FLT/Mathlib/LinearAlgebra/Pi.lean
Explanation legend Lean4 Domain Explanation Language (L4DEL)
L4DEL explanations are a separate layer. They do not change the Lean source. Intuition is explanatory prose; numbered items are a reading path; sources link the wording back to evidence.
- L4DEL
- Lean4 Domain Explanation Language
Credit: The upstream authors and contributors retain credit for the project and mathematics. lean4-explainer only renders their pinned source and adds the separately disclosed explanation layer.
Project sources: Pinned project documentation, Pinned FLT blueprint introduction
7 declarations, 0 contain sorry, 0 declared as axioms
Pi
Material destined for Mathlib.
Imported by 3 files
- class
Pi.FiberwiseSMulA class encoding the product scalar multiplication of∀ b : β, R bon∀ a : α, M athat is determined by the fibers of a supplied functionf : α → βon indices line 23 sourceSource documentation
A class encoding the product scalar multiplication of
∀ b : β, R bon∀ a : α, M athat is determined by the fibers of a supplied functionf : α → βon indices. Specifically, iff a = b, then(r • x) a = r b • x afor anyr : ∀ b, R bandx : ∀ a, M a.standard axioms: Quot.sound what this means
Statement uses:
Semiring,AddCommMonoid,Subtype,Eq,Module3 instances, coercions and auxiliary constants left out.
class Pi.FiberwiseSMul {α β : Type*} (f : α → β) (R : β → Type*) (M : α → Type*) [(b : β) → Semiring (R b)] [(a : α) → AddCommMonoid (M a)] [(b : β) → (σ : {a // f a = b}) → Module (R b) (M σ)] [Module ((b : β) → R b) ((a : α) → M a)] : Prop where … - def
LinearEquiv.piScalarPiCongrFiberwiseLetf : α → βbe a function on index types line 35 sourceSource documentation
Let
f : α → βbe a function on index types. A family ofR b-linear equivalences, indexed byb : β, between the product over the fiber ofbunderfgiven as∀ (σ : { a : α // f a = b }) → γ₁ σ.1) ≃ₗ[R b] γ₂ blifts to an equivalence over the products∀ a, γ₁ a ≃ₗ[∀ b, R b] ∀ b, γ₂ bwith product scalars∀ b, R b, provided that∀ b, R bacts on∀ a, γ₁ afiberwise. This isEquiv.piCongrFiberwiseas aLinearEquivwith product scalars.standard axioms: Classical.choice, Quot.sound, propext what this means
Statement uses:
Semiring,AddCommMonoid,Subtype,Eq,Module, Pi.FiberwiseSMul,LinearEquiv,RingHom.idProof uses:
Equiv,Equiv.piCongrFiberwise,LinearEquiv.toEquiv,LinearEquiv.mk,LinearMap.mk,AddHom.mk,Equiv.toFun,Equiv.invFun24 instances, coercions and auxiliary constants left out.
Tactic trace: 4 steps
Open to load the checked before-and-after goal states.
def LinearEquiv.piScalarPiCongrFiberwise {α : Type*} {β : Type*} {R : β → Type*} {γ₁ : α → Type*} {γ₂ : β → Type*} {f : α → β} [(b : β) → Semiring (R b)] [(a : α) → AddCommMonoid (γ₁ a)] [(b : β) → AddCommMonoid (γ₂ b)] [(b : β) → (a : { a : α // f a = b }) → Module (R b) (γ₁ a)] [(b : β) → Module (R b) (γ₂ b)] [Module (∀ b, R b) (∀ a, γ₁ a)] [Pi.FiberwiseSMul f R γ₁] (e : (b : β) → ((σ : { a : α // f a = b }) → γ₁ σ.1) ≃ₗ[R b] γ₂ b) : ((a : α) → γ₁ a) ≃ₗ[∀ b, R b] ((b : β) → γ₂ b) where …Mentions: Pi.FiberwiseSMul
- def
LinearEquiv.piScalarPiCommDocumented declaration: piScalarPiComm line 48 sourceSource documentation
Given
φ : α → β → Type*andR : α → Type*such thatφ a bis anR amodule for alla b, this is the linear equivalence between∀ a b, φ a band∀ b a, φ a bwith product scalars. This isEquiv.piCommas a product-scalarLinearEquiv.standard axioms: Quot.sound, propext what this means
Statement uses:
Semiring,AddCommMonoid,Module,LinearEquiv,RingHom.idProof uses:
Equiv,Equiv.piComm,LinearEquiv.mk,LinearMap.mk,AddHom.mk,Equiv.toFun,Equiv.invFun21 instances, coercions and auxiliary constants left out.
def LinearEquiv.piScalarPiComm {α β : Type*} (R : α → Type*) (φ : α → β → Type*) [∀ a, Semiring (R a)] [∀ a b, AddCommMonoid (φ a b)] [∀ a b, Module (R a) (φ a b)] : ((a : α) → (b : β) → φ a b) ≃ₗ[∀ a, R a] ((b : β) → (a : α) → φ a b) where … - class
Prod.IsProdSMulA class encoding the product scalar multiplication ofR × SonM × Nof the formatx • y = (x.1 • y.1, x.2 • y.2)line 58 sourceSource documentation
A class encoding the product scalar multiplication of
R × SonM × Nof the formatx • y = (x.1 • y.1, x.2 • y.2). Use this as an assumption instead of constructing theR × Saction onM × N.no axioms what this means
Statement uses:
SMul,Prodclass Prod.IsProdSMul (R S M N : Type*) [SMul R M] [SMul S N] [SMul (R × S) (M × N)] : Prop where …
- theorem
Prod.IsProdSMul.smul_fstline 61 sourceno axioms what this means
Statement uses:
SMul,Prod, Prod.IsProdSMul,Eq,Prod.fst,HSMul.hSMulProof uses:
Eq.mpr,Prod.mk,Prod.snd,id,congrArg,Prod.IsProdSMul.map_smul,Eq.refl2 instances, coercions and auxiliary constants left out.
Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
- theorem
Prod.IsProdSMul.smul_sndline 65 sourceno axioms what this means
Statement uses:
SMul,Prod, Prod.IsProdSMul,Eq,Prod.snd,HSMul.hSMulProof uses:
Eq.mpr,Prod.mk,Prod.fst,id,congrArg,Prod.IsProdSMul.map_smul,Eq.refl2 instances, coercions and auxiliary constants left out.
Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
- class
RestrictedProduct.FiberwiseSMulDocumented declaration: FiberwiseSMul line 74 sourceSource documentation
A class encoding the product scalar multiplication of
Πʳ b, [R b, A b]_[𝓕]onΠʳ a, [M a, B a]_[𝓖]that is determined by the fibers of a supplied functionf : α → βon indices. Specifically, iff a = b, then(r • x) a = r b • x afor anyr : ∀ b, R bandx : ∀ a, M a. This isPi.FiberwiseSMulfor restricted products.no axioms what this means
Statement uses:
Set,Filter,Subtype,Eq,SMul,RestrictedProduct1 instances, coercions and auxiliary constants left out.
class RestrictedProduct.FiberwiseSMul {α β : Type*} (f : α → β) (R : (b : β) → Type*) (A : (b : β) → Set (R b)) (𝓕 : Filter β) (M : (a : α) → Type*) (B : (a : α) → Set (M a)) (𝓖 : Filter α) [(b : β) → (σ : { a // f a = b }) → SMul (R b) (M ↑σ)] [SMul (Πʳ b, [R b, A b]_[𝓕]) (Πʳ a, [M a, B a]_[𝓖])] : Prop where …