|
Bry, François
(1989):
Logic Programming as Constructivism. A Formalization and its Application to Databases.
Symposium on Principles of Database Systems, 29.03.-31.03.1989, Philadelphia, Pennslyvania.
|
![[img]](http://epub.ub.uni-muenchen.de/8502/1.hassmallThumbnailVersion/8502.pdf)  Preview |
|
PDF
2642Kb |
Abstract
The features of logic programming that
seem unconventional from the viewpoint of classical logic
can be explained in terms of constructivistic logic. We
motivate and propose a constructivistic proof theory of
non-Horn logic programming. Then, we apply this formalization
for establishing results of practical interest.
First, we show that 'stratification can be motivated in a
simple and intuitive way. Relying on similar motivations,
we introduce the larger classes of 'loosely stratified' and
'constructively consistent' programs. Second, we give a
formal basis for introducing quantifiers into queries and
logic programs by defining 'constructively domain
independent* formulas. Third, we extend the Generalized
Magic Sets procedure to loosely stratified and constructively
consistent programs, by relying on a 'conditional
fixpoini procedure.