1,721,063 research outputs found
Experimental suggestion and suggestibility in the categorization of ambigous figural patterns
No full textA compositional Semantics for CHR
No full textConstraint Handling Rules (CHR) is a committed-choice declarative language which has been
designed for writing constraint solvers. A CHR program consists of multiheaded guarded rules
which allow to rewrite constraints into simpler ones until a solved form is reached.
CHR has received considerable attention, both from the practical and from the theoretical side.
Nevertheless, due the use of multiheaded clauses, there are several aspects of the CHR semantics
which have not been clarified yet. In particular, no compositional semantics for CHR has been
defined so far.
In this article we introduce a fix-point semantics which characterizes the input/output behavior
of a CHR program and which is and-compositional, that is, which allows to retrieve the semantics
of a conjunctive query from the semantics of its components. Such a semantics can be used as a
basis to define incremental and modular analysis and verification tools.
Categories and Subject Descriptors: D.3.1 [Programming Languages]: Formal Definitions and
Theory—Semantics; D.3.3 [Programming Languages]: Language Constructs and Features—
Constraints
General Terms: Languages, Theory
Additional Key Words and Phrases: Semantic
Rule based instruction, learning and recognition:Verifying on children the Anderson's theory of learning
No full textI processi dominio-indipendenti e dominio-specifici nel ragionamento induttivo e nell'intelligenza
No full text
Compositionality properties of SLD-derivations
No full textThe paper introduces a semantics for definite logic programs expressed in terms of SLD-derivations and studies various properties of SLD-derivations by using the above semantics, The semantics of a program is a goal-independent denotation, which can equivalently be specified by a denotational semantics and a transition system. The denotation is proved to be correct, minimal, AND-compositional and OR-compositional. The denotational semantics and the transition system are defined in terms of a set of primitive semantic operators, whose properties are directly related to the properties of the denotation. The SLD-derivations semantics has been designed to act as collecting semantics for a framework of abstract semantics (Comini et al., 1995, 1996). (C) 1999-Elsevier Science B.V. All rights reserved
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