When a semi-formal language (like UML-RT) and a formal specification language (like CSP+T) are combined to obtain a Real-Time System (RTS) software specification, it is important to ensure the possibility of verifying the derived system design. A formal semantics of CSP+T temporal operators in terms of CSP trace semantics is presented here, and also a compositional refinement of CSP+T process t...

The aim of this note is to study the submajorization inequalities for $tau$-measurable operators in a semi-finite von Neumann algebra on a Hilbert space with a normal faithful semi-finite trace $tau$. The submajorization inequalities generalize some results due to Zhang, Furuichi and Lin, etc..

In this paper, we introduce a generalization of Hilbert $C^*$-modules which are pre-Finsler modules, namely, $C^{*}$-semi-inner product spaces. Some properties and results of such spaces are investigated, specially the orthogonality in these spaces will be considered. We then study bounded linear operators on $C^{*}$-semi-inner product spaces.

We discuss the concept of what we refer to as semi-commuting linear differential operators. Such operators hold commuting operators as a special case. In particular, we discuss a heuristic by which one may construct such operators. Restricting to the case in which one such operator is of degree two, we construct families of linear differential operators semi-commuting with some named operators ...

Abstract Approximation fixpoint theory (AFT) is an abstract and general algebraic framework for studying the semantics of non-monotonic logics. In recent work, AFT was generalized to non-deterministic operators, that is, operators whose range are sets elements rather than single elements. this paper, we make three further contributions AFT: (1) define study ultimate approximations (2) give form...

Certain norm-related functions have been considered in order to obtain characterisations and perturbation results for various classes of semi-Fredholm-type operators. In the §2, by means of what we have called a perturbation function, we present a general approach to the question of obtaining characterisations and perturbation theorems for F + and strictly singular operators. To this end, for e...

We introduce and study some operational quantities associated to a space ideal A. These quantities are used to define generalized semi-Fredholm operators associated to A, and the corresponding perturbation classes which extend the strictly singular and strictly cosingular operators, and we study the generalized Fredholm theory obtained in this way. Finally we present some examples and show that...

We study point and higher symmetries for the hydrodynamic-type systems with two independent variables t and x with and without explicit dependence of the equations on t, x. We consider those systems which possess an infinite group of the hy-drodynamic symmetries, establish existence conditions for this property and, using it, derive linearizing transformations for these systems. The recursion o...