Transformation-based bottom-up computation of the well-founded model

Transformation-Based Bottom-Up Computation Of The Well-Founded Model

Transformation-Based Bottom-Up Computation of the Well-Founded Model

We present a framework for expressing bottom-up algorithms to compute the well-founded model of non-disjunctive logic programs. Our method is based on the notion of conditional facts and elementary program transformations studied by Brass and Dix in (Brass & Dix, 1994; Brass & Dix, 1999) for disjunctive programs. However, even if we restrict their framework to nondisjunctive programs, their “re...

Transformation - Based Bottom - Up Computationof the Well - Founded

We present a bottom-up algorithm for the computation of the well-founded model of non-disjunctive logic programs. Our method is based on the elementary program transformations studied by Brass and Dix 6, 7]. However, their \residual program" can grow to exponential size, whereas for function-free programs our \program remain-der" is always polynomial in the size, i.e. the number of tuples, of t...

Well-Founded Ordered Search: Goal-Directed Bottom-Up Evaluation of Well-Founded Models

There have been several evaluation mechanisms proposed for computing query answers based on the well-founded semantics, for programs with negation. However, these techniques are costly; in particular, for the special case of modularly stratiied programs, Ordered Search is more eecient than the general purpose techniques. However, Ordered Search is applicable only to modularly stratiied programs...

Bottom-Up Evaluation and Query Optimization of Well-Founded Models

We present a bottom-up operational procedure for computing well-founded models of allowed programs with negation. This procedure provides a practical method of handling programs that involve unstratiied negation in a manner that may be mixed with other evaluation approaches, such as semi-naive evaluation and various program transformations. We deene classes of programs and sideways information ...