This paper studies the problem of perfectly secure communication in general network in
which processors and communication lines may be faulty. Lower bounds are obtained on …

This paper studies the complexity of determining if a finite algebra generates a variety that
satisfies various Maltsev conditions, such as congruence distributivity or modularity. For …

The clone of term operations of an algebraic structure consists of all operations that can be
expressed by a term in the language of the structure. We consider bounds for the length and …

One of the important classes of varieties identified in tame congruence theory is the class of
varieties which are-permutable for some. In this paper, we prove two results:(1) for every …

In this paper we consider the complexity of several problems involving finite algebraic
structures. Given finite algebras A and B, these problems ask the following.(1) Do A and B …

Theoretical Computer Science A finite set of functions with an EXPTIME-complete composition
problem Page 1 Theoretical Computer Science 407 (2008) 330–341 Contents lists available at …

We exhibit finite algebras each generating a variety with NP-complete finite algebra
membership problem. The smallest of these algebras is the flat graph algebra belonging to …

This paper examines the computational complexity of determining whether or not an algebra
satisfies a certain Mal'Cev condition. First, we define a class of Mal'Cev conditions whose …

We prove that the problem of determining whether a finite logical matrix determines an
algebraizable logic is complete for EXPTIME. The same result holds for the classes of order …

We discuss the computational complexity of several problems concerning subsets of an
algebraic structure that generate the structure. We show that the problem of determining …