A fixed-point free involution on a finite set S is defined as a bijection I : S S such as e S, I(I(e)) = e and e S, I(e) = e. In this article, the fixed-point free involutions ...
Given S1, a finite set of points in the plane, we define a sequence of point sets Si as follows: With Si already determined, let Li be the set of all the line segments connecting ...
We propose and study extensions of logic programming with constraints represented as generalized atoms of the form C(X), where X is a finite set of atoms and C is act constraint (...
We prove that any finite set of half-planes can be colored by two colors so that every point of the plane, which belongs to at least three half-planes in the set, is covered by ha...
Schema mappings are high-level specifications that describe the relationship between two database schemas; they are considered to be the essential building blocks in data exchange...
The reconstruction of a shape or surface from a finite set of points is a practically significant and theoretically challenging problem. This paper presents a unified view of algor...
The growth and operation of all living beings are directed by the interpretation, in each of their cells, of a chemical program, the DNA string or genome. This process is the sour...