In this note, by means of the spectrum of the generating operator, we characterize the self-adjointness and closedness of the range of a normal and a self-adjoint Jordan *-derivation, respectively.

There are numerous occasions on which we need to reason about a finite number of events. And we often need to consider only those events which are given or which we perceive. These give rise to the Criteria of Finiteness and Closedness. Allen’s logic provides a way of reasoning about events. In this paper I examine Allen and Hayes’ axiomatisation of this logic, and develop two other axiomatisat...

A new class of weak weighted derivatives and its associated Sobolev spaces is introduced and studied. The proposed notion uses a variational formulation in its definition which generalizes the usual weighting of the classical weak derivative. Such a construction naturally leads to Sobolev spaces containing classes of discontinuous functions. Weak closedness with respect to both varying function...

The article addresses the relationship between open and closed texts. aim of study is to analyze specifics text in general context communication author reader. While supporting mainly U. Eco’s concept our article, we furnish it with analysis four approaches openness/closedness, which have singled out. Openness/closedness conceptualized, firstly: as an ontological perspective opposition paramete...

Let Dn be the unit polydisc of Cn. The class of all holomorphic functions with domain Dn will be denoted by H(Dn). Let φ be a holomorphic self-map of Dn, the composition operator Cφ induced by φ is defined by (Cφ f )(z) = f (φ(z)) for z ∈Dn and f ∈H(Dn). If, in addition, ψ is a holomorphic function defined on Dn, the weighted composition operator ψCφ induced by ψ and φ is defined by ψCφ(z) = ψ(...

An Object-Z formal speci cation of the ODP Trader is presented which concisely captures the hierarchical context structure, the distribution of information and the communication aspects of the Trader. Particular use is made of generic classes, class inheritance and object aggregation (i.e. the instantiation of collections of similar objects) to give a structured speci cation that can be readily...