scholarly journals An Abstract Contract Theory for Programs with Procedures

2021 ◽  
pp. 152-171
Author(s):  
Christian Lidström ◽  
Dilian Gurov
Keyword(s):  
Programming Languages ◽  
Contract Theory ◽  
Denotational Semantics ◽  
The Other ◽  
Hoare Logic ◽  
Basic Building Block ◽  
Sequential Programming ◽  
Modular Verification ◽  
The One ◽  
Meta Theory

AbstractWhen developing complex software and systems, contracts provide a means for controlling the complexity by dividing the responsibilities among the components of the system in a hierarchical fashion. In specific application areas, dedicated contract theories formalise the notion of contract and the operations on contracts in a manner that supports best the development of systems in that area. At the other end, contract meta-theories attempt to provide a systematic view on the various contract theories by axiomatising their desired properties. However, there exists a noticeable gap between the most well-known contract meta-theory of Benveniste et al. [5], which focuses on the design of embedded and cyber-physical systems, and the established way of using contracts when developing general software, following Meyer’s design-by-contract methodology [18]. At the core of this gap appears to be the notion of procedure: while it is a central unit of composition in software development, the meta-theory does not suggest an obvious way of treating procedures as components.In this paper, we provide a first step towards a contract theory that takes procedures as the basic building block, and is at the same time an instantiation of the meta-theory. To this end, we propose an abstract contract theory for sequential programming languages with procedures, based on denotational semantics. We show that, on the one hand, the specification of contracts of procedures in Hoare logic, and their procedure-modular verification, can be cast naturally in the framework of our abstract contract theory. On the other hand, we also show our contract theory to fulfil the axioms of the meta-theory. In this way, we give further evidence for the utility of the meta-theory, and prepare the ground for combining our instantiation with other, already existing instantiations.

A PDL APPROACH FOR QUALITATIVE VELOCITY

2011 ◽  
Vol 19 (01) ◽  
pp. 11-26 ◽  
Author(s):  
A. BURRIEZA ◽  
E. MUÑOZ-VELASCO ◽  
M. OJEDA-ACIEGO
Keyword(s):  
Programming Languages ◽  
Moving Objects ◽  
Spatial Reasoning ◽  
Axiom System ◽  
Qualitative Reasoning ◽  
The Other ◽  
Other Hand ◽  
Order Of Magnitude ◽  
The One ◽  
Different Levels

We introduce the syntax, semantics, and an axiom system for a PDL-based extension of the logic for order of magnitude qualitative reasoning, developed in order to deal with the concept of qualitative velocity, which together with qualitative distance and orientation, are important notions in order to represent spatial reasoning for moving objects, such as robots. The main advantages of using a PDL-based approach are, on the one hand, all the well-known advantages of using logic in AI, and, on the other hand, the possibility of constructing complex relations from simpler ones, the flexibility for using different levels of granularity, its possible extension by adding other spatial components, and the use of a language close to programming languages.

Language Games

2014 ◽  
Author(s):  
Subrata Dasgupta
Keyword(s):  
Programming Languages ◽  
The United States ◽  
Point Of View ◽  
The Other ◽  
Language Games ◽  
Von Neumann ◽  
Noam Chomsky ◽  
Computer Scientists ◽  
The One ◽  
Abstract Artifacts

It must have been entirely coincidental that two remarkable linguistic movements both occurred during the mid 1950s—one in the realm of natural language, the other in the domain of the artificial; the one brought about largely by a young linguist named Noam Chomsky (1928–), the other initiated by a new breed of scientists whom we may call language designers; the one affecting linguistics so strongly that it would be deemed a scientific revolution, the other creating a class of abstract artifacts called programming languages and also enlarging quite dramatically the emerging paradigm that would later be called computer science. As we will see, these two linguistic movements intersected in a curious sort of way. In particular, we will see how an aspect of Chomskyan linguistics influenced computer scientists far more profoundly than it influenced linguists. But first things first: concerning the nature of the class of abstract artifacts called programming languages. There is no doubt that those who were embroiled in the design of the earliest programmable computers also meditated on a certain goal: to make the task of programming a computer as natural as possible from the human point of view. Stepping back a century, we recall that Ada, Countess of Lovelace specified the computation of Bernoulli numbers in an abstract notation far removed from the gears, levers, ratchets, and cams of the Analytical Engine (see Chapter 2, Section VIII ). We have seen in the works of Herman Goldstine and John von Neumann in the United States, and David Wheeler in England that, even as the first stored-program computers were coming into being, eff orts were being made to achieve the goal just mentioned. Indeed, a more precise statement of this goal was in evidence: to compose computer programs in a more abstract form than in the machine’s “native” language. The challenge here was twofold: to describe the program (or algorithm) in such a language that other humans could comprehend, without knowing much about the computer for which the program was written—in other words, a language that allowed communication between the writer of the program and other (human) readers—and also to communicate the program to the machine in such fashion that the latter could execute the program with minimal human intervention.

scholarly journals The Impact of the Lambda Calculus in Logic and Computer Science

1997 ◽  
Vol 3 (2) ◽  
pp. 181-215 ◽  
Author(s):  
Henk Barendregt
Keyword(s):  
Computer Science ◽  
Programming Languages ◽  
Functional Programming ◽  
Lambda Calculus ◽  
The Other ◽  
Functional Programming Languages ◽  
Other Hand ◽  
The One ◽  
The Impact

AbstractOne of the most important contributions of A. Church to logic is his invention of the lambda calculus. We present the genesis of this theory and its two major areas of application: the representation of computations and the resulting functional programming languages on the one hand and the representation of reasoning and the resulting systems of computer mathematics on the other hand.

Impartiality

1978 ◽  
Vol 8 (4) ◽  
pp. 715-724
Author(s):  
M. C. Henberg
Keyword(s):  
Contract Theory ◽  
Social Institutions ◽  
Ideal Observer ◽  
The Other ◽  
Social Benefits ◽  
Large Measure ◽  
Veil Of Ignorance ◽  
Philosophical Consideration ◽  
The Veil ◽  
The One

A great deal of philosophical consideration has been given in recent years to the issue of justice. In large measure this effort has focused upon justice in . relation to social institutions, to the distributive question of disbursing social benefits on the one hand or punishments and burdens on the other hand. Essentially we may view justice as having two basic requirements. In the first place we need conditions assuring impartial treatment of individuals and, in the second place, conditions for reasonable treatment of individuals — as injustice may arise either if relevantly similar persons are accorded dissimilar treatment or if they receive similar but unreasonable treatment.In this article I shall examine a number of devices which have been proposed to meet the first requirement — that of impartiality. Social theorists have pursued impartiality with strategies ranging from the disinterested Ideal Observer of many utilitarians to the ‘veil of ignorance’ conditions in John Rawls's revitalized contract theory. I shall demonstrate that the preoccupation with impartiality in social institututions has had an unfortunate consequence. It has obscured the original motive for impartiality and led to a misunderstanding of the concept.

scholarly journals AutoParallel: Automatic parallelisation and distributed execution of affine loop nests in Python

2020 ◽  
Vol 34 (6) ◽  
pp. 659-675
Author(s):  
Cristian Ramon-Cortes ◽  
Ramon Amela ◽  
Jorge Ejarque ◽  
Philippe Clauss ◽  
Rosa M. Badia
Keyword(s):  
Programming Languages ◽  
Scale Up ◽  
Distributed Applications ◽  
Loop Nests ◽  
Sequential Programming ◽  
Distributed Execution ◽  
One Step ◽  
The One ◽  
Blocked Algorithms ◽  
Distributed And Parallel Computing

The last improvements in programming languages and models have focused on simplicity and abstraction; leading Python to the top of the list of the programming languages. However, there is still room for improvement when preventing users from dealing directly with distributed and parallel computing issues. This paper proposes and evaluates AutoParallel, a Python module to automatically find an appropriate task-based parallelisation of affine loop nests and execute them in parallel in a distributed computing infrastructure. It is based on sequential programming and contains one single annotation (in the form of a Python decorator) so that anyone with intermediate-level programming skills can scale up an application to hundreds of cores. The evaluation demonstrates that AutoParallel goes one step further in easing the development of distributed applications. On the one hand, the programmability evaluation highlights the benefits of using a single Python decorator instead of manually annotating each task and its parameters or, even worse, having to develop the parallel code explicitly (e.g., using OpenMP, MPI). On the other hand, the performance evaluation demonstrates that AutoParallel is capable of automatically generating task-based workflows from sequential Python code while achieving the same performances than manually taskified versions of established state-of-the-art algorithms (i.e., Cholesky, LU, and QR decompositions). Finally, AutoParallel is also capable of automatically building data blocks to increase the tasks’ granularity; freeing the user from creating the data chunks, and re-designing the algorithm. For advanced users, we believe that this feature can be useful as a baseline to design blocked algorithms.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

Radioimmunotherapy for treatment of acute myeloid leukaemia and myelodysplastic syndrome

2005 ◽  
Vol 44 (03) ◽  
pp. 107-117
Author(s):  
R. G. Meyer ◽  
W. Herr ◽  
A. Helisch ◽  
P. Bartenstein ◽  
I. Buchmann
Keyword(s):  
Acute Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
Primary Tumour ◽  
The Other ◽  
Haematopoietic Stem Cell ◽  
Other Hand ◽  
Primary Reduction ◽  
The One ◽  
Acute Myeloid

SummaryThe prognosis of patients with acute myeloid leukaemia (AML) has improved considerably by introduction of aggressive consolidation chemotherapy and haematopoietic stem cell transplantation (SCT). Nevertheless, only 20-30% of patients with AML achieve long-term diseasefree survival after SCT. The most common cause of treatment failure is relapse. Additionally, mortality rates are significantly increased by therapy-related causes such as toxicity of chemotherapy and complications of SCT. Including radioimmunotherapies in the treatment of AML and myelodyplastic syndrome (MDS) allows for the achievement of a pronounced antileukaemic effect for the reduction of relapse rates on the one hand. On the other hand, no increase of acute toxicity and later complications should be induced. These effects are important for the primary reduction of tumour cells as well as for the myeloablative conditioning before SCT.This paper provides a systematic and critical review of the currently used radionuclides and immunoconjugates for the treatment of AML and MDS and summarizes the literature on primary tumour cell reductive radioimmunotherapies on the one hand and conditioning radioimmunotherapies before SCT on the other hand.

Das Ende der Postdemokratie, den Pessimismus überwinden.

2017 ◽  
Vol 47 (188) ◽  
pp. 487-494
Author(s):  
Daniel Mullis
Keyword(s):  
Political Thought ◽  
Social Dynamics ◽  
Social Conditions ◽  
The Other ◽  
Economic Decline ◽  
Far Right ◽  
Windows Of Opportunity ◽  
Political Events ◽  
Political Struggles ◽  
The One

In recent years, political and social conditions have changed dramatically. Many analyses help to capture these dynamics. However, they produce political pessimism: on the one hand there is the image of regression and on the other, a direct link is made between socio-economic decline and the rise of the far-right. To counter these aspects, this article argues that current political events are to be understood less as ‘regression’ but rather as a moment of movement and the return of deep political struggles. Referring to Jacques Ranciere’s political thought, the current conditions can be captured as the ‘end of post-democracy’. This approach changes the perspective on current social dynamics in a productive way. It allows for an emphasis on movement and the recognition of the windows of opportunity for emancipatory struggles.

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