A method of construction an inverse system finite compacta, indexed with positive reals, from a compact ultrapseudometric, is proposed. It proved that homeomorphisms and natural preorder on the class ultrapseudometrics correspond to strict isomorphisms morphisms respective systems. Properties poset obtained "gluing together" isomorphic systems, are discussed.

We give a new description of the fundamental double four-spiral semigroup. The fundamental four-spiral semigroup Sp4 and the fundamental double fourspiral semigroup DSp4 were introduced in [1], [3], and [4]. These semigroups are interesting examples of fundamental regular semigroups, and are indispensable building blocks of bisimple, idempotent-generated regular semigroups. Their basic properti...

We provide a finite basis for the (in)equational theory of the process algebra BCCS modulo the weak failures preorder and equivalence. We also give positive and negative results regarding the axiomatizability of BCCS modulo weak impossible futures semantics.

In this paper, we investigate the properties of Alexandrov fuzzy topologies and join-meet approximation operators. We study fuzzy preorder, Alexandrov topologies join-meet approximation operators induced by Alexandrov fuzzy topologies. We give their examples.

This paper addresses the problem of deening a formal tool to compare the expressive power of diierent concurrent constraint languages. We reene the notion of embedding by adding some \reasonable" conditions, suitable for concurrent frameworks. The new notion, called modular embedding, is used to deene a preorder among these languages, representing diierent degrees of expressiveness. We show tha...

Abstract Real-time applications such as streaming media and voice require encryption algorithms that do not propagate errors and support fast encryption on small blocks. Since IP packets are delivered out-of-order in routed networks it is difficult to synchronize the source and the destination, therefore requiring encryption algorithms to support out-of-order generation of key stream. In this p...

This paper presents the Logical Process Calculus (LPC), a formalism that supports heterogeneous system specifications containing both operational and declarative subspecifications. Syntactically, kPC extends Milner's Calculus of Conmmnicating Systems with operators fl'om the alternation free linear time p calculus (kT#). Semantically, kPC is equipped with a behavioral preorder that generalizes ...

We introduce a notion of real-valued reward testing for probabilistic processes by extending the traditional nonnegative-reward testing with negative rewards. In this richer testing framework, the may and must preorders turn out to be inverses. We show that for convergent processes with finitely many states and transitions, but not in the presence of divergence, the real-reward must-testing pre...

In a previous paper [10] we explored the notion of coherent fuzzy consequence operator. It is well-known that the operator induced by a fuzzy preorder through Zadeh’s compositional rule is always a coherent fuzzy consequence operator. It is also known that the relation induced by a fuzzy consequence operator is a fuzzy preorder if such operator is coherent [7]. Fuzzy closing operators of mathem...