Showing papers in "Theoretical Computer Science in 1976"

TL;DR: This paper shows that a number of NP - complete problems remain NP -complete even when their domains are substantially restricted, and determines essentially the lowest possible upper bounds on node degree for which the problems remainNP -complete.

TL;DR: The problem of deciding validity in the theory of equality is shown to be complete in polynomial-space, and close upper and lower bounds on the space complexity of this problem are established.

TL;DR: New proofs of two properties of the polynomial-time hierarchy are given, where the classes in the hierarchy are characterized using polynomially bounded quantifiers.

TL;DR: This paper provides a linear-time algorithm for computing an st-numbering for any biconnected graph and can be combined with some new results by Booth and Lueker to provide alinear-time implementation of the Lempel-Even-Cederbaum planarity-testing algorithm.

TL;DR: The reachability set for vector addition systems of dimension less than or equal to five are shown to be effectively computable semilinear sets, and reachability, equvalence and containment are decidable up to dimension 5.

TL;DR: A variety of familiar problems are shown complete for P, including context-free emptiness, infiniteness and membership, establishing inconsistency of propositional formulas by unit resolution, deciding whether a player in a two-person game has a winning strategy, and determining whether an element is generated from a set by a binary operation.

TL;DR: A non-constructive argument (not based on the construction of an “oracle”) settles this question for d a prime power: at least v216 entries of the adjacency matrix of a v-vertex undirected graph G must be examined in the worst case to determine if G has any given non-trivial monotone graph property.

TL;DR: If X and Y are n element sets of real numbers, then the n 2 element set X + Y can be sorted with O ( n 2 ) comparisons, improving upon the n2 log 2 n bound established by Harper et al.

TL;DR: The average number of digits in the k th largest prime factor of a random m -digit number is shown to be asymptotically equivalent to the average length of the kTh longest cycle in a permutation on m objects.

TL;DR: The usefulness of Petri nets for treating problems about vector addition systems is demonstrated by giving a simple exposition of Rabin's proof of the undecidability of the inclusion problem for vector addition system reachability sets.

TL;DR: Two algorithms are proved to compute the closure of a matrix oven any closed semiring using a generalization of algorithms by Warshall, Floyd and Kleene and a generalized version of Dijkstra algorithm.

TL;DR: Loveland's method shows that this is no longer a sufficient condition for x to be recursive if one merely stipulates that K ( x n ) ⩽ K ( n ) + c for infinitely many n.

TL;DR: The question to decide whether a given Petri net is consistent, Mo-reversible or live is reduced to the reachability problem in a unified manner.

TL;DR: The problem of inducing an algorithm for a partial recursive function from the analysis of its graph or loosely speaking of “learning” it, is discussed.

TL;DR: The main result can be described as follows: for every e 0 one can construct a polynomial-time algorithm for each of the above problems such that the ratio of the value of the objective function by this algorithm and the optimal value is bounded below by 1 - e.

TL;DR: A certain mathematical model of information storage and retrieval system based on a certain family of languages intermediate between sentential and predicate calculi, which investigates these languages from the logical point of view showing their completeness by exhibiting nice and natural sets of axioms.

TL;DR: Resume On applique la theorie de S. Eilenberg au moyen de la methode des transducteurs de M. Nivat pour obtenir quelques indications sur the vitesse de croissance en fonction of the longueur du mot du nombre de mots de l'image d'une relation rationnelle.

TL;DR: It is shown that the inclusion problems for the LL(k) languages and the free monadic recursion schemes that do not use an identity function are also undecidable.

TL;DR: A general lower bound on the minimal number of additions in monotone, rational computations is proved, which implies that anymonotone rational computation of the n th degree convolution at least requires n 2 − 2 n + 1 additions.

TL;DR: For classes of languages accepted in polynomial time by multicounter machines, various trade-offs in computing power obtain among the number of counters, the amount of time, and the time required in all cases, deterministic and nondeterministic, on-line and off-line.

TL;DR: This paper deals with the problems of applying a unification procedure in a mechanization of the full type theory and an extensive proof of completeness of the algorithm is presented.

TL;DR: A well-known theorem of Eerstel which gives a necessary condition for positiveness is also essentially sufficient and makes it possible to answer some problems appearing in EileGerg and to decide the -rationality of a -rational sequence.

TL;DR: The aim of this paper is to generalize a result given by Curry and Feys, showing that the only regular combinators possessing inverse in the λ-β-η-calculus are the permutators, whose definition is p=λzλx1…λxn(zxi1…xin) for n⩾0 where i1,…, ir is a permutation of 1,….

TL;DR: A notion of computability on continuous higher types is defined and its equivalence to effective operators is shown and it is shown that the authors' computable operators can model mathematically everything that can be done in an operational semantics.

TL;DR: It is shown that the languages recognized by two-way deterministic FAM's are of tape complexity log n and time complexity n 3 .

TL;DR: It is shown that Valiant's partial procedure for equivalence can be made constructive and the time complexity of the algorithm is bounded by a double exponential function of the size of the input.

TL;DR: The Church-Rosser approach to correctness of asynchronous parallel programs is a flexible way to divide a correctness proof into several lemmas, no one of which requires both deep reasoning and explicit enumeration of all the control states required in the nondeterministic sequential form of the program.

TL;DR: This paper provides a method of “decomposing” a subclass of ET0L languages into deterministic ET1L languages, which allows one to use every known example of a language which is not a deterministicET0L language to produce languages which are not ET0l languages.

TL;DR: Translational lemmas are stated in a general framework and then applied to specific complexity classes, and necessary and sufficient conditions are given for every set accepted by a Turing acceptor which operates in linear or polynomial time.