WikiLean Articles · Brain · Recent changes · Proposals · Flags · Stats · About

Diff — Maximal ideal

Revision #2383 → #3070 · back to history

modifiedMaximal spectrumcfba04652b37
FieldFrom #2383To #3070
note`MaximalSpectrum R` is the type of maximal ideals of a commutative ring `R`.`MaximalSpectrum R` is the structure type of maximal ideals of a commutative (semi)ring `R`.
modifiedMaximal one-sided idealsd04bc61484bc
FieldFrom #2383To #3070
noteMathlib's `Ideal` models left ideals (with two-sided in commutative case); right ideals are not a separate first-class concept, so maximal right ideals are not separately formalized.Mathlib's `Ideal` models left ideals (with two-sided in the commutative case); maximal right ideals are not separately formalized.
modifiedLocal ring via unique maximal right idealc1c41a9daf03
FieldFrom #2383To #3070
note`IsLocalRing` is defined via the `a+b=1 → IsUnit a ∨ IsUnit b` condition; equivalence with a unique maximal ideal is `IsLocalRing.maximal_ideal_unique`, but only for (commutative-style) two-sided ideals.`IsLocalRing.maximal_ideal_unique` characterises local rings as those with a unique maximal ideal, but the right-ideal version is not separately formalised.
modified2x2 matrices: unique two-sided but many one-sided maximale8bcf9562912
FieldFrom #2383To #3070
noteNo specific Mathlib statement about maximal ideals of `Matrix (Fin 2) (Fin 2) K` was found.No specific Mathlib statement about the maximal ideals of `Matrix (Fin 2) (Fin 2) K` was found.
modifiedEquivalent conditions for maximal two-sided ideale803a10ea827
FieldFrom #2383To #3070
note`Ideal.isMaximal_iff` gives one characterization (proper + every strictly larger ideal contains 1); the full list of equivalences from the article is not packaged as one decl.`Ideal.isMaximal_iff` gives one characterisation (proper + every strictly larger ideal contains 1); the full list of equivalences is not packaged as a single decl.
modifiedEquivalent conditions for maximal right ideal03c5fc58c80d
FieldFrom #2383To #3070
noteMathlib lacks a dedicated right-ideal API, so this list of equivalences is not formalized.Mathlib lacks a dedicated right-ideal API, so this list of equivalences is not formalised.
modifiedField has only {0} as maximal ideal7ae486c36fd9
FieldFrom #2383To #3070
note`Ideal.bot_isMaximal` proves `⊥` is maximal in a division (semi)ring, which together with `eq_bot_or_top` for ideals of a field captures the example.`Ideal.bot_isMaximal` proves `⊥` is maximal in a division ring, capturing the example.
modifiedNonzero primes maximal in PID5a222d23e00f
FieldFrom #2383To #3070
note`PrincipalIdealRing.isMaximal_of_irreducible` together with `Ideal.IsPrime.isMaximal` (under `DimensionLEOne`) gives the result; PIDs are zero/one-dimensional so nonzero primes are maximal.`PrincipalIdealRing.isMaximal_of_irreducible` gives that the ideal generated by an irreducible element of a PID is maximal, matching nonzero primes.
modifiedMaximal ideals of Z[x]dd6e28b6be45
FieldFrom #2383To #3070
noteNo explicit Mathlib characterization of the maximal ideals of `ℤ[X]` was found.No explicit Mathlib characterisation of the maximal ideals of `ℤ[X]` was found.
modifiedBoolean ring: every prime is maximalb338269ee5f3
FieldFrom #2383To #3070
noteMathlib's `BooleanRing` file has no theorem identifying prime and maximal ideals.Mathlib's `BooleanRing` file has no theorem identifying prime and maximal ideals in a Boolean ring.
modifiedMaximal ideals of k[x]403c05bd9b5a
FieldFrom #2383To #3070
note`PrincipalIdealRing.isMaximal_of_irreducible` applied to `k[X]` (which is a PID over a field) gives that ideals generated by irreducible polynomials are maximal.`PrincipalIdealRing.isMaximal_of_irreducible` applied to `k[X]` (a PID over a field) yields that ideals generated by irreducible polynomials are maximal.
modifiedWeak Nullstellensatz2aa90673994f
FieldFrom #2383To #3070
note`MvPolynomial.isMaximal_iff_eq_vanishingIdeal_singleton` characterizes maximal ideals of `k[x₁,…,xₙ]` over an algebraically closed field as vanishing ideals of points.`MvPolynomial.isMaximal_iff_eq_vanishingIdeal_singleton` characterises maximal ideals of `k[x₁,…,xₙ]` over an algebraically closed field as vanishing ideals of singletons.
modifiedMaximal ideals of coordinate ringa2f438c882bc
FieldFrom #2383To #3070
noteNo direct Mathlib statement was found describing maximal ideals of the coordinate ring of an affine variety.No direct Mathlib statement describing the maximal ideals of the coordinate ring of an affine variety was found.
modifiedRadical ring has no maximal one-sided idealse375bd7fe9f4
FieldFrom #2383To #3070
noteNo Mathlib decl about radical rings (Jacobson radical = whole ring) and absence of one-sided maximal ideals was found.No Mathlib decl about radical rings (Jacobson radical = whole ring) and the absence of maximal one-sided ideals was found.
modifiedMaximal implies prime in commutative ring91f0199648b5
FieldFrom #2383To #3070
note`Ideal.IsMaximal.isPrime` (with an `instance IsMaximal.isPrime'`) gives that maximal ideals of a commutative (semi)ring are prime.`Ideal.IsMaximal.isPrime` (with `instance IsMaximal.isPrime'`) gives that maximal ideals of a commutative (semi)ring are prime.
modifiedZero-dimensional ring8d63d6fbc5a6
FieldFrom #2383To #3070
note`Ring.KrullDimLE 0 R` expresses that the Krull dimension of `R` is at most zero, i.e., every prime ideal is maximal.`Ring.KrullDimLE 0 R` expresses that the Krull dimension of `R` is at most zero, characterised by `Ring.krullDimLE_zero_iff` as every prime ideal being maximal.
modifiedPreimage under k-algebra homomorphism6e58fb77afc9
FieldFrom #2383To #3070
noteMathlib has the Jacobson-ring machinery (`Polynomial.isMaximal_comap_C_of_isJacobsonRing`, `MvPolynomial.comp_C_integral_of_surjective_of_isJacobsonRing`) from which this preimage statement follows, but no direct lemma `(comap of maximal under finitely generated k-algebra hom is maximal)`.Mathlib has the Jacobson-ring machinery (`Polynomial.isMaximal_comap_C_of_isJacobsonRing`, `MvPolynomial.comp_C_integral_of_surjective_of_isJacobsonRing`) from which this preimage statement follows, but no packaged 'comap of maximal under finitely generated k-algebra hom is maximal' lemma.
modifiedMaximal submodule977ba3888834
FieldFrom #2383To #3070
noteMathlib expresses 'maximal submodule' as `IsCoatom (N : Submodule R M)` using the general order-theoretic `IsCoatom`; there is no dedicated `Submodule.IsMaximal`.Mathlib expresses 'maximal submodule' via the general order-theoretic `IsCoatom (N : Submodule R M)`; there is no dedicated `Submodule.IsMaximal`.
modifiedMaximal right ideals = maximal submodules of R_R0c276dab7e4d
FieldFrom #2383To #3070
note`Ideal.isMaximal_def` (`I.IsMaximal ↔ IsCoatom I`) gives this identification for left ideals (Mathlib's `Ideal R = Submodule R R`); the right-ideal version is not separately formalized.`Ideal.isMaximal_def` (`I.IsMaximal ↔ IsCoatom I`) gives this identification for left ideals (`Ideal R = Submodule R R`); the right-ideal version is not separately formalised.
modifiedExistence of maximal submodulesc79ba34835c6
FieldFrom #2383To #3070
mathlib.declModule.Finite.instIsCoatomicSubmoduleSubmodule.instIsCoatomicOfFinite
note`Module.Finite.instIsCoatomicSubmodule` gives `IsCoatomic (Submodule R M)` for finitely generated `M`; the projective-module case is not formalized.An unnamed instance in `Mathlib.RingTheory.Finiteness.Basic` supplies `IsCoatomic (Submodule R M)` for `[Module.Finite R M]`; the projective-module case is not formalised.
modifiedJacobson radical via maximal ideals0c9ba1b09ab1
FieldFrom #2383To #3070
note`Ideal.jacobson` formalizes the Jacobson radical as the intersection of all maximal ideals above a given ideal; `Ring.jacobson` (in `Mathlib.RingTheory.Jacobson.Radical`) gives the radical of the ring itself.`Ideal.jacobson` formalises the Jacobson radical as the infimum of all maximal ideals containing the given ideal; `Ring.jacobson` in `Mathlib.RingTheory.Jacobson.Radical` specialises this to the whole ring.
modifiedEvery nonzero finitely generated module has a maximal submodule398af5db4653
FieldFrom #2383To #3070
mathlib.declModule.Finite.instIsCoatomicSubmoduleSubmodule.instIsCoatomicOfFinite
noteThe `IsCoatomic (Submodule R M)` instance for finitely generated `M` combined with `IsCoatomic.eq_top_or_exists_le_coatom` yields the existence of a maximal submodule (`IsCoatom`) above any proper submodule.The `IsCoatomic (Submodule R M)` instance for `[Module.Finite R M]` combined with `IsCoatomic.eq_top_or_exists_le_coatom` yields the existence of a maximal submodule above any proper submodule.
addedPrime spectrum584ad0ddae6d
addedSimple module (quotient by maximal one-sided ideal)785d4474ba95
addedSimple ringf2fa950a070d