16 research outputs found
Introduction to the 28th International Conference on Logic Programming Special Issue
We are proud to introduce this special issue of the Journal of Theory and
Practice of Logic Programming (TPLP), dedicated to the full papers accepted for
the 28th International Conference on Logic Programming (ICLP). The ICLP
meetings started in Marseille in 1982 and since then constitute the main venue
for presenting and discussing work in the area of logic programming
Breaking Symmetries in Graph Representation
There are many complex combinatorial problems
which involve searching for an undirected graph
satisfying a certain property. These problems are
often highly challenging because of the large number
of isomorphic representations of a possible solution.
In this paper we introduce novel, effective
and compact, symmetry breaking constraints for
undirected graph search. While incomplete, these
prove highly beneficial in pruning the search for a
graph. We illustrate the application of symmetry
breaking in graph representation to resolve several
open instances in extremal graph theory
Redundant Sudoku Rules
The rules of Sudoku are often specified using twenty seven
\texttt{all\_different} constraints, referred to as the {\em big} \mrules.
Using graphical proofs and exploratory logic programming, the following main
and new result is obtained: many subsets of six of these big \mrules are
redundant (i.e., they are entailed by the remaining twenty one \mrules), and
six is maximal (i.e., removing more than six \mrules is not possible while
maintaining equivalence). The corresponding result for binary inequality
constraints, referred to as the {\em small} \mrules, is stated as a conjecture.Comment: 14 pages, 161 figures, to appear in TPL