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FLT.Mathlib.Logic.Equiv.Basic

def Equiv.piCongrSigmaFiber {α : Type u_1} {β : Type u_2} {f : αβ} {γ₁ : αSort u_3} {γ₂ : αSort u_4} (e : (a : α) → γ₁ a γ₂ a) :
((σ : (y : β) × { x : α // f x = y }) → γ₁ σ.snd) ((a : α) → γ₂ a)

A family of equivalences ∀ a, γ₁ a ≃ γ₂ a generates an equivalence between the product over the fibers of a function f : α → β on index types.

Equations
Instances For
    @[simp]
    theorem Equiv.piCongrSigmaFiber_apply {α : Type u_1} {β : Type u_2} {f : αβ} {γ₁ : αSort u_3} {γ₂ : αSort u_4} (e : (a : α) → γ₁ a γ₂ a) (g : (σ : (y : β) × { x : α // f x = y }) → γ₁ σ.snd) (a : α) :
    (piCongrSigmaFiber e) g a = (e a) (g f a, a, )
    @[simp]
    theorem Equiv.piCongrSigmaFiber_symm_apply {α : Type u_1} {β : Type u_2} {f : αβ} {γ₁ : αSort u_3} {γ₂ : αSort u_4} (e : (a : α) → γ₁ a γ₂ a) (g : (a : α) → γ₂ a) (σ : (y : β) × { x : α // f x = y }) :
    (piCongrSigmaFiber e).symm g σ = (e σ.snd).symm (g σ.snd)
    def Equiv.piCongrFiberwise {α : Type u_1} {β : Type u_2} {γ₁ : αType u_3} {γ₂ : βType u_4} {f : αβ} (e : (b : β) → ((σ : { a : α // f a = b }) → γ₁ σ) γ₂ b) :
    ((a : α) → γ₁ a) ((b : β) → γ₂ b)

    Let f : α → β be a function on index types. A family of equivalences, indexed by b : β, between the product over the fiber of b under f given as ∀ (σ : { a : α // f a = b }) → γ₁ σ.1) ≃ γ₂ b lifts to an equivalence over the products ∀ a, γ₁ a ≃ ∀ b, γ₂ b.

    Equations
    • One or more equations did not get rendered due to their size.
    Instances For
      @[simp]
      theorem Equiv.piCongrFiberwise_apply {α : Type u_1} {β : Type u_2} {γ₁ : αType u_3} {γ₂ : βType u_4} {f : αβ} (e : (b : β) → ((σ : { a : α // f a = b }) → γ₁ σ) γ₂ b) (g : (a : α) → γ₁ a) (b : β) :
      (piCongrFiberwise e) g b = (e b) fun (σ : { a : α // f a = b }) => g σ
      @[simp]
      theorem Equiv.piCongrFiberwise_symm_apply {α : Type u_1} {β : Type u_2} {γ₁ : αType u_3} {γ₂ : βType u_4} {f : αβ} (e : (b : β) → ((σ : { a : α // f a = b }) → γ₁ σ) γ₂ b) (g : (b : β) → γ₂ b) (a : α) :
      (piCongrFiberwise e).symm g a = (e (f a)).symm (g (f a)) a,