Accession Number : ADA096556


Title :   The Definition and Implementation of a Computer Programming Language Based on Constraints.


Descriptive Note : Technical rept.,


Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB


Personal Author(s) : Steele,Guy Lewis , Jr


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a096556.pdf


Report Date : Aug 1980


Pagination or Media Count : 372


Abstract : The constraint paradigm is a model of computation in which values are deduced whenever possible, under the limitation that deductions be local in a certain sense. One may visualize a constraint 'program' as a network of devices connected by wires. Data values may flow along the wires, and computation is performed by the devices. A device computes using only locally available information (with a few exceptions), and places newly derived values on other, locally attached wires. In this way computed values are propagated. An advantage of the constraint paradigm (not unique to it) is that a single relationship can be used in more than one direction. The connections to a device are not labelled as inputs and outputs; a device will compute with whatever values are available, and produce as many new values as it can. General theorem provers are capable of such behavior, but tend to suffer from combinatorial explosion; it is not usually useful to derive all the possible consequences of a set of hypotheses. The constraint paradigm places a certain kind of limitation on the deduction process. A number of implementations of constraint-based programming languages are presented.


Descriptors :   *METHODOLOGY , *COMPUTER PROGRAMMING , *PROGRAMMING LANGUAGES , DATA PROCESSING , DATA MANAGEMENT , THESES , CIRCUIT INTERCONNECTIONS , ARTIFICIAL INTELLIGENCE , NETWORK FLOWS


Subject Categories : Computer Programming and Software


Distribution Statement : APPROVED FOR PUBLIC RELEASE