Characterizations of semisimple classes

New characterizations of h-semisimple hemirings

In this paper, the concept of (∈γ ,∈γ ∨qδ)-fuzzy soft hinterior ideals over a hemiring is introduced and investigated. Some characterization theorems of h-semisimple hemirings are derived in terms of (∈γ ,∈γ ∨qδ)-fuzzy soft left (right) h-ideals and (∈γ ,∈γ ∨qδ)-fuzzy soft hinterior ideals. 2010 AMS Classification: 20M12, 08A72

Logical Characterizations of Complexity Classes

Syntactic Characterizations of Polynomial Time Optimization Classes

The characterization of important complexity classes by logical descriptions has been an important and prolific area of Descriptive complexity. However, the central focus of the research has been the study of classes like P, NP, L and NL, corresponding to decision problems (e.g. the characterization of NP by Fagin [5] and of P by Grädel [7]). In contrast, optimization problems have received muc...

On forbidden subdivision characterizations of graph classes

We provide a characterization of several graph parameters (the acyclic chromatic number, the arrangeability, and a sequence of parameters related to the expansion of a graph) in terms of forbidden subdivisions. Let us start with several definitions. Throughout the paper, we consider only simple undirected graphs. A graph G = sdt(G) is the t-subdivision of a graph G, if G is obtained from G by r...

Characterizations of Logarithmic Advice Complexity Classes

The complexity classes P=log and Full-P=log, corresponding to the two standard forms of logarithmic advice for polynomial time, are studied. The novel proof technique of \doubly exponential skip" is introduced, and characterizations for these classes are found in terms of several other concepts, among them easy-to-describe boolean circuits and reduction classes of tally sets with high regularit...