100 theorems in Lean

6 hours ago 3

Freek Wiedijk maintains a list tracking progress of theorem provers in formalizing 100 classic theorems in mathematics as a way of comparing prominent theorem provers. Currently 81 of them are formalized in Lean, and 0 additional theorem(s) have just their statement formalized in Lean. We also have a page with the theorems from the list not yet in Lean.

To make updates to this list, please make a pull request to mathlib after editing the yaml source file. This can be done entirely on GitHub, see "Editing files in another user's repository".

1. The Irrationality of the Square Root of 2 #

Author: mathlib

docs, source

2. Fundamental Theorem of Algebra #

Author: Chris Hughes

docs, source

3. The Denumerability of the Rational Numbers #

Author: Chris Hughes

docs, source

4. Pythagorean Theorem #

Author: Joseph Myers

docs, source

6. Gödel’s Incompleteness Theorem #

Author: Shogo Saito

First incompleteness theorem

Second incompleteness theorem

website

7. Law of Quadratic Reciprocity #

Authors: Chris Hughes (first) and Michael Stoll (second)

docs, source

docs, source

9. The Area of a Circle #

Authors: James Arthur and Benjamin Davidson and Andrew Souther

docs, source

10. Euler’s Generalization of Fermat’s Little Theorem #

Author: Chris Hughes

docs, source

11. The Infinitude of Primes #

Author: Jeremy Avigad

docs, source

14. Euler’s Summation of 1 + (1/2)^2 + (1/3)^2 + …. #

Authors: Marc Masdeu and David Loeffler

docs, source

15. Fundamental Theorem of Integral Calculus #

Authors: Yury G. Kudryashov (first) and Benjamin Davidson (second)

docs, source

docs, source

16. Insolvability of General Higher Degree Equations (Abel-Ruffini Theorem) #

Author: Thomas Browning

docs, source

17. De Moivre’s Formula #

Author: Abhimanyu Pallavi Sudhir

docs, source

18. Liouville’s Theorem and the Construction of Transcendental Numbers #

Author: Jujian Zhang

docs, source

19. Four Squares Theorem #

Author: Chris Hughes

docs, source

20. All Primes (1 mod 4) Equal the Sum of Two Squares #

Author: Chris Hughes

docs, source

22. The Non-Denumerability of the Continuum #

Author: Floris van Doorn

docs, source

23. Formula for Pythagorean Triples #

Author: Paul van Wamelen

docs, source

24. The Independence of the Continuum Hypothesis #

Authors: Jesse Michael Han and Floris van Doorn

result

website

see the README file in the linked repository.

25. Schroeder-Bernstein Theorem #

Author: Mario Carneiro

docs, source

26. Leibniz’s Series for Pi #

Author: Benjamin Davidson

docs, source

27. Sum of the Angles of a Triangle #

Author: Joseph Myers

docs, source

30. The Ballot Problem #

Authors: Bhavik Mehta and Kexing Ying

docs, source

31. Ramsey’s Theorem #

Author: Bhavik Mehta

result

34. Divergence of the Harmonic Series #

Authors: Anatole Dedecker and Yury Kudryashov

docs, source

35. Taylor’s Theorem #

Author: Moritz Doll

docs, source

docs, source

36. Brouwer Fixed Point Theorem #

Author: Brendan Seamas Murphy

result

37. The Solution of a Cubic #

Author: Jeoff Lee

docs, source

38. Arithmetic Mean/Geometric Mean #

Author: Yury G. Kudryashov

docs, source

39. Solutions to Pell’s Equation #

Author: Mario Carneiro (first), Michael Stoll (second)

docs, source

docs, source

In pell.eq_pell, d is defined to be a*a - 1 for an arbitrary a > 1.

40. Minkowski’s Fundamental Theorem #

Authors: Alex J. Best and Yaël Dillies

docs, source

42. Sum of the Reciprocals of the Triangular Numbers #

Authors: Jalex Stark and Yury Kudryashov

docs, source

44. The Binomial Theorem #

Author: Chris Hughes

docs, source

45. The Partition Theorem #

Authors: Bhavik Mehta and Aaron Anderson

docs, source

46. The Solution of the General Quartic Equation #

Author: Thomas Zhu

docs, source

48. Dirichlet’s Theorem #

Author: David Loeffler, Michael Stoll

docs, source

49. The Cayley-Hamilton Theorem #

Author: Kim Morrison

docs, source

51. Wilson’s Lemma #

Author: Chris Hughes

docs, source

52. The Number of Subsets of a Set #

Author: mathlib

docs, source

54. Königsberg Bridges Problem #

Author: Kyle Miller

docs, source

55. Product of Segments of Chords #

Author: Manuel Candales

docs, source

57. Heron’s Formula #

Author: Matt Kempster

docs, source

58. Formula for the Number of Combinations #

Author: mathlib

docs, source

docs, source

59. The Laws of Large Numbers #

Author: Sébastien Gouëzel

docs, source

60. Bezout’s Theorem #

Author: mathlib

docs, source

62. Fair Games Theorem #

Author: Kexing Ying

docs, source

63. Cantor’s Theorem #

Authors: Johannes Hölzl and Mario Carneiro

docs, source

64. L’Hopital’s Rule #

Author: Anatole Dedecker

docs, source

65. Isosceles Triangle Theorem #

Author: Joseph Myers

docs, source

66. Sum of a Geometric Series #

Authors: Sander R. Dahmen (finite) and Johannes Hölzl (infinite)

docs, source

docs, source

67. e is Transcendental #

Author: Jujian Zhang

result

website

68. Sum of an arithmetic series #

Author: Johannes Hölzl

docs, source

69. Greatest Common Divisor Algorithm #

Author: mathlib

docs, source

docs, source

docs, source

70. The Perfect Number Theorem #

Author: Aaron Anderson

docs, source

71. Order of a Subgroup #

Author: mathlib

docs, source

72. Sylow’s Theorem #

Author: Chris Hughes

docs, source

docs, source

docs, source

docs, source

73. Ascending or Descending Sequences (Erdős–Szekeres Theorem) #

Author: Bhavik Mehta

docs, source

74. The Principle of Mathematical Induction #

Author: Leonardo de Moura

docs, source

Automatically generated when defining the natural numbers

75. The Mean Value Theorem #

Author: Yury G. Kudryashov

docs, source

76. Fourier Series #

Author: Heather Macbeth

docs, source

docs, source

77. Sum of kth powers #

Authors: Moritz Firsching and Fabian Kruse and Ashvni Narayanan

docs, source

docs, source

78. The Cauchy-Schwarz Inequality #

Author: Zhouhang Zhou

docs, source

docs, source

79. The Intermediate Value Theorem #

Authors: Rob Lewis and Chris Hughes

docs, source

80. The Fundamental Theorem of Arithmetic #

Author: Chris Hughes

docs, source

docs, source

docs, source

docs, source

docs, source

it also has a generalized version, by showing that every Euclidean domain is a unique factorization domain, and showing that the integers form a Euclidean domain.

81. Divergence of the Prime Reciprocal Series #

Author: Manuel Candales (archive), Michael Stoll (mathlib)

docs, source

docs, source

82. Dissection of Cubes (J.E. Littlewood’s ‘elegant’ proof) #

Author: Floris van Doorn

docs, source

83. The Friendship Theorem #

Authors: Aaron Anderson and Jalex Stark and Kyle Miller

docs, source

85. Divisibility by 3 Rule #

Author: Kim Morrison

docs, source

86. Lebesgue Measure and Integration #

Author: Johannes Hölzl

docs, source

88. Derangements Formula #

Author: Henry Swanson

docs, source

docs, source

89. The Factor and Remainder Theorems #

Author: Chris Hughes

docs, source

docs, source

90. Stirling’s Formula #

Authors: Moritz Firsching and Fabian Kruse and Nikolas Kuhn and Heather Macbeth

docs, source

91. The Triangle Inequality #

Author: Zhouhang Zhou

docs, source

93. The Birthday Problem #

Author: Eric Rodriguez

docs, source

docs, source

94. The Law of Cosines #

Author: Joseph Myers

docs, source

95. Ptolemy’s Theorem #

Author: Manuel Candales

docs, source

96. Principle of Inclusion/Exclusion #

Author: Neil Strickland (outside mathlib), Yaël Dillies (in mathlib)

docs, source

docs, source

docs, source

docs, source

github

97. Cramer’s Rule #

Author: Anne Baanen

docs, source

98. Bertrand’s Postulate #

Authors: Bolton Bailey and Patrick Stevens

docs, source

99. Buffon Needle Problem #

Author: Enrico Z. Borba

docs, source

docs, source

100. Descartes Rule of Signs #

Author: Alex Meiburg

github

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