Antoni Kreczmar

Effectivity Problems of Algorithmic Logic

The subject we consider in the present paper is recently very fashionable. We shall deal with effectivity problems such as recursiveness, degrees of unsolvability and arithmetical classes of notions investigated in the theory of programming. In opposition to many previous publications we shall try to show these problems can be solved in a uniform way due to an appropriate choice of formal language and application of its own metamathematical methods.

Semantics and implementation of prefixing at many levels

A generalization of Simulas prefixing of classes is presented. The notion of one-level prefixing is first introduced by means of the example of Simula 67; the semantics of a programming language with prefixing at many levels is then discussed and analyzed.

On memory requirements of Strassen's algorithms

In the paper we analyse the memory problem of Strassens algorithms for fast matrix multiplication and inversion.

Modules in high level programming languages

Publisher Summary An average user appreciates a programming language looking at the easiness of programming, which depends mainly on its expressive power and its security. Generally, it is not necessary to understand even what the implementation of a programming language is. However, experienced programmers know quite well that without a deeper knowledge of some implementation aspects, the real software would never exist. This chapter discusses the kinds of programming languages; the module structure of a program; the blocks, procedures, and functions of a program; the cooperation of coroutines, coroutine sequencing, and the different passing modes of parameters. Some high level programming languages, like ALGOL 60, PL/1 and Pascal, allow procedures and functions as parameters, that is, they admit formal procedure construct. This important construct is easy in use; however, the precise semantics needs some deeper insight. One of the most important characteristics of classes is the possibility of defining abstract data types. An important feature that extends the power and the flexibility of classes is inheritance rule [CURR], [ING], [MEY], sometimes called prefixing [SIM]. Inheritance is a method for module extending by some new specifications and actions that are added to the previous ones. It can be said that such a module inherits all the properties of its parent module.

On Finite and Infinite Computations

In the present paper we shall try to characterize the properties of programmable functions and relations over some relational structures. The structures which constitute the major part of our investigations are the fields of real and complex numbers. We shall deal with some general questions concerning the elimination of while-statements. It will be shown that this elimination is possible for a wide class of programs over fields which satisfy a certain algebraic condition.

On inheritance rule in object oriented programming

Publisher Summary Object oriented programming (OOP) bases on the notion of a class. Class is a category of modules that syntactically looks like a procedure, that is, it has its name, may have parameters, may have local declarations, may have the sequence of statements etc. However, additionally, class can be used as a pattern in generation as many as needed instances and that these instances are not automatically de-allocated after the termination of their sequence of statements. Usually, such instances are called objects. The simplest kind of a syntactic category in programming languages that deals with something like object is a pointer type of Pascal. All OOP languages admit inheritance rule. In Simula-67, this notion was called prefixing because of the Simula syntax; however, the term inheritance is more adequate and widely used. This chapter describes the importance of nesting and inheritance constructs in OOP. Nesting is the essence of high level imperative programming. Its importance is undisputable. The nesting of classes is also of great importance. The real practical applications prove that unlimited nesting is necessary in secure and efficient programming. Inheritance is the essence of OOP. It enables to create the hierarchies of classes.

Concatenation of program modules an algebraic approach to the semantic and implementation problems

The paper studies the semantic and implementation problems of programming languages which allow module concatenation. Three known languages of that class are Simula-67, Smalltalk and Loglan. The structure of program modules is treated as an algebra. A concise set of algebraic axioms defining this structure is given. The addressing problem is formulated in algebraic terms. The identifier binding rule is reduced to the evaluation of terms in the algebra of modules. The normal form theorem solves the question of this evaluation. The results allow to develop two efficient updating algorithms going beyond standard Dijkstras algorithm and relevant for this class of languages. The paper ends with the detailed implementation techniques. The correctness of this implementation is proved. All of this allow to construct a new family of running-systems for languages with module concatenation.