910 research outputs found
Towards a Systematic Account of Different Semantics for Logic Programs
In [Hitzler and Wendt 2002, 2005], a new methodology has been proposed which
allows to derive uniform characterizations of different declarative semantics
for logic programs with negation. One result from this work is that the
well-founded semantics can formally be understood as a stratified version of
the Fitting (or Kripke-Kleene) semantics. The constructions leading to this
result, however, show a certain asymmetry which is not readily understood. We
will study this situation here with the result that we will obtain a coherent
picture of relations between different semantics for normal logic programs.Comment: 20 page
A syntax for semantics in P-Lingua
P-Lingua is a software framework for Membrane Computing, it includes a
programming language, also called P-Lingua, for writting P system de nitions using a
syntax close to standard scienti c notation. The rst line of a P-Lingua le is an unique
identi er de ning the variant or model of P system to be used, i.e, the semantics of the
P system. Software tools based on P-Lingua use this identi er to select a simulation
algorithm implementing the corresponding derivation mode. Derivation modes de ne
how to obtain a con guration Ct+1 from a con guration Ct. This information is usually
hard-coded in the simulation algorithm.
The P system model also de nes what types or rules can be used, the P-Lingua
compiler uses the identi er to select an speci c parser for the le. In this case, a set of
parsers is codi ed within the compiler tool. One for each unique identi er.
P-Lingua has grown during the last 12 years, including more and more P system
models. From a software engineering point of view, this approximation implies a continous
development of the framework, leading to a monolithic software which is hard to debug
and maintain.
In this paper, we propose a new software approximation for the framework, including
a new syntax for de ning rule patterns and derivation modes. The P-Lingua users can
now de ne custom P system models instead of hard-coding them in the software. This
approximation leads to a more
exible solution which is easier to maintain and debug.
Moreover, users could de ne and play with new/experimental P system models
A Proof Theoretic View of Constraint Programming
We provide here a proof theoretic account of constraint programming that
attempts to capture the essential ingredients of this programming style. We
exemplify it by presenting proof rules for linear constraints over interval
domains, and illustrate their use by analyzing the constraint propagation
process for the {\tt SEND + MORE = MONEY} puzzle. We also show how this
approach allows one to build new constraint solvers.Comment: 25 page
Other Buds in Membrane Computing
It is well-known the huge Mario’s contribution to the development
of Membrane Computing. Many researchers may relate his name
to the theory of complexity classes in P systems, the research of frontiers
of the tractability or the application of Membrane Computing to
model real-life situations as the Quorum Sensing System in Vibrio fischeri
or the Bearded Vulture ecosystem. Beyond these research areas, in
the last years Mario has presented many new research lines which can
be considered as buds in the robust Membrane Computing tree. Many of
them were the origin of new research branches, but some others are still
waiting to be developed. This paper revisits some of these buds
Languages of lossless seeds
Several algorithms for similarity search employ seeding techniques to quickly
discard very dissimilar regions. In this paper, we study theoretical properties
of lossless seeds, i.e., spaced seeds having full sensitivity. We prove that
lossless seeds coincide with languages of certain sofic subshifts, hence they
can be recognized by finite automata. Moreover, we show that these subshifts
are fully given by the number of allowed errors k and the seed margin l. We
also show that for a fixed k, optimal seeds must asymptotically satisfy l ~
m^(k/(k+1)).Comment: In Proceedings AFL 2014, arXiv:1405.527
A Simple n-Dimensional Intrinsically Universal Quantum Cellular Automaton
We describe a simple n-dimensional quantum cellular automaton (QCA) capable
of simulating all others, in that the initial configuration and the forward
evolution of any n-dimensional QCA can be encoded within the initial
configuration of the intrinsically universal QCA. Several steps of the
intrinsically universal QCA then correspond to one step of the simulated QCA.
The simulation preserves the topology in the sense that each cell of the
simulated QCA is encoded as a group of adjacent cells in the universal QCA.Comment: 13 pages, 7 figures. In Proceedings of the 4th International
Conference on Language and Automata Theory and Applications (LATA 2010),
Lecture Notes in Computer Science (LNCS). Journal version: arXiv:0907.382
Closure properties of Watson-Crick grammars
In this paper, we define Watson-Crick context-free grammars, as an extension of Watson-Crick regular grammars and Watson-Crick linear grammars with context-free grammar rules. We show the relation of Watson-Crick (regular and linear) grammars to the sticker systems, and study some of the important closure properties of the Watson-Crick grammars. We establish that the Watson-Crick regular grammars are closed under almost all of the main closure operations, while the differences between other Watson-Crick grammars with their corresponding Chomsky grammars depend on the computational power of the Watson-Crick grammars which still need to be studied
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