TY  - CONF
A1  - Seipel, Dietmar
T1  - Practical Applications of Extended Deductive Databases in DATALOG*
N2  - A wide range of additional forward chaining applications could be realized with deductive databases, if their rule formalism, their immediate consequence operator, and their fixpoint iteration process would be more flexible. Deductive databases normally represent knowledge using stratified Datalog programs with default negation. But many practical applications of forward chaining require an extensible set of user–defined built–in predicates. Moreover, they often need function symbols for building complex data structures, and the stratified fixpoint iteration has to be extended by aggregation operations. We present an new language Datalog*, which extends Datalog by stratified meta–predicates (including default negation), function symbols, and user–defined built–in predicates, which are implemented and evaluated top–down in Prolog. All predicates are subject to the same backtracking mechanism. The bottom–up fixpoint iteration can aggregate the derived facts after each iteration based on user–defined Prolog predicates.
KW  - deductive databases
KW  - Prolog
KW  - forward / backward chaining
KW  - bottom–up
KW  - top– down
KW  - built–in predicates
KW  - stratification
KW  - function symbols
KW  - XM
Y1  - 2010
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/3961
UR  - https://nbn-resolving.org/urn:nbn:de:kobv:517-opus-41457
ER  -