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Project-declaredLean 4.31.0 · mathlib@fabf563a

Prop2d8₂I

HarderNarasimhan.impl.prop2d8₂I

Plain-language statement

Proposition 2.8 (b): under comparability or attainment, one of the two μA values is dominated by μA (u, x ⊔ y). This is a “one-sided dominance” conclusion that matches the alternative in the paper statement.

Exact Lean statement

lemma prop2d8₂I
  (I : {p : ℒ × ℒ // p.1 < p.2})
  (μ : {p :ℒ × ℒ // p.1 < p.2} → S) (hμcvx : ConvexI I μ)
  (x : ℒ) (hxI : InIntvl I x)
  (y : ℒ) (hyI : InIntvl I y)
  (u : ℒ) (huI : InIntvl I u)
  (h : u < x ∧ u < y)
  (hcpb : IsComparable (μA μ ⟨(u, x), h.1⟩)
  (μA μ ⟨(u, y), h.2⟩) ∨ IsAttained μ ⟨(u, x ⊔ y), lt_sup_of_lt_left h.1⟩) :
  μA μ ⟨(u, x), h.1⟩ ≤ μA μ ⟨(u, x ⊔ y), lt_sup_of_lt_left h.1⟩ ∨
  μA μ ⟨(u, y), h.2⟩ ≤ μA μ ⟨(u, x ⊔ y), lt_sup_of_lt_left h.1⟩

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
lemma prop2d8₂I  (I : {p : ℒ × ℒ // p.1 < p.2})  (μ : {p :ℒ × ℒ // p.1 < p.2}  S) (hμcvx : ConvexI I μ)  (x : ℒ) (hxI : InIntvl I x)  (y : ℒ) (hyI : InIntvl I y)  (u : ℒ) (huI : InIntvl I u)  (h : u < x  u < y)  (hcpb : IsComparable (μA μ (u, x), h.1)  (μA μ (u, y), h.2)  IsAttained μ (u, x ⊔ y), lt_sup_of_lt_left h.1) :  μA μ (u, x), h.1  μA μ (u, x ⊔ y), lt_sup_of_lt_left h.1   μA μ (u, y), h.2  μA μ (u, x ⊔ y), lt_sup_of_lt_left h.1 := by  rcases hcpb with h₁ | h₂  · rcases h₁ with h₃ | h₄    · exact Or.inl <| (inf_eq_left.2 h₃).symm ▸ (prop2d8₁I I μ hμcvx x hxI y hyI u huI h)    · have h' : μA μ (u, x), h.1 ⊓ μA μ (u, y), h.2  μA μ (u, x ⊔ y), lt_sup_of_lt_left h.1        := prop2d8₁I I μ hμcvx x hxI y hyI u huI h      rw [inf_comm] at h'      exact Or.inr <| (inf_eq_left.2 h₄).symm ▸ h'  · rcases h₂ with a, ha, ha',ha''⟩⟩    exact ha'' ▸ (prop2d8₀I I μ hμcvx x hxI y hyI u h a le_trans huI.1 ha.1, le_trans ha.2 <|      sup_le hxI.2 hyI.2 ha.1,lt_of_le_of_ne ha.2 ha')
Project
Harder-Narasimhan
License
Apache-2.0
Commit
20220e90b72c
Source
HarderNarasimhan/Convexity/Impl.lean:492-512

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Project-declaredLean 4.31.0

Associated Primes ker mk Linear Map eq

HarderNarasimhan.CommutativeAlgebra.associatedPrimes_ker_mkLinearMap_eq

Project documentation

Associated primes of the kernel of the localization map. This identifies the associated primes of ker (LocalizedModule.mkLinearMap S M) : Submodule R M with the associated primes of M that do meet the multiplicative set S. Equivalently, these are the associated primes of M after removing those disjoint from S. This lemma is used as the “kernel...

algebraic geometryvector bundlescategory theory

Source project: Harder-Narasimhan

Person-level attribution pending.

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Project-declaredLean 4.31.0

Associated Primes ker mk Linear Map subset

HarderNarasimhan.CommutativeAlgebra.associatedPrimes_ker_mkLinearMap_subset

Plain-language statement

One-sided inclusion for associated primes of the kernel of the localization map. If p ∈ associatedPrimes R (ker (mkLinearMap S M)), then p is an associated prime of M and p is not disjoint from the multiplicative set S. This is one direction of associatedPrimes_ker_mkLinearMap_eq.

algebraic geometryvector bundlescategory theory

Source project: Harder-Narasimhan

Person-level attribution pending.

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Project-declaredLean 4.31.0

Associated Primes localized Module subset disjoint

HarderNarasimhan.CommutativeAlgebra.associatedPrimes_localizedModule_subset_disjoint

Plain-language statement

Associated primes of a localized module are disjoint from the multiplicative set. More precisely, if p ∈ associatedPrimes R (LocalizedModule S M), then p.carrier ∩ S = ∅. This is a standard fact in commutative algebra: an element of S becomes a unit after localization, so no associated prime of the localized module can contain an element of S.

algebraic geometryvector bundlescategory theory

Source project: Harder-Narasimhan

Person-level attribution pending.

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