The measure algebra does not always embed
The Open Colouring Axiom implies that the measure algebra cannot be embedded into P(ℕ)/fin. We also discuss errors in previous results on the embeddability of the measure algebra.
The Nikodym property and local properties of Boolean algebras
We study local interpolation properties and local supremum properties for a Boolean algebra. In particular, we present a new condition that is sufficient for the Nikodym property.
The number of countable isomorphism types of complete extensions of the theory of Boolean algebras
There is a conjecture of Vaught [17] which states: Without The Generalized Continuum Hypothesis one can prove the existence of a complete theory with exactly nonisomorphic, denumerable models. In this paper we show that there is no such theory in the class of complete extensions of the theory of Boolean algebras. More precisely, any complete extension of the theory of Boolean algebras has either 1 or nonisomorphic, countable models. Thus we answer this conjecture in the negative for any complete...
The rings which are Boolean
We study unitary rings of characteristic 2 satisfying identity for some natural number p. We characterize several infinite families of these rings which are Boolean, i.e., every element is idempotent. For example, it is in the case if or or for a suitable natural number n. Some other (more general) cases are solved for p expressed in the form or where q is a natural number and .
The rings which are Boolean. II.
The Rings Which Can Be Recovered by Means of the Difference
It is well known that to every Boolean ring can be assigned a Boolean algebra whose operations are term operations of . Then a symmetric difference of together with the meet operation recover the original ring operations of . The aim of this paper is to show for what a ring a similar construction is possible. Of course, we do not construct a Boolean algebra but only so-called lattice-like structure which was introduced and treated by the authors in a previous paper. In particular, we reached...
The semigroup of circulant Boolean matrices
The sequential topology on complete Boolean algebras
We investigate the sequential topology on a complete Boolean algebra B determined by algebraically convergent sequences in B. We show the role of weak distributivity of B in separation axioms for the sequential topology. The main result is that a necessary and sufficient condition for B to carry a strictly positive Maharam submeasure is that B is ccc and that the space is Hausdorff. We also characterize sequential cardinals.
The space of ultrafilters on N covered by nowhere dense sets
The spectral test of the Boolean function linearity
The paper discusses the problem of recognizing the Boolean function linearity. A spectral method of the analysis of Boolean functions using the Walsh transform is described. Linearity and nonlinearity play important roles in the design of digital circuits. The analysis of the distribution of spectral coefficients allows us to determine various combinatorial properties of Boolean functions, such as redundancy, monotonicity, self-duality, correcting capability, etc., which seems more difficult be...
Three generators for minimal writing-space computations
Three generators for minimal writing-space computations
We construct, for each integer n, three functions from {0,1}n to {0,1} such that any boolean mapping from {0,1}n to {0,1}n can be computed with a finite sequence of assignations only using the n input variables and those three functions.
Torsion classes of Specker lattice ordered groups
In this paper we investigate the relations between torsion classes of Specker lattice ordered groups and torsion classes of generalized Boolean algebras.
Totally disconnected compactifications.
Triangular solutions of Boolean equations.
Two constructions of De Morgan algebras and De Morgan quasirings
De Morgan quasirings are connected to De Morgan algebras in the same way as Boolean rings are connected to Boolean algebras. The aim of the paper is to establish a common axiom system for both De Morgan quasirings and De Morgan algebras and to show how an interval of a De Morgan algebra (or De Morgan quasiring) can be viewed as a De Morgan algebra (or De Morgan quasiring, respectively).
Two elementary commutativity theorems for generalized Boolean rings.
Two properties of free Boolean algebras
Two theorems of functional analysis effectively equivalent to choice axioms
Über gewisse Sätze vom Foulis-Holland-Typ in Boole'schen Zwerchverbänden.