Search results for " Computer Science"
showing 10 items of 3983 documents
The power of formalization and abstraction in evolutionary biologyThe Geometry of Evolution: Adaptive Landscapes and Theoretical Morphospaces. (2006)…
2007
The Crane Beach Conjecture
2002
A language L over an alphabet A is said to have a neutral letter if there is a letter e/spl isin/A such that inserting or deleting e's from any word in A* does not change its membership (or non-membership) in L. The presence of a neutral letter affects the definability of a language in first-order logic. It was conjectured that it renders all numerical predicates apart from the order predicate useless, i.e., that if a language L with a neutral letter is not definable in first-order logic with linear order then it is not definable in first-order. Logic with any set /spl Nscr/ of numerical predicates. We investigate this conjecture in detail, showing that it fails already for /spl Nscr/={+, *…
Monadic second-order logic over pictures and recognizability by tiling systems
1994
We show that a set of pictures (rectangular arrays of symbols) is recognized by a finite tiling system if and only if it is definable in existential monadic second-order logic. As a consequence, finite tiling systems constitute a notion of recognizability over two-dimensional inputs which at the same time generalizes finite-state recognizability over strings and matches a natural logic. The proof is based on the Ehrenfeucht-FraIsse technique for first-order logic and an implementation of “threshold counting” within tiling systems.
Process specification and verification
1996
Graph grammars provide a very convenient specification tool for distributed systems of processes. This paper addresses the problem how properties of such specifications can be proven. It shows a connection between algebraic graph rewrite rules and temporal (trace) logic via the graph expressions of [2]. Statements concerning the global behavior can be checked by local reasoning.
Monadic Second-Order Logic over Rectangular Pictures and Recognizability by Tiling Systems
1996
Abstract It is shown that a set of pictures (rectangular arrays of symbols) is recognized by a finite tiling system iff it is definable in existential monadic second-order logic. As a consequence, finite tiling systems constitute a notion of recognizability over two-dimensional inputs which at the same time generalizes finite-state recognizability over strings and also matches a natural logic. The proof is based on the Ehrenfeucht–Fraisse technique for first-order logic and an implementation of “threshold counting” within tiling systems.
Measure, category and learning theory
1995
Measure and category (or rather, their recursion theoretical counterparts) have been used in Theoretical Computer Science to make precise the intuitive notion “for most of the recursive sets.” We use the notions of effective measure and category to discuss the relative sizes of inferrible sets, and their complements. We find that inferrible sets become large rather quickly in the standard hierarchies of learnability. On the other hand, the complements of the learnable sets are all large.
Recent results on syntactic groups of prefix codes
2012
International audience; We give a simplified presentation of groups in transformation monoids. We use this presentation to describe two recent results on syntactic groups of prefix codes. The first one uses Sturmian words to build finite bifix codes with a given permutation group as syntactic group. The second one describes a class of prefix codes such that all their syntactic groups are cyclic.
Transducers for the bidirectional decoding of prefix codes
2010
AbstractWe construct a transducer for the bidirectional decoding of words encoded by the method introduced by Girod (1999) in [5] and we prove that it is bideterministic and that it can be used both for the left-to-right and the right-to-left decoding.We also give a similar construction for a transducer that decodes in both directions words encoded by a generalization of Girod’s encoding method. We prove that it has the same properties as those of the previous transducer. In addition we show that it has a single initial/final state and that it is minimal.
A Generalization of Girod's Bidirectional Decoding Method to Codes with a Finite Deciphering Delay
2012
Girod’s encoding method has been introduced in order to efficiently decode from both directions messages encoded by using finite prefix codes. In the present paper, we generalize this method to finite codes with a finite deciphering delay. In particular, we show that our decoding algorithm can be realized by a deterministic finite transducer. We also investigate some properties of the underlying unlabeled graph.