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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">mais</journal-id><journal-title-group><journal-title xml:lang="ru">Моделирование и анализ информационных систем</journal-title><trans-title-group xml:lang="en"><trans-title>Modeling and Analysis of Information Systems</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">1818-1015</issn><issn pub-type="epub">2313-5417</issn><publisher><publisher-name>Yaroslavl State University</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.18255/1818-1015-2018-6-637-666</article-id><article-id custom-type="elpub" pub-id-type="custom">mais-764</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>Оригинальные статьи</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>Articles</subject></subj-group></article-categories><title-group><article-title>Платформенно-независимая спецификация и верификация стандартной математической функции квадратного корня</article-title><trans-title-group xml:lang="en"><trans-title>Platform-independent Specification and Verification of the Standard Mathematical Square Root Function</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-7515-9647</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Шилов</surname><given-names>Николай Вячеславович</given-names></name><name name-style="western" xml:lang="en"><surname>Shilov</surname><given-names>Nikolay V.</given-names></name></name-alternatives><bio xml:lang="ru"><p>канд. физ.-мат. наук, доцент</p><p>ул. Университетская, 1, г. Иннополис, Республика Татарстан, 420500</p></bio><bio xml:lang="en"><p>PhD</p><p>1 Universitetskaya str., Innopolis, Tatarstan Republic, 420500</p></bio><email xlink:type="simple">shiloviis@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-9387-6735</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Кондратьев</surname><given-names>Дмитрий Александрович</given-names></name><name name-style="western" xml:lang="en"><surname>Kondratyev</surname><given-names>Dmitry A.</given-names></name></name-alternatives><bio xml:lang="ru"><p>аспирант</p><p>пр. акад. Лаврентьева, 6, г. Новосибирск, 630090</p></bio><bio xml:lang="en"><p>postgraduate student</p><p>6, Acad. Lavrentjev pr., Novosibirsk 630090</p></bio><email xlink:type="simple">apple-66@mail.ru</email><xref ref-type="aff" rid="aff-2"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-9574-128X</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Ануреев</surname><given-names>Игорь Сергеевич</given-names></name><name name-style="western" xml:lang="en"><surname>Anureev</surname><given-names>Igor S.</given-names></name></name-alternatives><bio xml:lang="ru"><p>канд. физ.-мат. наук, ст. науч. сотр.</p><p>пр. акад. Лаврентьева, 6, г. Новосибирск, 630090</p></bio><bio xml:lang="en"><p>PhD, senior researcher</p><p>6, Acad. Lavrentjev pr., Novosibirsk 630090</p></bio><email xlink:type="simple">anureev@iis.nsk.su</email><xref ref-type="aff" rid="aff-2"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-5882-0365</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Бодин</surname><given-names>Евгений Викторович</given-names></name><name name-style="western" xml:lang="en"><surname>Bodin</surname><given-names>Eugene V.</given-names></name></name-alternatives><bio xml:lang="ru"><p>науч. сотр.</p><p>пр. акад. Лаврентьева, 6, г. Новосибирск, 630090</p></bio><bio xml:lang="en"><p>researcher</p><p>6, Acad. Lavrentjev pr., Novosibirsk 630090</p></bio><email xlink:type="simple">bodin@iis.nsk.su</email><xref ref-type="aff" rid="aff-2"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-5963-2390</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Промский</surname><given-names>Алексей Владимирович</given-names></name><name name-style="western" xml:lang="en"><surname>Promsky</surname><given-names>Alexei V.</given-names></name></name-alternatives><bio xml:lang="ru"><p>канд. физ.-мат. наук, ученый секретарь</p><p>пр. акад. Лаврентьева, 6, г. Новосибирск, 630090</p></bio><bio xml:lang="en"><p>PhD, scientific secretary</p><p>6, Acad. Lavrentjev pr., Novosibirsk 630090</p></bio><email xlink:type="simple">promsky@iis.nsk.su</email><xref ref-type="aff" rid="aff-2"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>Автономная некоммерческая организация высшего образования “Университет Иннополис”</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Autonomous noncommercial organization of higher education "Innopolis University"</institution><country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-2"><aff xml:lang="ru"><institution>Институт систем информатики имени А.П. Ершова СО РАН</institution><country>Россия</country></aff><aff xml:lang="en"><institution>A.P. Ershov Institute of Informatics Systems</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2018</year></pub-date><pub-date pub-type="epub"><day>19</day><month>12</month><year>2018</year></pub-date><volume>25</volume><issue>6</issue><fpage>637</fpage><lpage>666</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Шилов Н.В., Кондратьев Д.А., Ануреев И.С., Бодин Е.В., Промский А.В., 2018</copyright-statement><copyright-year>2018</copyright-year><copyright-holder xml:lang="ru">Шилов Н.В., Кондратьев Д.А., Ануреев И.С., Бодин Е.В., Промский А.В.</copyright-holder><copyright-holder xml:lang="en">Shilov N.V., Kondratyev D.A., Anureev I.S., Bodin E.V., Promsky A.V.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://www.mais-journal.ru/jour/article/view/764">https://www.mais-journal.ru/jour/article/view/764</self-uri><abstract><p>Цель проекта “Платформенно-независимый подход к формальной спецификации и верификации стандартных математических функций” --- инкрементальный комбинированный подход к спецификации и верификации стандартных математических функций, таких как sqrt, cos, sin и так далее. Платформенно-независимый подход предполагает простую аксиоматизацию машинной арифметики в терминах вещественной арифметики (то есть арифметики поля \(\mathbb{R}\) вещественных чисел), не фиксируя ни основание системы счисления, ни формат машинного слова. Инкрементальность означает, что спецификация и верификация начинается с рассмотрения наиболее “простого” случая – элементарной спецификации и верификации простого алгоритма, работающего с вещественными числами, а заканчивается модификацией элементарной спецификации и алгоритма для машинной арифметики и верификацией алгоритма, работающего в машинной арифметике. А комбинированность подхода означает, что мы начинаем с рассмотрения “базового случая” --- “ручной” верификации (с ручкой и бумагой) для алгоритма, работающего в вещественной арифметике, затем выполняем ручную верификацию алгоритма, работающего в машинной арифметике, используя верификацию для базового случая в качестве “конспекта” (proof-outlines), а заканчиваем --- верификацией с использованием автоматизированной системы построения/поиска доказательства для того, чтобы исключить апелляцию к “очевидности” в ручной верификации. В статье платформенно-независимый инкрементальный комбинированный подход применяется для спецификации и верификации стандартной математической функции квадратного корня. В настоящий момент автоматизированная верификация разработанных алгоритмов выполнена только частично: с использованием системы ACL2 доказана реализуемость (существование) чисел с фиксированной запятой и таблицы начальных приближений квадратного корня.</p></abstract><trans-abstract xml:lang="en"><p>The project “Platform-independent approach to formal specification and verification of standard mathematical functions” is aimed onto the development of incremental combined approach to specification and verification of standard Mathematical functions like sqrt, cos, sin, etc. Platform-independence means that we attempt to design a relatively simple axiomatization of the computer arithmetics in terms of real arithmetics (i.e. the field \(\mathbb{R}\) of real numbers) but do not specify neither base of the computer arithmetics, nor a format of numbers representation. Incrementality means that we start with the most straightforward specification of the simplest case to verify the algorithm in real numbers and finish with a realistic specification and a verification of the algorithm in computer arithmetics. We call our approach combined because we start with manual (pen-and-paper) verification of the algorithm in real numbers, then use this verification as proof-outlines for a manual verification of the algorithm in computer arithmetics, and finish with a computer-aided validation of the manual proofs with a proof-assistant system (to avoid appeals to “obviousness” that are common in human-carried proofs). In the paper, we apply our platform-independent incremental combined approach to specification and verification of the standard Mathematical square root function. Currently a computer-aided validation was carried for correctness (consistency) of our fix-point arithmetics and for the existence of a look-up table with the initial approximations of the square roots for fix-point numbers.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>числа с фиксированной запятой</kwd><kwd>числа с плавающей запятой</kwd><kwd>машинная арифметика</kwd><kwd>формальная верификация</kwd><kwd>частичная и тотальная корректность</kwd><kwd>тройки Хоара</kwd><kwd>метод Флойда</kwd><kwd>точная функция</kwd><kwd>квадратный корень</kwd><kwd>метод Ньютона</kwd><kwd>справочная таблица</kwd></kwd-group><kwd-group xml:lang="en"><kwd>fix-point numbers</kwd><kwd>floating-point numbers</kwd><kwd>computer arithmetic</kwd><kwd>formal verification</kwd><kwd>partial and total correctness</kwd><kwd>Hoare triples</kwd><kwd>Floyd verification method of inductive assertions</kwd><kwd>exact function</kwd><kwd>square root function</kwd><kwd>Newton–Raphson method</kwd><kwd>look-up table</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Кулямин В.В., “Стандартизация и тестирование реализаций математических функций, работающих с числами с плавающей точкой”, Программирование, 33:3 (2007), 1–29;</mixed-citation><mixed-citation xml:lang="en">Kuliamin V.V., “Standardization and testing of implementations of mathematical functions in floating point numbers”, Programming and Computer Software, 33:3 (2007), 154–173.</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Никитин В.Ф., Вариант вычисления квадратного корня (алгоритм Ньютона), http://algolist.manual.ru/maths/count_fast/sqrt.php;</mixed-citation><mixed-citation xml:lang="en">Nikitin V.F., Variant vychisleniya kvadratnogo kornya (algoritm Nyutona), http://algolist.manual.ru/ maths/count_fast/sqrt.php, (in Russian).</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Шелехов В.И., “Верификация и синтез эффективных программ стандартных функций floor, isqrt и ilog2 в технологии предикатного программирования”, Проблемы управления и моделирования в сложных системах, Труды 12-й межд. конф. 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