniformity is investigated.<<ETX>> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The complexity of circuit value and network stability

    Publication Year: 1989, Page(s):114 - 123
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (739 KB)

    A method for nontrivially restricting fanout in a circuit is developed. The complexity of the circuit value problem and a new problem, network stability, is studied when fanout is limited. This leads to new classes or problems within P. It is conjectured that the new classes are different from P and incomparable to NC. One of these classes, CC, contains several natural complete problems, including... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Decomposing NC and AC

    Publication Year: 1989, Page(s):124 - 131
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (498 KB)

    It is shown that it is possible to decompose any level of NC into components involving lower levels. The results are extended to the class AC. The method presented results in a natural way to provide NC and AC with oracles.<<ETX>> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On finding locally optimal solutions

    Publication Year: 1989, Page(s):132 - 137
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (307 KB)

    The problem of finding locally optimal solutions to combinatorial problems in the framework of polynomial-time local search as defined by D.S. Johnson et al. (J. Comput. Syst. Sci., vol.37, no.1, p.79-100, Aug. 1988) is considered. A PLS-complete problem such that the problem of verifying local optimality can be solved in LOGSPACE is exhibited. For all previously known PLS-complete problems, verif... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The complexity of the real line is a fractal

    Publication Year: 1989, Page(s):138 - 146
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (433 KB)

    The authors investigate the Kolmogorov complexity of real numbers. They determine the Hausdorff dimension and the topological dimension of the graph of K, the Kolmogorov complexity function. They conclude that the complexity graph is a fractal.<<ETX>> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Results on communication complexity classes

    Publication Year: 1989, Page(s):148 - 157
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (705 KB)

    The authors consider deterministic, probabilistic, nondeterministic, and alternating complexity classes defined by polylogarithmic communication. They give a simple technique allowing translation of most known separation and containment results for complexity classes of the fixed-partition model to the more difficult optimal partition model, for which few results were previously known. They demons... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multi-oracle interactive protocols with space bounded verifiers

    Publication Year: 1989, Page(s):158 - 164
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (510 KB)

    It is proved that both in the multiprover model of M. Ben-or et al. (Proc. 20th Symp. Theory Comput., 1988, p.113-131) and in the the noisy oracle model of U. Feige et al. (Proc. CRYPTO 88) a finite-state verifier can accept any recursive language. The power of verifiers with simultaneous time bounds and space bounds is considered as well.<<ETX>> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Inductive reasoning and Kolmogorov complexity

    Publication Year: 1989, Page(s):165 - 185
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1870 KB)

    The inductive reasoning concepts of R.J. Solomonoff (Inf. Control. vol.7, p.1-22, 224-254, 1964) are considered. The thesis is developed that Solomonoff's method is fundamental in the sense that many other induction principles can be viewed as particular ways to obtain computable approximations to it. This is demonstrated explicitly in the cases of E.M. Gold's (1967, 1978) paradigm for inductive i... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The generalized Kolmogorov complexity of sets

    Publication Year: 1989, Page(s):186 - 194
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (474 KB)

    Recent work has shown that it is useful to consider new variants of time-bounded Kolmogorov complexity. The author reviews that work, presents the new definitions, and studies the basic properties of these measures. He deals with the function K/sub L/, which measures the complexity of the simplest strings in the language L and with sets of the form KU/sub v/(s(n),t(n)), which consists of strings w... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On honest polynomial reductions, relativizations, and P=NP

    Publication Year: 1989, Page(s):196 - 207
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (837 KB)

    The authors prove a number of structural theorems about the honest polynomial m-degrees, contingent on the assumption P=NP (or a unary alphabet). The ultimate goal would be to prove a contradiction from P=NP. They show that low sets cannot be minimal with respect. They also show that some theorems about honest polynomial reductions do not relativize; hence, techniques in this area may be able to r... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Turning machines with few accepting computations and low sets for PP

    Publication Year: 1989, Page(s):208 - 215
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (496 KB)

    The authors study two different ways to restrict the power of NP. They consider languages accepted by nondeterministic polynomial-time machines with a small number of accepting paths in case of acceptance, and they investigate three subclasses of NP that are low for complexity classes not known to be in the polynomial-time hierarchy. The subclasses, UP, FewP, and Few, are all defined in terms of n... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the relativized power of additional accepting paths

    Publication Year: 1989, Page(s):216 - 224
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (579 KB)

    The author defines U/sub k(n)/P as the class of languages in NP that are accepted by machines with at most k(n) accepting paths on each input of length n. Then P contained in UP contained in U/sub k(n)/P contained in U/sub k(n)+1/P contained in FewP $4 for every polynomial k(n)>or=2, where FewP is the class of languages in NP that are accepted by machines with a polynomial-bounded number of acc... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.