An elementary formal system (EFS) is a logic program such as a Prolog program, for instance, that directly manipulates strings. Arikawa and his co-workers proposed elementary formal systems as a unifying framework for formal language learning.

An elementary formal system (EFS) is a logic program such as a Prolog program, for instance, that directly manipulates strings.

An elementary formal system (EFS , for short) is a kind of logic program which directly manipulates character strings. A number of researches have investigated the ability of EFS as an uniform framework for language learning in various learning models including model inference, inductive

An elementary formal system ( $EFS $ , for short) [8] is suitable to generate various for-mal languages [3]. The EFS has been investigated from the various viewpoints $[4, 11] $. In particular, from the viewpoints of translations on formal languages, Sugimoto and Ishizaka $[9, 10] $ have pointed

An elementary formal system (EFS) is a logic program con- sisting of definite clauses whose arguments have patterns instead of first-order terms. We investigate EFSs for polynomial-time PAC-learnability. A definite clause of an EFS is hereditary if every pattern in the body is a subword of a

Recently, rich subclasses of elementary formal systems (EFS) have been shown to be identifiable in the limit from only positive data. Examples of these classes are Angluin’s pattern languages, unions of pattern languages by Wright and Shinohara, and classes of languages definable by length

shall use the generic term information systems, in its broadest sense, to collectively refer to these application perspectives. We argue in this paper that so-called ontologies present their own methodological and architectural peculiarities: on the methodological side, their main peculiarity

We present a broad extension of the conventional formalism of state machines and state diagrams, that is relevant to the specification and design of complex discrete-event systems, such as multi-computer real-time systems, communication protocols and digital control units. Our diagrams, which we

In learning their native language, children develop a remarkable set of capabilities. They acquire knowledge and skills that enable them to produce and comprehend an indefinite number of novel utterances, and to make quite subtle judgments about certain of their properties. The major goal of psycholinguistic research is to devise an explanatory account of the mental operations that underlie these linguistic abilities. In pursuing this goal, we have adopted what we call the Competence Hypothesis as a methodological principle. We assume that an explanatory model of human language performance will incorporate a theoretically justi ed representation of the native speaker's linguistic knowledge (a grammar) as a component separate both from the computational mechanisms that operate on it (a processor) and from other nongrammatical processing parameters that might influence the processor's behavior. To a certain extent the various components that we postulate can be studied independently, guided where appropriate by the well-established methods and evaluation standards of linguistics, computer science, and experimental psychology. However, the requirement that the various components ultimately must fit together in a consistent and coherent model imposes even stronger constraints on their structure and operation.

sections. Section I describes desired functions, design principles, and examples of elementary protection and authentication mechanisms. Any reader familiar with computers should find the first section to be reasonably accessible. Section II requires some familiarity with descriptor-based computer