Zobrazeno 1 - 10
of 56
pro vyhledávání: '"77"'
Publikováno v:
Engelfriet, J & Schmidt, E M 1977, ' IO and OI. I ', Journal of Computer and System Sciences, vol. 15, no. 3, pp. 328-353 . https://doi.org/10.1016/S0022-0000(77)80034-2
A fixed-point characterization of the inside-out (IO) and outside-in (OI) context-free tree languages is given. This characterization is used to obtain a theory of nondeterministic systems of context-free equations with parameters. Several “Mezei-a
Autor:
Ming Li
Publikováno v:
FOCS
Based on graph separator theorems, we develop a new simulation technique which allows us to resolve several open problems for on-line computations: (1)One tape can nondeterministically simulate two nondeterministic pushdown stores in 0( n 1.5 √log
Autor:
Kenneth Lebensold
Publikováno v:
Journal of Combinatorial Theory, Series B. (3):207-210
In this paper, we prove a generalization of the familiar marriage theorem. One way of stating the marriage theorem is: Let G be a bipartite graph, with parts S 1 and S 2 . If A ⊂ S 1 and F ( A ) ⊂ S 2 is the set of neighbors of points in A , then
Autor:
Alan Tucker
Publikováno v:
Journal of Combinatorial Theory, Series B. (1):143-149
This paper builds on results based on D. R. Fulkerson's antiblocking polyhedra approach to perfect graphs to obtain information about critical perfect graphs and related clique-generated graphs. Then we prove that Berge's Strong Perfect Graph Conject
Autor:
S.B Rao
Publikováno v:
Journal of Combinatorial Theory, Series B. (1):1-9
Let G be a self-complementary graph of order p ≥ 8. It is shown that for every integer l, 3 ≤ l ≤ p − 2, G has an l-cycle. Further, if G is hamiltonian, then G is pancyclic.
Publikováno v:
Journal of Combinatorial Theory, Series A. (2):169-180
Let F((x)) be the field of formal power series over the field with two elements F. We classify all quadratic elements in F((x)) which are almost periodic, the Morse-Hedlund sequence being a special case. We also give some results for higher-degree al
Autor:
Ronald E. Prather
Publikováno v:
Information and Control. (2):159-171
A structured decomposition theorem for Turing machines is given. The nature of the building blocks and the form of the connections allowed suggest a parallel to the Bohm-Jacopini theorem on structured flowcharts. Thus in a broadest sense, there is ob
Autor:
Victor J. Rayward-Smith
Publikováno v:
Journal of Computer and System Sciences. (1):130-149
A new class of generative grammars called hypergrammars is introduced. They are described as a natural extension of Fischer's macrogrammars. Three modes of derivation, inside-out, outside-in, and unrestricted are considered, and the classes of langua
Autor:
Harold Fredricksen, Irving J. Kessler
Publikováno v:
Journal of Combinatorial Theory, Series A. (1):17-30
In this paper we give an algorithm to generate a new deBruijn sequence. The amount of storage required is only linear in n , the span of the sequence. We make use of the lexicographic compositions of a positive integer which we relate to binary neckl
Autor:
D. T. Busolini, Paul Erdös
Publikováno v:
Journal of Combinatorial Theory, Series B. (2-3):251-254
The number T ∗ (n,k) is the least positive integer such that every graph with n = (2k+1) + t vertices (t ≥ 0) and at least T ∗ (n,k) edges contains k mutually vertex-disjoint complete subgraphs S1, S2,…, Sk where Si has i vertices, 1 ≤ i