roseking's picture
Add lean source and binary files (part 119)
9b6e014 verified
Raw History Blame Contribute Delete
3.03 kB
import Mathlib
import OAI.Probability.BinarySweep.MatrixBounds.CenteredMatrix
namespace OAI
noncomputable section
open scoped BigOperators Classical
namespace BinaryCoordinateSweeps.Young
variable {I J X Y : Type*} [Fintype I] [DecidableEq I] [Fintype J] [DecidableEq J]
[Fintype X] [DecidableEq X] [Fintype Y] [DecidableEq Y]
omit [Fintype I] [DecidableEq I] [Fintype X] [DecidableEq X] in
lemma partialKernel_iff (A : Finset I) (g : Equiv.Perm X) (x y : I ↪ X) :
subPlacement A (movePlacement g x)=subPlacement A y ↔ ∀i∈A, g (x i)=y i := by
constructor
· intro h i hi
exact congrArg (fun u => u ⟨i,hi⟩) h
· intro h
apply Function.Embedding.ext
intro i
exact h i.val i.property
omit [Fintype I] [DecidableEq I] [Fintype J] [DecidableEq J] [Fintype X] [Fintype Y] in
lemma partialKernel_reindex (a : I ≃ J) (e : X ≃ Y) (A : Finset I)
(g : Equiv.Perm X) (x y : I ↪ X) :
partialKernel (a.finsetCongr A) (e.permCongr g)
(Equiv.embeddingCongr a e y) (Equiv.embeddingCongr a e x)=partialKernel A g y x := by
unfold partialKernel
congr 1
rw [partialKernel_iff,partialKernel_iff]
apply propext
constructor
· intro he i hi
have ht := he (a i) (by simpa using hi)
simpa using ht
· intro he j hj
obtain ⟨i,rfl⟩ := a.surjective j
have ht := he i (by simpa using hj)
simpa using congrArg e ht
omit [DecidableEq I] [DecidableEq J] in
theorem centeredMatrix_reindex (a : I ≃ J) (e : X ≃ Y) (s : ℝ)
(p : Equiv.Perm X → ℂ) (x y : I ↪ X) :
centeredMatrix s (fun g => p (e.permCongr.symm g))
(Equiv.embeddingCongr a e y) (Equiv.embeddingCongr a e x)=centeredMatrix s p y x := by
simp only [centeredMatrix,Finset.powerset_univ,Matrix.sum_apply,Matrix.smul_apply,smul_eq_mul]
have ht := Equiv.sum_comp a.finsetCongr (fun A : Finset J =>
((-1:ℂ)^(Fintype.card J-A.card)*(s:ℂ)^A.card/(s:ℂ)^Fintype.card J) *
∑g, p (e.permCongr.symm g) * partialKernel A g
(Equiv.embeddingCongr a e y) (Equiv.embeddingCongr a e x))
rw [← ht]
apply Finset.sum_congr rfl
intro A _
have hc : (a.finsetCongr A).card=A.card := by simp
rw [hc,← Fintype.card_congr a]
congr 1
have hu := Equiv.sum_comp e.permCongr (fun g =>
p (e.permCongr.symm g) * partialKernel (a.finsetCongr A) g
(Equiv.embeddingCongr a e y) (Equiv.embeddingCongr a e x))
rw [← hu]
apply Finset.sum_congr rfl
intro g _
rw [Equiv.symm_apply_apply,partialKernel_reindex]
omit [DecidableEq I] [DecidableEq J] in
lemma centeredMatrix_hs_reindex (a : I ≃ J) (e : X ≃ Y) (s : ℝ)
(p : Equiv.Perm X → ℂ) :
(∑x : J ↪ Y, ∑y, ‖centeredMatrix s (fun g => p (e.permCongr.symm g)) y x‖^2)=
∑x : I ↪ X, ∑y, ‖centeredMatrix s p y x‖^2 := by
rw [← Equiv.sum_comp (Equiv.embeddingCongr a e)]
apply Finset.sum_congr rfl
intro x _
rw [← Equiv.sum_comp (Equiv.embeddingCongr a e)]
simp_rw [centeredMatrix_reindex]
end BinaryCoordinateSweeps.Young
end
end OAI