A Tutorial on Using Dafny to Construct Verified Software
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A Study of Computing in Education and Ways to Enhance Students’ Perceptions and Understanding of Computing
SCHOOL OF DESIGN, ENGINEERING & COMPUTING MSc Enterprise Information Systems September 2013 Computing in Education: A study of computing in education and ways to enhance students’ perceptions and understanding of computing by Paul Albinson BSc (Hons), FdSc, MBCS Page 1 of 166 Abstract There is a huge demand for computing skills in industry due to computing becoming ubiquitous and essential for modern life. Yet despite this, industry struggles to find employees with suitable computing skills and similarly Further and Higher Education institutions have observed a lack of interest in their computing courses in recent years. This study looks at possible reasons for this lack of interest in computing, how computing is taught in education and ways to improve students’ perceptions and understanding of computing. It focuses around a case study of a university outreach event for secondary schools which investigated how interactive teaching methods can be used to enhance students’ perceptions and understanding of computing and to increase their computing knowledge. It includes the use of physical computing and was designed to make computing fun, motivational and relevant, and to provide examples of real-world applications. Surveys were used before and after the event to understand what students’ impressions and knowledge of computing is and to see if the event improved these. Observations were also used to see how well the students handled the event’s content and whether they appeared to enjoy and understand it. Results from the case study indicate that interactive teaching methods enhance computing education, and physical computing with electronics can enhance lessons and show the relevance of computing with examples of real-world applications, and can be fun and motivational. -
Génération Automatique De Tests Unitaires Avec Praspel, Un Langage De Spécification Pour PHP the Art of Contract-Based Testing in PHP with Praspel
CORE Metadata, citation and similar papers at core.ac.uk Provided by HAL - Université de Franche-Comté G´en´erationautomatique de tests unitaires avec Praspel, un langage de sp´ecificationpour PHP Ivan Enderlin To cite this version: Ivan Enderlin. G´en´eration automatique de tests unitaires avec Praspel, un langage de sp´ecificationpour PHP. Informatique et langage [cs.CL]. Universit´ede Franche-Comt´e,2014. Fran¸cais. <NNT : 2014BESA2067>. <tel-01093355v2> HAL Id: tel-01093355 https://hal.inria.fr/tel-01093355v2 Submitted on 19 Oct 2016 HAL is a multi-disciplinary open access L'archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destin´eeau d´ep^otet `ala diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publi´esou non, lished or not. The documents may come from ´emanant des ´etablissements d'enseignement et de teaching and research institutions in France or recherche fran¸caisou ´etrangers,des laboratoires abroad, or from public or private research centers. publics ou priv´es. Thèse de Doctorat école doctorale sciences pour l’ingénieur et microtechniques UNIVERSITÉ DE FRANCHE-COMTÉ No X X X THÈSE présentée par Ivan Enderlin pour obtenir le Grade de Docteur de l’Université de Franche-Comté K 8 k Génération automatique de tests unitaires avec Praspel, un langage de spécification pour PHP The Art of Contract-based Testing in PHP with Praspel Spécialité Informatique Instituts Femto-ST (département DISC) et INRIA (laboratoire LORIA) Soutenue publiquement -
Assertions, Pre/Post- Conditions and Invariants
9/14/12 Assertions, pre/post- conditions and invariants Section 2.1 in Walls and Mirrors Section 4.5 Rosen Programming as a contract n Specifying what each method does q Specify it in a comment before method's header n Precondition q What is assumed to be true before the method is executed q Caller obligation n Postcondition q Specifies what will happen if the preconditions are met q Method obligation 1 9/14/12 Class Invariants n A class invariant is a condition that all objects of that class must satisfy while it can be observed by clients n What about Points in Cloud? q boundaries? q center? What is an assertion? n An assertion is a statement that says something about the state of your program n Should be true if there are no mistakes in the program //n == 1 while (n < limit) { n = 2 * n; } // what could you state here? 2 9/14/12 What is an assertion? n An assertion is a statement that says something about the state of your program n Should be true if there are no mistakes in the program //n == 1 while (n < limit) { n = 2 * n; } //n >= limit //more? What is an assertion? n An assertion is a statement that says something about the state of your program n Should be true if there are no mistakes in the program //n == 1 while (n < limit) { n = 2 * n; } //n >= limit //n is the smallest power of 2 >= limit 3 9/14/12 assert Using assert: assert n == 1; while (n < limit) { n = 2 * n; } assert n >= limit; When to use Assertions n We can use assertions to guarantee the behavior. -
SESAR JU CONSOLIDATED ANNUAL ACTIVITY REPORT 2020 Abstract
SESAR JU CONSOLIDATED ANNUAL ACTIVITY REPORT 2020 Abstract This Consolidated Annual Activity Report, established on the guidelines set forth in Communication from the Commission ref. 2020/2297, provides comprehensive information on the implementation of the agency work programme, budget, staff policy plan, and management and internal control systems in 2020. © SESAR Joint Undertaking, 2021 Reproduction of text is authorised, provided the source is acknowledged. For any use or reproduction of photos, illustrations or artworks, permission must be sought directly from the copyright holders. COPYRIGHT OF IMAGES © Airbus S.A.S. 2021, page 50; © Alexa Mat/Shutterstock.com, page 209; © Alexandra Lande/Shutterstock.com, page 215; © AlexLMX/Shutterstock.com page 177; © chainarong06/Shutterstock.com, page 220; © DG Stock/ Shutterstock.com, cover; © Diana Opryshko page 155; © Dmitry Kalinovsky/Shutterstock.com, page 56; © iStock. com/Gordon Tipene, pages 189 and 194; © iStock.com/Nordroden, page 12; © iStock.com/sharply_done, page 209; © iStock.com/sharply_done, page 18; © iStock.com/stellalevi, page 228, © lassedesignen/Shutterstock.com, page 70 © Mario Hagen/Shutterstock.com, pages 36 and 130; © Michael Penner, page 130; © NickolayV/Shutterstock. com, page 77; © Sergey Peterman/Shutterstock.com, page 10; © SESAR JU, pages 9, 15, 16, 17, 48, 49, 55,79, 86, 102,132, 134, 145, 147, 148 and 190; © SFIO CRACHO/Shutterstock.com, pages 181 and 213; © Skycolors/ Shutterstock.com, page 40; © smolaw/Shutterstock.com, page 211; © Thiago B Trevisan/Shutterstock.com, page 136; © This Is Me/Shutterstock.com, page 175; © VLADGRIN/Shutterstock.com, page 191; © Limare/Shutterstock, page 193; © Photo by Chris Smith on Unsplash, page 227 © Photo by Julien Bessede on Unsplash, page 224 © Photo by Sacha Verheij on Unsplash, page 221 © yuttana Contributor Studio/Shutterstock.com, page 66. -
Chapter 23 Three Design Principles
23 Three Design Principles Chapter 23 ContaxT / Kodax Tri-X Nunnery — Chichen Itza, Mexico Three Design Principles Learning Objectives • List the preferred characteristics of an object-oriented application architecture • State the definition of the Liskov Substitution Principle (LSP) • State the definition of Bertrand Meyer's Design by Contract (DbC) programming • Describe the close relationship between the Liskov Substitution Principle and Design by Contract • State the purpose of class invariants • State the purpose of method preconditions and postconditions • Describe the effects weakening and strengthening preconditions have on subclass behavior • Describe the effects weakening and strengthening postconditions have on subclass behavior • State the purpose and use of the Open-Closed Principle (OCP) • State the purpose and use of the Dependency Inversion Principle (DIP) • State the purpose of Code Contracts and how they are used to enforce preconditions, postconditions, and class invariants C# For Artists © 2015 Rick Miller and Pulp Free Press — All Rights Reserved 757 Introduction Chapter 23: Three Design Principles Introduction Building complex, well-behaved, object-oriented software is a difficult task for several reasons. First, simply programming in C# does not automatically make your application object-oriented. Second, the pro- cess by which you become proficient at object-oriented design and programming is characterized by expe- rience. It takes a lot of time to learn the lessons of bad software architecture design and apply those lessons learned to create good object-oriented architectures. The objective of this chapter is to help you jump-start your object-oriented architectural design efforts. I begin with a discussion of the preferred characteristics of a well-designed object-oriented architecture. -
Clangjit: Enhancing C++ with Just-In-Time Compilation
ClangJIT: Enhancing C++ with Just-in-Time Compilation Hal Finkel David Poliakoff David F. Richards Lead, Compiler Technology and Lawrence Livermore National Lawrence Livermore National Programming Languages Laboratory Laboratory Leadership Computing Facility Livermore, CA, USA Livermore, CA, USA Argonne National Laboratory [email protected] [email protected] Lemont, IL, USA [email protected] ABSTRACT body of C++ code, but critically, defer the generation and optimiza- The C++ programming language is not only a keystone of the tion of template specializations until runtime using a relatively- high-performance-computing ecosystem but has proven to be a natural extension to the core C++ programming language. successful base for portable parallel-programming frameworks. As A significant design requirement for ClangJIT is that the runtime- is well known, C++ programmers use templates to specialize al- compilation process not explicitly access the file system - only gorithms, thus allowing the compiler to generate highly-efficient loading data from the running binary is permitted - which allows code for specific parameters, data structures, and so on. This capa- for deployment within environments where file-system access is bility has been limited to those specializations that can be identi- either unavailable or prohibitively expensive. In addition, this re- fied when the application is compiled, and in many critical cases, quirement maintains the redistributibility of the binaries using the compiling all potentially-relevant specializations is not practical. JIT-compilation features (i.e., they can run on systems where the ClangJIT provides a well-integrated C++ language extension allow- source code is unavailable). For example, on large HPC deploy- ing template-based specialization to occur during program execu- ments, especially on supercomputers with distributed file systems, tion. -
Formal Specification Methods What Are Formal Methods? Objectives Of
ICS 221 Winter 2001 Formal Specification Methods What Are Formal Methods? ! Use of formal notations … Formal Specification Methods ! first-order logic, state machines, etc. ! … in software system descriptions … ! system models, constraints, specifications, designs, etc. David S. Rosenblum ! … for a broad range of effects … ICS 221 ! correctness, reliability, safety, security, etc. Winter 2001 ! … and varying levels of use ! guidance, documentation, rigor, mechanisms Formal method = specification language + formal reasoning Objectives of Formal Methods Why Use Formal Methods? ! Verification ! Formal methods have the potential to ! “Are we building the system right?” improve both software quality and development productivity ! Formal consistency between specificand (the thing being specified) and specification ! Circumvent problems in traditional practices ! Promote insight and understanding ! Validation ! Enhance early error detection ! “Are we building the right system?” ! Develop safe, reliable, secure software-intensive ! Testing for satisfaction of ultimate customer intent systems ! Documentation ! Facilitate verifiability of implementation ! Enable powerful analyses ! Communication among stakeholders ! simulation, animation, proof, execution, transformation ! Gain competitive advantage Why Choose Not to Use Desirable Properties of Formal Formal Methods? Specifications ! Emerging technology with unclear payoff ! Unambiguous ! Lack of experience and evidence of success ! Exactly one specificand (set) satisfies it ! Lack of automated -
Verification of Concurrent Programs in Dafny
Bachelor’s Degree in Informatics Engineering Computation Bachelor’s End Project Verification of Concurrent Programs in Dafny Author Jon Mediero Iturrioz 2017 Abstract This report documents the Bachelor’s End Project of Jon Mediero Iturrioz for the Bachelor in Informatics Engineering of the UPV/EHU. The project was made under the supervision of Francisca Lucio Carrasco. The project belongs to the domain of formal methods. In the project a methodology to prove the correctness of concurrent programs called Local Rely-Guarantee reasoning is analyzed. Afterwards, the methodology is implemented over Dagny automatic program verification tool, which was introduced to me in the Formal Methods for Software Devel- opments optional course of the fourth year of the bachelor. In addition to Local Rely-Guarantee reasoning, in the report Hoare logic, Separation logic and Variables as Resource logic are explained, in order to have a good foundation to understand the new methodology. Finally, the Dafny implementation is explained, and some examples are presented. i Acknowledgments First of all, I would like to thank to my supervisor, Paqui Lucio Carrasco, for all the help and orientation she has offered me during the project. Lastly, but not least, I would also like to thank my parents, who had supported me through all the stressful months while I was working in the project. iii Contents Abstracti Contentsv 1 Introduction1 1.1 Objectives..................................3 1.2 Work plan..................................3 1.3 Content...................................4 2 Foundations5 2.1 Hoare Logic.................................5 2.1.1 Assertions..............................5 2.1.2 Programming language.......................7 2.1.3 Inference rules...........................9 2.1.4 Recursion............................. -
Microsoft Small Basic
Katolickie Gimnazjum i Liceum Ogólnokształcące im. Jana Pawła II w Łodzi Microsoft Small Basic Translated by Anna Wilk (klasa 2a 2009/2010) Wstęp Small Basic i programowanie Programowanie komputerowe jest zdefiniowane jako proces tworzenia oprogramowania komputerowego używającego języki programowania. Tylko jak mówimy i rozumiemy Anglików albo Hiszpana albo Francuzów, komputery mogą zrozumieć programy napisane w pewnych językach. To tzw. języki programowania. Na początku było niewiele takich języków, były proste i zrozumiałe. Z czasem oprogramowanie i komputery stały się bardziej skomplikowane i wyszukane, więc języki programowania również musiały ewaluować. W efekcie są to trudne do zrozumienia metody programowania, szczególnie dla początkujących. Small Basic przedstawia programowanie w przyjemny, niezwykle łatwy i ciekawy sposób, usuwa bariery, by każdy mógł wkroczyć w świat programowania. Small Basic - Środowisko Zacznijmy od przedstawienia interfejsu Small Basic’a i poruszania się w nim. Po pierwszym uruchomieniu zobaczycie właśnie takie okno: Obrazek 1 To jest Small Basic Środowisko, gdzie napiszemy nasze programy. Opiszemy każdy element zaznaczony numerem. 1. Edytor(1) to miejsce, w którym piszemy program. Otwierając przykładowy program lub poprzednio zapisany, pojawi się on w tym oknie. Możesz otworzyć i korzystać z kilku edytorów na raz. 2. Pasek narzędzi(2) nadaje komendy w edytorze. O różnych zadaniach nauczymy się później. 3. Powierchnia pod edytorem (3) to obszar na wszystkie okna edycji. Nasz pierwszy Program Już znasz podstawy, więc zacznijmy programować. Wpiszmy poniższą linijkę do edytora. TextWindow.WriteLine(„Hello World”) Jeżeli wszystko zostało wpisane poprawnie, to ujżymy coś takiego: Pierwszy Program Teraz, kiedy już napisaliśmy nasz pierwszy program, włączmy go. Możemy to zrobić klikajać na przycisk RUN w pasku narzędzi lub naciskając F5. -
Certification of a Tool Chain for Deductive Program Verification Paolo Herms
Certification of a Tool Chain for Deductive Program Verification Paolo Herms To cite this version: Paolo Herms. Certification of a Tool Chain for Deductive Program Verification. Other [cs.OH]. Université Paris Sud - Paris XI, 2013. English. NNT : 2013PA112006. tel-00789543 HAL Id: tel-00789543 https://tel.archives-ouvertes.fr/tel-00789543 Submitted on 18 Feb 2013 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. UNIVERSITÉ DE PARIS-SUD École doctorale d’Informatique THÈSE présentée pour obtenir le Grade de Docteur en Sciences de l’Université Paris-Sud Discipline : Informatique PAR Paolo HERMS −! − SUJET : Certification of a Tool Chain for Deductive Program Verification soutenue le 14 janvier 2013 devant la commission d’examen MM. Roberto Di Cosmo Président du Jury Xavier Leroy Rapporteur Gilles Barthe Rapporteur Emmanuel Ledinot Examinateur Burkhart Wolff Examinateur Claude Marché Directeur de Thèse Benjamin Monate Co-directeur de Thèse Jean-François Monin Invité Résumé Cette thèse s’inscrit dans le domaine de la vérification du logiciel. Le but de la vérification du logiciel est d’assurer qu’une implémentation, un programme, répond aux exigences, satis- fait sa spécification. Cela est particulièrement important pour le logiciel critique, tel que des systèmes de contrôle d’avions, trains ou centrales électriques, où un mauvais fonctionnement pendant l’opération aurait des conséquences catastrophiques. -
Microsoft Small Basic
Microsoft Small Basic An introduction to Programming Chapter 1 An Introduction Small Basic and Programming Computer Programming is defined as the process of creating computer software using programming languages. Just like we speak and understand English or Spanish or French, computers can understand programs written in certain languages. These are called programming languages. In the beginning there were just a few programming languages and they were really easy to learn and comprehend. But as computers and software became more and more sophisticated, programming languages evolved fast, gathering more complex concepts along the way. As a result most modern programming languages and their concepts are pretty challenging to grasp by a beginner. This fact has started discouraging people from learning or attempting computer programming. Small Basic is a programming language that is designed to make programming extremely easy, approachable and fun for beginners. Small Basic’s intention is to bring down the barrier and serve as a stepping stone to the amazing world of computer programming. The Small Basic Environment Let us start with a quick introduction to the Small Basic Environment. When you first launch SmallBasic, you will see a window that looks like the following figure. Figure 1 - The Small Basic Environment This is the Small Basic Environment, where we’ll write and run our Small Basic programs. This environment has several distinct elements which are identified by numbers. The Editor, identified by [1] is where we will write our Small Basic programs. When you open a sample program or a previously saved program, it will show up on this editor. -
Implementing a Transformation from BPMN to CSP+T with ATL: Lessons Learnt
Implementing a Transformation from BPMN to CSP+T with ATL: Lessons Learnt Aleksander González1, Luis E. Mendoza1, Manuel I. Capel2 and María A. Pérez1 1 Processes and Systems Department, Simón Bolivar University PO Box 89000, Caracas, 1080-A, Venezuela 2 Software Engineering Department, University of Granada Aynadamar Campus, 18071, Granada, Spain Abstract. Among the challenges to face in order to promote the use of tech- niques of formal verification in organizational environments, there is the possi- bility of offering the integration of features provided by a Model Transforma- tion Language (MTL) as part of a tool very used by business analysts, and from which formal specifications of a model can be generated. This article presents the use of MTL ATLAS Transformation Language (ATL) as a transformation artefact within the domains of Business Process Modelling Notation (BPMN) and Communicating Sequential Processes + Time (CSP+T). It discusses the main difficulties encountered and the lessons learnt when building BTRANSFORMER; a tool developed for the Eclipse platform, which allows us to generate a formal specification in the CSP+T notation from a business process model designed with BPMN. This learning is valid for those who are interested in formalizing a Business Process Modelling Language (BPML) by means of a process calculus or another formal notation. 1 Introduction Business Processes (BP) must be properly and formally specified in order to be able to verify properties, such as scope, structure, performance, capacity, structural consis- tency and concurrency, i.e., those properties of BP which can provide support to the critical success factors of any organization. Formal specification languages and proc- ess algebras, which allow for the exhaustive verification of BP behaviour [17], are used to carry out the formalization of models obtained from Business Process Model- ling (BPM).