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Add lean source and binary files (part 42)
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import OAI.Combinatorics.ContingencyTables.Transport.ContextWeightedEnumeration
import OAI.Combinatorics.ContingencyTables.Sampling.PhysicalPrefixEnergies
import OAI.Combinatorics.ContingencyTables.Transport.FiniteChoiceFibres
namespace OAI
/-! # Literal finite choice fibres equal the transport child sums -/
namespace ContingencyTables.SmallContextEnumeration
open scoped BigOperators Classical
open SmallContextCoordinates SmallContextFibres PhysicalCompletionFibres
open LargePairEnumeration BalancedEnumeration BalancedFamily
open FirstPaperContextTransport FirstPaperPhysicalMarginal ExcessContextProfiles SmallGraphProfiles
open FiniteExposureVariance
open IntegerWeightedTransport
universe u
variable {I J : Type u} [Fintype I] [Fintype J] [LinearOrder I] [LinearOrder J]
def rawChoice (small : I → J → Bool) (U : ℕ) (x : Cells small → Fin (U+1)) :
SmallProfile small := fun p => if p.2 then U-(x p.1).val else (x p.1).val
def earlierChoices (small : I → J → Bool) (s : I×J) (U : ℕ)
(x : Cells small → Fin (U+1)) : Earlier small s → Fin (U+1) := fun a => x a.val
omit [Fintype I] [Fintype J] in
lemma earlierChoices_eq_iff (small : I → J → Bool) (s : I×J) (U : ℕ)
(x : Cells small → Fin (U+1)) (τ : Earlier small s → Fin (U+1)) :
earlierChoices small s U x=τ ↔ ∀ a : Earlier small s,x a.val=τ a :=
funext_iff
def ChoiceContext (small : I → J → Bool) (s : I×J) (hs : small s.1 s.2=true) (U : ℕ)
(τ : Earlier small s → Fin (U+1)) (k : Fin (U+1)) :=
{x : Cells small → Fin (U+1) // earlierChoices small s U x=τ ∧ x ⟨s,hs⟩=k}
noncomputable instance choiceContextFintype (small : I → J → Bool) (s : I×J)
(hs : small s.1 s.2=true) (U : ℕ) (τ : Earlier small s → Fin (U+1)) (k : Fin (U+1)) :
Fintype (ChoiceContext small s hs U τ k) := by unfold ChoiceContext; infer_instance
noncomputable def choiceContextEquiv (small : I → J → Bool) (s : I×J)
(hs : small s.1 s.2=true) (U : ℕ) (τ : Earlier small s → Fin (U+1)) (k : Fin (U+1)) :
(Later small s → Fin (U+1)) ≃ ChoiceContext small s hs U τ k where
toFun y := ⟨splitChoices small s hs U τ k y,funext (splitChoices_prefix small s hs U τ k y),
splitChoices_special small s hs U τ k y⟩
invFun x := fun a => x.val a.val
left_inv y := by funext a; exact splitChoices_later small s hs U τ k y a
right_inv x := by
apply Subtype.ext
funext a
obtain ⟨v,rfl⟩ := (cellSplitEquiv small s hs).surjective a
rcases v with p|(_|t)
· exact (splitChoices_prefix small s hs U τ k _ p).trans (congrFun x.property.1 p).symm
· exact (splitChoices_special small s hs U τ k _).trans x.property.2.symm
· exact splitChoices_later small s hs U τ k _ t
lemma choice_fibre_sum (small : I → J → Bool) (s : I×J) (hs : small s.1 s.2=true)
(U : ℕ) (τ : Earlier small s → Fin (U+1)) (k : Fin (U+1))
(F : (Cells small → Fin (U+1)) → ℝ) :
(∑ x,fibreWeight (fibreWeight F (earlierChoices small s U) τ) (fun x => x ⟨s,hs⟩) k x)=
∑ x : ChoiceContext small s hs U τ k,F x.val := by
exact double_fibre_sum F (earlierChoices small s U) (fun x => x ⟨s,hs⟩) τ k
omit [Fintype I] [Fintype J] in
lemma prefixChoices_extension (small : I → J → Bool) (s : I×J) (U : ℕ)
(τ : Earlier small s → Fin (U+1)) :
prefixChoices small s (prefixExtension small s U τ) U (prefixExtension_bounded small s U τ)=τ := by
funext a
apply Fin.ext
exact prefixExtension_at small s U τ a
/-- The child mass and every child moment are the actual finite fibre
sums of balanced physical choices, retaining all large completions. -/
theorem eliminate_context_eq_choice_fibre (small : I → J → Bool) (B : I → J → ℕ)
(s : I×J) (hs : small s.1 s.2=true) (U : ℕ)
(hB : ∀ i j,small i j=true → B i j=U)
(τ : Earlier small s → Fin (U+1)) (k : Fin (U+1))
{n : ℕ} (e : Fin n ≃ Later small s) (F : SmallProfile small → ℝ) :
eliminate (widths (fun _ : Fin n => U))
(fun p => F (assemble small s hs (prefixExtension small s U τ) U e p)) (childProfile U k.val)=
∑ x,fibreWeight (fibreWeight (fun x => F (rawChoice small U x))
(earlierChoices small s U) τ) (fun x => x ⟨s,hs⟩) k x := by
rw [eliminate_context_eq_weighted_sum small B s hs _ U hB
(prefixExtension_bounded small s U τ),choice_fibre_sum]
have he := Fintype.sum_equiv
(balancedContextEquiv small B s hs (prefixExtension small s U τ) U hB
(prefixExtension_bounded small s U τ) k)
(fun y => F (rawChoice small U (splitChoices small s hs U τ k y)))
(fun z => F (naturalProfile z.val)) (fun y => by
change F (rawChoice small U (splitChoices small s hs U τ k y))=
F (rawChoice small U (splitChoices small s hs U
(prefixChoices small s (prefixExtension small s U τ) U (prefixExtension_bounded small s U τ)) k y))
rw [prefixChoices_extension])
have hc := Fintype.sum_equiv (choiceContextEquiv small s hs U τ k)
(fun y => F (rawChoice small U (splitChoices small s hs U τ k y)))
(fun x => F (rawChoice small U x.val)) (fun _ => rfl)
exact he.symm.trans hc
end ContingencyTables.SmallContextEnumeration
end OAI