On Syntactically Similar Logic Programs and Sequential Decompositions

Sequential and Parallel Iteration in Logic Programs

Iterative programs are more elegant than their recursive counterparts for many problems and can be executed more eeciently than recursive programs run in the usual way on sequential computers. Moreover, they can often be executed with low overhead on parallel computers. We propose to employ bounded quantiications as an explicit iteration construct for Prolog programs and show that they do run e...

Syntactically Recognizable Modularly Stratified Programs

We present an eecient evaluation technique for modularly stratiied programs for which the local strata level mappings are known at compile time. We present an important subclass of these programs (called EMS-programs) in which one can easily express problems such as shortest distance, company ownership, bill of materials, preferential vote counting, and matrix diagonalization. Programs written ...

Tree-decompositions and logic

Tree-width is a parameter that measures the similarity of a graph or relational structure with a tree. Many NP-hard decision and optimization problems are solvable in polynomial time on classes of bounded tree-width. A general theorem due to Courcelle states that this is the case for all problems that are definable in monadic second-order logic. In this talk we will introduce the concept of tre...

Comparing the Expressive Powers of Some Syntactically Restricted Classes of Logic Programs

On Bi-Decompositions of Logic Functions

A logic function f has a disjoint bi-decomposition i f can be represented as f = h(g1(X1); g2(X2)), where X1 and X2 are disjoint set of variables, and h is an arbitrary two-variable logic fuction. f has a non-disjoint bidecomposition i f can be represented as f(X1;X2; x) = h(g1(X1; x); g2(X2; x)), where x is the common variable. In this paper, we show a fast method to nd bidecompositions. Also,...