The reasonable choice is a critical success factor for decision- making in the field of software engineering (SE). A case-driven comparative analysis has been introduced and a procedure for its systematic application has been suggested. The paper describes how the proposed method can be built in a general framework for SE activities. Some examples of experimental versions of the framework are brie y presented.
Many approaches such as component technologies have been invented in order to support software reuse. Based on these technologies a large variety of techniques have been introduced to connect components. However, there is little experience concerning the validation of component systems. We know how to plug components together, but we do need ways to check whether that works. In this paper we introduce an approach to validating component compositions and showing how such a process can be supported...
The logic of signed formula can be used to reason about a wide variety of multiple-valued logics [Häh94b, LMR97]. The formal theoretical foundation of multiple-valued logic programming based on signed formulas is set forth in [Lu96]. The current paper is an investigation into the operational semantics of such signed logic programming. The connection of signed logic programming to constraint logic programming is presented, search space issues are briefly discussed for both general and special cases,...
Object oriented design has proven itself as a powerful tool in the field of scientific computing. Several software packages, libraries and toolkits exist, in particular in the FEM arena that follow this design methodology providing extensible, reusable, and flexible software while staying competitive to traditionally designed point tools in terms of efficiency. However, the common approach to identify classes is to turn data structures and algorithms of traditional implementations into classes such...
Object oriented design has proven itself as a powerful tool in the field of scientific computing. Several software packages, libraries and toolkits exist, in particular in the FEM arena that follow this design methodology providing extensible, reusable, and flexible software while staying competitive to traditionally designed point tools in terms of efficiency. However, the common approach to identify classes is to turn data structures and algorithms of traditional implementations into ...
A new implementation concept for parameterized specifications based on constructors and abstractors was recently introduced by Orejas, Navarro and Sánchez which includes most of the implementation concepts in the literature for initial as well as loose semantics. In this paper we redefine vertical and different kinds of horizontal compositions using the new concept of semi-pushout defined for a mixture of signature and specification morphisms. The main results concerning correctness of horizontal...
Various static analyses of functional programming languages that permit infinite data structures make use of set constants like Top, Inf, and Bot, denoting all terms, all lists not eventually ending in Nil, and all non-terminating programs, respectively. We use a set language that permits union, constructors and recursive definition of set constants with a greatest fixpoint semantics in the set of all, also infinite, computable trees, where all term constructors are non-strict. This...
In this paper we argue that for fuzzy unification we need a procedural and declarative semantics (as opposed to the two valued case, where declarative semantics is hidden in the requirement that unified terms are syntactically – letter by letter – identical). We present an extension of the syntactic model of unification to allow near matches, defined using a similarity relation. We work in Hájek’s fuzzy logic in narrow sense. We base our semantics on a formal model of fuzzy logic programming extended...
This text includes the definition and basic notions of product of posets, chain-complete and flat posets, flattening operation, and the existence theorems of recursive call using the flattening operator. First part of the article, devoted to product and flat posets has a purely mathematical quality. Definition 3 allows to construct a flat poset from arbitrary non-empty set [12] in order to provide formal apparatus which eanbles to work with recursive calls within the Mizar langauge. To achieve this...
We show that the standard normalization-by-evaluation construction for the simply-typed -calculus has a natural counterpart for the untyped -calculus, with the central type-indexed logical relation replaced by a “recursively defined” invariant relation, in the style of Pitts. In fact, the construction can be seen as generalizing a computational-adequacy argument for an untyped, call-by-name language to normalization instead of evaluation.In the untyped setting, not all terms have normal forms,...
We show that the standard normalization-by-evaluation construction for the simply-typed λβη-calculus has a natural counterpart for the untyped λβ-calculus, with the central type-indexed logical relation replaced by a “recursively defined” invariant relation, in the style of Pitts. In fact, the construction can be seen as generalizing a computational-adequacy argument for an untyped, call-by-name language to normalization instead of evaluation.In the untyped setting, not all terms have normal...