Jacek Leszczylowski

Updatable XML Views

XML views can be used in Web applications to resolve incompatibilities among heterogeneous XML sources. They allow to reduce the amount of data that a user has to deal with and to customize an XML source. We consider virtual updatable views for a query language addressing an XML native database. The novelty of the presented mechanism is inclusion of information about intents of updates into view definitions. This information takes the form of procedures that overload generic view updating operations. The mechanism requires integration of queries with imperative (procedural) statements and with procedures. This integration is possible within the Stack-Based Approach to query languages, which is based on the classical concepts of programming languages such as the environment stack and the paradigm of naming/scop-ing/binding. In the paper, we present the view mechanism describing its syntax, semantics and discussing examples illustrating its possible applications.

A system for reasoning within and about algebraic specifications

A machine-implemented system to support the reasoning about algebraic specifications is presented. The PAT-system is an attempt to ease design, analysis, and implementation of partial abstract data types. More precisely, the PAT-system

On fundamentals of computer-aided design of firmware

A real-time model of microprogrammed hardware is described. It is used for firmware classification and for stating the conditions under which an equivalent discrete-time model can be introduced. We also give a brief description of a computer-aided firmware design system, which was based on these models.

Edingburgh LCF Supporting FP Systems

J.Backus, in CACM 21/8, defined a class of applicative programming systems called FP (functional programming) systems in which users have: (1) objects built recursively from atoms, ⊥ (an undefined element) and objects by a ⊥-preserving “list” operator, (2) elementary functions over objects, (3) tools for building functions out of already existing functions. It is an important feature of FP systems that these tools use no variables in the sense of programming languages. In fact Backus also avoided the use of variables while building the algebra of FP systems which is supposed to be a calculus to express and prove facts about the defined functions in the system.