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22
The Expressiveness of a Family of Finite Set Languages
 IN PROCEEDINGS OF 10TH ACM SYMPOSIUM ON PRINCIPLES OF DATABASE SYSTEMS
, 1991
"... In this paper we characterise exactly the complexity of a set based database language called SRL, which presents a unified framework for queries and updates. By imposing simple syntactic restrictions on it, we are able to express exactly the classes, P and LOGSPACE. We also discuss the role of orde ..."
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Cited by 26 (3 self)
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In this paper we characterise exactly the complexity of a set based database language called SRL, which presents a unified framework for queries and updates. By imposing simple syntactic restrictions on it, we are able to express exactly the classes, P and LOGSPACE. We also discuss the role of ordering in database query languages and show that the hom operator of Machiavelli language in [OBB89] does not capture all the orderindependent properties.
Semantics vs. Syntax vs. Computations  Machine Models For Type2 . . .
 JOURNAL OF COMPUTER AND SYSTEM SCIENCE
, 1997
"... This paper investigates analogs of the KreiselLacombeShoenfield Theorem in the context of the type2 basic feasible functionals. We develop a direct, polynomialtime analog of effective operation in which the time boundingon computations is modeled after Kapron and Cook's scheme for their bas ..."
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Cited by 10 (0 self)
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This paper investigates analogs of the KreiselLacombeShoenfield Theorem in the context of the type2 basic feasible functionals. We develop a direct, polynomialtime analog of effective operation in which the time boundingon computations is modeled after Kapron and Cook's scheme for their basic polynomialtime functionals. We show that if P = NP, these polynomialtime effective operations are strictly more powerful on R (the class of recursive functions) than the basic feasible functions. We also consider a weaker notion of polynomialtime effective operation where the machines computing these functionals have access to the computations of their procedural parameter, but not to its program text. For this version of polynomialtime effective operations, the analog of the KreiselLacombeShoenfield is shown to holdtheir power matches that of the basic feasible functionals on R.
Extending the Loop Language with HigherOrder Procedural Variables
 Special issue of ACM TOCL on Implicit Computational Complexity
, 2010
"... We extend Meyer and Ritchie’s Loop language with higherorder procedures and procedural variables and we show that the resulting programming language (called Loop ω) is a natural imperative counterpart of Gödel System T. The argument is twofold: 1. we define a translation of the Loop ω language int ..."
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Cited by 9 (6 self)
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We extend Meyer and Ritchie’s Loop language with higherorder procedures and procedural variables and we show that the resulting programming language (called Loop ω) is a natural imperative counterpart of Gödel System T. The argument is twofold: 1. we define a translation of the Loop ω language into System T and we prove that this translation actually provides a lockstep simulation, 2. using a converse translation, we show that Loop ω is expressive enough to encode any term of System T. Moreover, we define the “iteration rank ” of a Loop ω program, which corresponds to the classical notion of “recursion rank ” in System T, and we show that both translations preserve ranks. Two applications of these results in the area of implicit complexity are described. 1
On the Expressive Power of the Loop Language
 Nordic Journal of Computing
, 2006
"... imperative programming language similar to the Loop language described by Meyer and Ritchie ..."
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Cited by 4 (4 self)
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imperative programming language similar to the Loop language described by Meyer and Ritchie
Extensible Attribute Grammars
, 1992
"... This report introduces a new idea to make attribute grammars (AG) extensible. Both the contextfree grammar and the attribution system of an AG may be extended. This concept is a valuable structuring technique when defining languagebased programming environments or compilers. For instance, it allow ..."
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Cited by 4 (3 self)
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This report introduces a new idea to make attribute grammars (AG) extensible. Both the contextfree grammar and the attribution system of an AG may be extended. This concept is a valuable structuring technique when defining languagebased programming environments or compilers. For instance, it allows passes of a multipass compiler to be decomposed into different grammar levels, which renders the definition much clearer. Another application consists of defining an interface for an external tool (browser) on an independent grammar level neatly separated from the actual language definition. The concept of extensible attribute grammars is first introduced using a formal model, and thereafter practical examples demonstrate possible applications.
Computing nilpotent quotients in finitely presented Lie rings
 DISCRETE MATH. THEOR. COMPUT. SCI
, 1997
"... ..."
Code Problems on Traces
 Szalas (Eds.), Proc. 21st Internat. Sympos. on Mathematical Foundations of Computer Science (MFCS'96), Lecture Notes in Comput. Sci
, 1996
"... . The topic of codes in the framework of trace monoids leads to interesting and challenging decision problems of combinatorial flavour. We give an overview of the current state of some basic questions in this field. Among these, we consider the existence problem for strong codings, cliquepreserving ..."
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Cited by 2 (0 self)
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. The topic of codes in the framework of trace monoids leads to interesting and challenging decision problems of combinatorial flavour. We give an overview of the current state of some basic questions in this field. Among these, we consider the existence problem for strong codings, cliquepreserving morphisms and the unique decipherability problem (code problem). 1 Introduction Free partially commutative monoids [7] offer a mathematically sound framework for modelling and analyzing concurrent systems. This was made popular by the work of Mazurkiewicz. He investigated originally the behaviour of safe 1labelled Petri nets [17] and the computer science community quickly recognized the importance of this work. The basic concept is to consider a system as a finite set of actions \Sigma , together with a fixed symmetric independence relation I ` \Sigma \Theta \Sigma , denoting pairs of actions which can be scheduled in parallel. In the setting defined by a pair (\Sigma ; I) we identify seq...
Information processing, computation, and cognition
 JOURNAL OF BIOLOGICAL PHYSICS
"... Computation and information processing are among the most fundamental notions in cognitive science. They are also among the most imprecisely discussed. Many cognitive scientists take it for granted that cognition involves computation, information processing, or both – although others disagree veheme ..."
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Cited by 1 (1 self)
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Computation and information processing are among the most fundamental notions in cognitive science. They are also among the most imprecisely discussed. Many cognitive scientists take it for granted that cognition involves computation, information processing, or both – although others disagree vehemently. Yet different cognitive scientists use ‘computation ’ and ‘information processing ’ to mean different things, sometimes without realizing that they do. In addition, computation and information processing are surrounded by several myths; first and foremost, that they are the same thing. In this paper, we address this unsatisfactory state of affairs by presenting a general and theoryneutral account of computation and information processing. We also apply our framework by analyzing the relations between computation and information processing on one hand and classicism and connectionism/computational neuroscience on the other. We defend the relevance to cognitive science of both computation, at least in a generic sense, and information processing, in three important senses of the term. Our account advances several foundational debates in cognitive science by untangling some of their conceptual knots in a theoryneutral way. By leveling the playing field, we pave the way for the future resolution of the debates ’ empirical aspects.
Neural computation and the computational theory of cognition. Cognitive science
, 2012
"... We begin by distinguishing computationalism from a number of other theses that are sometimes conflated with it. We also distinguish between several important kinds of computation: computation in a generic sense, digital computation, and analog computation. Then, we defend a weak version of computati ..."
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We begin by distinguishing computationalism from a number of other theses that are sometimes conflated with it. We also distinguish between several important kinds of computation: computation in a generic sense, digital computation, and analog computation. Then, we defend a weak version of computationalism—neural processes are computations in the generic sense. After that, we reject on empirical grounds the common assimilation of neural computation to either analog or digital computation, concluding that neural computation is sui generis. Analog computation requires continuous signals; digital computation requires strings of digits. But current neuroscientific evidence indicates that typical neural signals, such as spike trains, are graded like continuous signals but are constituted by discrete functional elements (spikes); thus, typical neural signals are neither continuous signals nor strings of digits. It follows that neural computation is sui generis. Finally, we highlight three important consequences of a proper understanding of neural computation for the theory of cognition. First, understanding neural computation requires a specially designed mathematical theory (or theories) rather than the mathematical theories of analog or digital computation. Second, several popular views about neural computation turn out to be incorrect. Third, computational theories of cognition that rely on nonneural notions of computation ought to be replaced or reinterpreted in terms of neural computation.