Formalization of the Equivalence among Completeness Theorems of Real Number in Coq

The formalization of mathematics based on theorem prover becomes increasingly important in mathematics and computer science, and, particularly, formalizing fundamental mathematical theories becomes especially essential. In this paper, we describe the formalization in Coq of eight very representative...

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Main Authors: Yaoshun Fu, Wensheng Yu
Format: Article
Language:English
Published: MDPI AG 2020-12-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/9/1/38
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author Yaoshun Fu
Wensheng Yu
author_facet Yaoshun Fu
Wensheng Yu
author_sort Yaoshun Fu
collection DOAJ
description The formalization of mathematics based on theorem prover becomes increasingly important in mathematics and computer science, and, particularly, formalizing fundamental mathematical theories becomes especially essential. In this paper, we describe the formalization in Coq of eight very representative completeness theorems of real numbers. These theorems include the Dedekind fundamental theorem, Supremum theorem, Monotone convergence theorem, Nested interval theorem, Finite cover theorem, Accumulation point theorem, Sequential compactness theorem, and Cauchy completeness theorem. We formalize the real number theory strictly following Landau’s Foundations of Analysis where the Dedekind fundamental theorem can be proved. We extend this system and complete the related notions and properties for finiteness and sequence. We prove these theorems in turn from Dedekind fundamental theorem, and finally prove the Dedekind fundamental theorem by the Cauchy completeness theorem. The full details of formal proof are checked by the proof assistant Coq, which embodies the characteristics of reliability and interactivity. This work can lay the foundation for many applications, especially in calculus and topology.
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spelling doaj.art-8e4d74242b8e4d7aa21f6b39c3967e872023-11-21T02:36:20ZengMDPI AGMathematics2227-73902020-12-01913810.3390/math9010038Formalization of the Equivalence among Completeness Theorems of Real Number in CoqYaoshun Fu0Wensheng Yu1Beijing Key Laboratory of Space-Ground Interconnection and Convergence, Beijing University of Posts and Telecommunications, Beijing 100876, ChinaBeijing Key Laboratory of Space-Ground Interconnection and Convergence, Beijing University of Posts and Telecommunications, Beijing 100876, ChinaThe formalization of mathematics based on theorem prover becomes increasingly important in mathematics and computer science, and, particularly, formalizing fundamental mathematical theories becomes especially essential. In this paper, we describe the formalization in Coq of eight very representative completeness theorems of real numbers. These theorems include the Dedekind fundamental theorem, Supremum theorem, Monotone convergence theorem, Nested interval theorem, Finite cover theorem, Accumulation point theorem, Sequential compactness theorem, and Cauchy completeness theorem. We formalize the real number theory strictly following Landau’s Foundations of Analysis where the Dedekind fundamental theorem can be proved. We extend this system and complete the related notions and properties for finiteness and sequence. We prove these theorems in turn from Dedekind fundamental theorem, and finally prove the Dedekind fundamental theorem by the Cauchy completeness theorem. The full details of formal proof are checked by the proof assistant Coq, which embodies the characteristics of reliability and interactivity. This work can lay the foundation for many applications, especially in calculus and topology.https://www.mdpi.com/2227-7390/9/1/38real number theorycompleteness theoremsCoqformalizationanalysis
spellingShingle Yaoshun Fu
Wensheng Yu
Formalization of the Equivalence among Completeness Theorems of Real Number in Coq
Mathematics
real number theory
completeness theorems
Coq
formalization
analysis
title Formalization of the Equivalence among Completeness Theorems of Real Number in Coq
title_full Formalization of the Equivalence among Completeness Theorems of Real Number in Coq
title_fullStr Formalization of the Equivalence among Completeness Theorems of Real Number in Coq
title_full_unstemmed Formalization of the Equivalence among Completeness Theorems of Real Number in Coq
title_short Formalization of the Equivalence among Completeness Theorems of Real Number in Coq
title_sort formalization of the equivalence among completeness theorems of real number in coq
topic real number theory
completeness theorems
Coq
formalization
analysis
url https://www.mdpi.com/2227-7390/9/1/38
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