A formal device is said to be adaptive whenever its behavior changes dynamically, in a direct response to its input stimuli, without interference of external agents, even its users. In order to achieve this feature, adaptive devices have to be self-modifiable. In other words, any possible changes in the device’s behavior must be known at their full extent at any step of its operation in which the changes have to take place. Therefore, adaptive devices must be able to detect all situations causing possible modifications and to adequately react by imposing corresponding changes to the device’s behavior. In this work, devices are considered whose behavior is based on the operation of subjacent non-adaptive devices that be fully described by some finite set of rules. An adaptive rule-driven device may be obtained by attaching adaptive actions to the rules of the subjacent formulation, so that whenever a rule is applied, the associated adaptive action is activated, causing the set of rules of the subjacent non-adaptive device to be correspondingly changed. In this paper a new general formulation is proposed that unifies the representation and manipulation of adaptive rule-driven devices and states a common framework for representing and manipulating them. The main feature of this formulation is that it fully preserves the nature of the underlying non-adaptive formalism, so that the adaptive resulting device be easily understood by people familiar to the subjacent device. For illustration purposes, a two-fold case-study is presented, describing adaptive decision tables as adaptive rule-driven devices, and using them for emulating the behavior of a very simple adaptive automaton, which is in turn another adaptive rule-driven device.

(CGE), a new evolutionary automatic programming algorithm that extends standard grammar evolution (GE) by replacing context-free grammars by Christiansen grammars. GE only takes into account syntactic restrictions to generate valid individuals. CGE adds semantics to ensure that both semantically and syntactically valid individuals are generated. It is empirically shown that our approach improves GE performance and even allows the solution of some problems are difficult to tackle by GE. Index Terms—Automatic programming, formal languages, genetic algorithms (GAs), languages. I.

ive Power of Programming Languages by John N. Shutt Computer Science Technical Report Series WORCESTER POLYTECHNIC INSTITUTE Computer Science Department 100 Institute Road, Worcester, Massachusetts 01609-2280 S-Expressiveness and the Abstractive Power of Programming Languages John N. Shutt jshutt@cs.wpi.edu Computer Science Department Worcester Polytechnic Institute Worcester, MA 01609 December 1999 Abstract This paper investigates possible approaches to developing a mathematical model of the process of abstraction in programming. In particular, two formal measures are considered for comparing the relative abstractive power of programming languages. A measure called expressiveness, proposed elsewhere by M. Felleisen, is found insufficient for the current task because it is concerned with expression only of runtime semantics. A second measure called S-expressiveness, defined here, doesn't fully capture abstractive power either, but its shortcomings are differe...

ion in Programming --- working definition by John N. Shutt Computer Science Technical Report Series WORCESTER POLYTECHNIC INSTITUTE Computer Science Department 100 Institute Road, Worcester, Massachusetts 01609-2280 Abstraction in Programming --- working definition John N. Shutt jshutt@cs.wpi.edu Computer Science Department Worcester Polytechnic Institute Worcester, MA 01609 December 1999 Abstract This paper investigates the nature of the process in programming by which a new level of abstraction is constructed by building upon an existing one. The process is called abstraction. The purpose of the investigation is to provide an informal characterization of abstraction, as a conceptual foundation for subsequent development of a mathematical theory of abstraction. Contents 1 Introduction 1 2 Other senses of `abstraction' 1 2.1 Metaphysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2.1.1 Universals . . . . . . . . . . . . . . . . . . . . . ....

We introduce a fifth language accepting machine called the PDA-T, demonstrate some of its interesting formal properties, and show its role in the $-Calculus( Based upon this new machine and the $-Calculus' other properties, we demonstrate the $-Calculus' formal Turing Power, and then propose a formal language classification (the $-Hierarchy), derived largely from the Chomsky Hierarchy, but with a fifth class of language accepted by the PDA-T. We show that this modified hierarchy yields several conceptual benefits over the standard four machine Chomsky Hierarchy. We also provide some practical examples of the use of $-grammars in contextsensitive and semantic parsing.

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We examine the usefulness of the Meta-S Calculus as a formalism for natural language parsing, and in particular the power of a single adaptive predicate in a structure-only English grammar in providing document wide context resolution. We were able to construct an Meta-S grammar for a limited subset of English that a) contained no English words at start, and b) correctly parsed a series of twenty-two sentences without the use of any mechanism outside the formalism of the Meta-S grammar itself.