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Add lean source and binary files (part 83)
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import Mathlib
import OAI.GroupTheory.SimpleAmenable.CentralCovers.BooleanCoordinateGeneration
import OAI.GroupTheory.SimpleAmenable.CentralCovers.ConditionalBooleanGeneration
namespace OAI
section
section
open scoped symmDiff
namespace SimpleAmenable
open scoped commutatorElement
open scoped commutatorElement
section FiveTrackGeneration
noncomputable def fiveTrackHom {m : ℕ} (ι : Fin 5 ↪ Fin m) :
alternatingGroup (Fin 5) →* Equiv.Perm (Fin m) :=
(Equiv.Perm.viaEmbeddingHom ι).comp (alternatingGroup (Fin 5)).subtype
instance fiveTrackPerfect : Group.IsPerfect (alternatingGroup (Fin 5)) :=
⟨commutator_alternatingGroup_eq_top (by norm_num)⟩
theorem fiveTrack_sign {m : ℕ} (ι : Fin 5 ↪ Fin m)
(g : alternatingGroup (Fin 5)) : fiveTrackHom ι g ∈ alternatingGroup (Fin m) := by
classical
change Equiv.Perm.sign (g.val.viaEmbedding ι) = 1
rw [Equiv.Perm.viaEmbedding,Equiv.Perm.sign_extendDomain]
exact g.property
theorem fiveTrack_support {m : ℕ} (ι : Fin 5 ↪ Fin m)
(g : alternatingGroup (Fin 5)) : (fiveTrackHom ι g).support.card ≤ 5 := by
classical
have hsub : (fiveTrackHom ι g).support ⊆ Finset.univ.map ι := by
intro i hi
by_contra hn
have hn' : i ∉ Set.range ι := by simpa using hn
exact (Equiv.Perm.mem_support.mp hi) (Equiv.Perm.viaEmbedding_apply_of_notMem g.val ι i hn')
simpa using Finset.card_le_card hsub
theorem fiveTrack_initial_generated (a : ℕ) (r : CutRing) (m : ℕ)
(ι : Fin 5 ↪ Fin (m+1)) (j : Fin 5) :
ConditionalAvailable (fiveTrackHom ι) (sourceGenerated a r m) (initialTest a r j) := by
intro g
exact sourceGenerator_mem_generated a r m
(Sum.inl (j,⟨fiveTrackHom ι g,fiveTrack_sign ι g,fiveTrack_support ι g⟩))
theorem fiveTrack_whole_generated (a : ℕ) (r : CutRing) (m : ℕ)
(ι : Fin 5 ↪ Fin (m+1)) :
ConditionalAvailable (fiveTrackHom ι) (sourceGenerated a r m) (wholePolygon a) :=
fiveTrack_initial_generated a r m ι 0
noncomputable def alphabetTranslation {m : ℕ} (ι : Fin 5 ↪ Fin m)
(b : Fin m) (u : CutRing × CutRing) : Fin m → CutRing × CutRing :=
∑ j : Fin 5, (Pi.single (ι j) u - Pi.single b u)
theorem alphabetTranslation_generated (a : ℕ) (r : CutRing) (m : ℕ)
(ι : Fin 5 ↪ Fin (m+1)) (b : Fin (m+1)) (u : CutRing × CutRing) :
trackTranslation (a := a) (alphabetTranslation ι b u) ∈ sourceGenerated a r m := by
classical
unfold alphabetTranslation
induction (Finset.univ : Finset (Fin 5)) using Finset.induction_on with
| empty => simp
| @insert i s hi ih =>
rw [Finset.sum_insert hi,trackTranslation_add]
exact (sourceGenerated a r m).mul_mem (balanced_difference_generated a r m b (ι i) u) ih
theorem alphabetTranslation_apply {m : ℕ} (ι : Fin 5 ↪ Fin m)
(b : Fin m) (hb : b ∉ Set.range ι) (u : CutRing × CutRing) (j : Fin 5) :
alphabetTranslation ι b u (ι j) = u := by
classical
have hb' : ∀ k, ι k ≠ b := fun k h => hb ⟨k,h⟩
simp [alphabetTranslation,Finset.sum_apply,Pi.single_apply,ι.injective.eq_iff,hb']
theorem conditional_translation_conjugate {a m : ℕ} (U : polygonAlgebra a)
(σ : Equiv.Perm (Fin m)) (d : Fin m → CutRing × CutRing) (u : CutRing × CutRing)
(hd : ∀ i, σ i ≠ i → d i = u) :
conditionalHom (⟨translate a (-u) ⁻¹' U.val,
polygon_preimage_translate (-u) U.property⟩ : polygonAlgebra a) σ =
trackTranslation d * conditionalHom U σ * (trackTranslation d)⁻¹ := by
classical
apply Subtype.ext
apply Equiv.ext
rintro ⟨i,p⟩
change conditionalPerm (⟨_,_⟩ : polygonAlgebra a) σ (i,p) =
trackTranslationPerm d (conditionalPerm U σ ((trackTranslationPerm d).symm (i,p)))
by_cases hi : σ i = i
· simp [conditionalPerm,trackTranslationPerm,hi,← translate_add]
· have hi' : σ (σ i) ≠ σ i := fun h => hi (σ.injective h)
have hdi := hd i hi
have hdsi := hd (σ i) hi'
by_cases hp : translate a (-u) p ∈ U.val <;>
simp_all [conditionalPerm,trackTranslationPerm,← translate_add]
theorem fiveTrack_translate_generated (a : ℕ) (r : CutRing) (m : ℕ)
(ι : Fin 5 ↪ Fin (m+1)) (b : Fin (m+1)) (hb : b ∉ Set.range ι)
(U : polygonAlgebra a)
(hU : ConditionalAvailable (fiveTrackHom ι) (sourceGenerated a r m) U)
(u : CutRing × CutRing) :
ConditionalAvailable (fiveTrackHom ι) (sourceGenerated a r m)
⟨translate a u ⁻¹' U.val,polygon_preimage_translate u U.property⟩ := by
intro g
let d := alphabetTranslation ι b (-u)
have hd : ∀ i, fiveTrackHom ι g i ≠ i → d i = -u := by
intro i hi
have hi' : i ∈ Set.range ι := by
by_contra hn
exact hi (Equiv.Perm.viaEmbedding_apply_of_notMem g.val ι i hn)
obtain ⟨j,rfl⟩ := hi'
exact alphabetTranslation_apply ι b hb (-u) j
have he := conditional_translation_conjugate U (fiveTrackHom ι g) d (-u) hd
simp only [neg_neg] at he
rw [he]
have ht := alphabetTranslation_generated a r m ι b (-u)
exact (sourceGenerated a r m).mul_mem ((sourceGenerated a r m).mul_mem ht (hU g))
((sourceGenerated a r m).inv_mem ht)
noncomputable def fiveTrackBoolean (a : ℕ) (r : CutRing) (m : ℕ)
(ι : Fin 5 ↪ Fin (m+1)) : BooleanSubalgebra (Set (GenericSquare a)) :=
conditionalBoolean (fiveTrackHom ι) (sourceGenerated a r m)
(fiveTrack_whole_generated a r m ι)
theorem fiveTrackBoolean_translate (a : ℕ) (r : CutRing) (m : ℕ)
(ι : Fin 5 ↪ Fin (m+1)) (b : Fin (m+1)) (hb : b ∉ Set.range ι)
(u : CutRing × CutRing) {U : Set (GenericSquare a)}
(hU : U ∈ fiveTrackBoolean a r m ι) :
translate a u ⁻¹' U ∈ fiveTrackBoolean a r m ι := by
obtain ⟨hU,hU'⟩ := hU
exact ⟨polygon_preimage_translate u hU,
fiveTrack_translate_generated a r m ι b hb ⟨U,hU⟩ hU' u⟩
theorem fiveTrackBoolean_initial (a : ℕ) (r : CutRing) (m : ℕ)
(ι : Fin 5 ↪ Fin (m+1)) (j : Fin 5) :
(initialTest a r j).val ∈ fiveTrackBoolean a r m ι :=
⟨(initialTest a r j).property,fiveTrack_initial_generated a r m ι j⟩
theorem fiveTrackBoolean_coordinate (a : ℕ) (r : CutRing) (m : ℕ)
(ι : Fin 5 ↪ Fin (m+1)) (b : Fin (m+1)) (hb : b ∉ Set.range ι)
(j : Fin 2) (z : CutRing) :
halfPlane a (Fin.castLE (by omega) j) z ∈ fiveTrackBoolean a r m ι := by
apply coordinate_cuts_generated _ j
(fun u _ hU => fiveTrackBoolean_translate a r m ι b hb u hU)
fin_cases j
· exact fiveTrackBoolean_initial a r m ι 1
· exact fiveTrackBoolean_initial a r m ι 2
end FiveTrackGeneration
end SimpleAmenable
end
end
end OAI