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Diff — Pure mathematics

Revision #3449 → #4001 · back to history

modifiedIrrationality proof of the Pythagoreans3abe5d94b821
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noteThe classical Pythagorean result that √2 is irrational is stated directly as `irrational_sqrt_two`.Verified: the classical Pythagorean result that √2 is irrational is stated directly as `irrational_sqrt_two` in Mathlib.NumberTheory.Real.Irrational.
modifiedCantor's theorem on uncountable sets1f0c2c779250
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noteCantor's diagonal result that no function `α → Set α` is surjective—the foundational theorem of his theory of infinite sets—is `Function.cantor_surjective`; the cardinal form is `Cardinal.cantor`.Verified: Cantor's diagonal result that no function `α → Set α` is surjective is `Function.cantor_surjective` in Mathlib.Logic.Function.Basic.
modifiedRussell's paradoxbab8a0176b3b
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noteThe naive-set-theoretic Russell paradox is implicit in Lean's type-theoretic foundation (the set of all sets that do not contain themselves cannot be formed) but is not stated as a named declaration in Mathlib.The naive-set-theoretic Russell paradox is implicit in Lean's type-theoretic foundation but is not stated as a named declaration in Mathlib.
modifiedGödel's incompleteness theoremscab258531e8f
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noteGödel's first and second incompleteness theorems are not formalized in Mathlib; a separate project (FormalizingMathematics / Paulson's Isabelle work, and a Lean effort by Shing Tak Lam) exists outside Mathlib.Gödel's first and second incompleteness theorems are not formalized in Mathlib.
modifiedCategory theory4350fff018a4
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noteThe foundational notion of a category is formalized as `CategoryTheory.Category`, with an extensive library on functors, natural transformations, limits, and adjunctions built on top.Verified: `CategoryTheory.Category` is defined at Mathlib/CategoryTheory/Category/Basic.lean:235, with an extensive library built on top.
modifiedCommutative ring (vs non-commutative ring)e6cbb9828f8e
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noteMagid's ring-theory analogy refers to the standard distinction between `Ring` (not-necessarily-commutative) and `CommRing` (commutative); both are core algebraic typeclasses in Mathlib.Verified: `CommRing` is defined in Mathlib.Algebra.Ring.Defs alongside `Ring`.
modifiedConic sections1d32509e9b5e
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noteMathlib has the individual conics (circle, ellipse, parabola, hyperbola) treated piecemeal via quadratic forms and affine geometry, but no unified Apollonian theory of conic sections as plane sections of a cone.Mathlib has the individual conics (circle, ellipse, parabola, hyperbola) treated piecemeal, but no unified Apollonian theory of conic sections as plane sections of a cone.
modifiedLanglands programc2dce9b8e83f
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noteNeither the classical nor the geometric Langlands correspondence is formalized in Mathlib; pieces of the prerequisite automorphic-forms and Galois-representations infrastructure exist but no Langlands-style functoriality statement.Neither the classical nor the geometric Langlands correspondence is formalized in Mathlib.
modifiedTopology (topological space)a7418f7a6f03
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notePoint-set topology, the 20th-century formalization referenced here, is captured by the `TopologicalSpace` typeclass with a vast Mathlib development on continuity, compactness, and connectedness.Verified: the `TopologicalSpace` typeclass is defined in Mathlib.Topology.Defs.Basic.
modifiedGroup theory04b98ad7e7e8
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noteThe `Group` typeclass is a core algebraic structure in Mathlib, with a large body of finite/abelian/Lie group theory built on it.Verified: `class Group` is at Mathlib/Algebra/Group/Defs.lean:33.
modifiedMatrix theoryd54d3fa60d3b
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noteMatrices over a semiring are formalized as `Matrix m n α` (in `Mathlib.LinearAlgebra.Matrix.Defs`), with a rich Mathlib API covering determinants, invertibility, eigenvalues, and spectral theory.Verified: `def Matrix` is at Mathlib/LinearAlgebra/Matrix/Defs.lean:57.
modifiedFunctional analysis2b6294fd5671
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noteFunctional analysis is a mature Mathlib area (normed and Banach spaces, Hilbert spaces, operator theory, Hahn–Banach); `NormedSpace` (in `Mathlib.Analysis.Normed.Module.Basic`) is a representative foundational typeclass.Functional analysis is a mature Mathlib area; `NormedSpace` in Mathlib.Analysis.Normed.Module.Basic is a representative foundational typeclass.
modifiedDynamical systemsdfa950dc8c02
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noteMathlib's `Dynamics` folder covers fixed points, periodic points, ergodic theory, and topological dynamics; `Function.IsFixedPt` (defined in `Mathlib.Logic.Function.Defs`) is a representative foundational declaration.Verified: `Function.IsFixedPt` is at Mathlib/Logic/Function/Defs.lean:214, with Mathlib's `Dynamics` folder covering periodic points, ergodic theory, and topological dynamics.
modifiedNumber theorycb8cc892ad20
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noteNumber theory is a large Mathlib area; `Nat.Prime` (in `Mathlib.Data.Nat.Prime.Defs`) is a representative core declaration and the folder `Mathlib.NumberTheory` develops arithmetic, L-functions, and modular forms.Number theory is a large Mathlib area; `Nat.Prime` in Mathlib.Data.Nat.Prime.Defs is a representative core declaration, and Mathlib.NumberTheory develops arithmetic, L-functions, and modular forms.
modifiedAlgebraic geometrya308c2a67c88
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noteAlgebraic geometry in Mathlib is developed around the `AlgebraicGeometry.Scheme` structure and the wider `Mathlib.AlgebraicGeometry` folder covering sheaves, morphisms, and projective schemes.Verified: algebraic geometry in Mathlib is developed around the `AlgebraicGeometry.Scheme` structure in Mathlib.AlgebraicGeometry.Scheme.
addedStatistics4545e7405890
addedPolynomial and rational functions64b060645ad7
addedSet theory (foundation for curriculum)d272412dfc06
addedLean proof assistantd163a5108833