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Add lean source and binary files (part 62)
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import Mathlib.LinearAlgebra.Dimension.Finrank
import OAI.Computability.PerfectCompleteness.Algebra.EvaluationMatrix
import OAI.Computability.PerfectCompleteness.Algebra.UniformLinearImage
import OAI.Computability.PerfectCompleteness.Foundations.HierarchicalArrays
namespace OAI
namespace PerfectCompleteness.NodeEmbedding
open TreeSourceSpaces HierarchicalArrays
open UniqueGamesTheorem.Foundations.Games
open scoped Classical
noncomputable section
variable {branch : Nat → Nat} {n t : Nat}
abbrev NumberedDomain (slots : RecursiveSpaces.Slots branch n → Fin t → MixedSupport.Slot) :=
MixedSupport.Assignment (TreeCanonical.numberedSlots slots)
abbrev NodeH (slots : RecursiveSpaces.Slots branch n → Fin t → MixedSupport.Slot)
(node : Nodes branch n) := H (nodeSlots slots node)
variable (slots : RecursiveSpaces.Slots branch n → Fin t → MixedSupport.Slot)
(node : Nodes branch n)
def numberedRestriction : NumberedDomain slots → Domain (nodeSlots slots node) :=
restrictNode slots node ∘ (TreeCanonical.assignmentEquiv slots).symm
theorem numberedRestriction_surjective : Function.Surjective (numberedRestriction slots node) :=
(restrictNode_surjective slots node).comp (TreeCanonical.assignmentEquiv slots).symm.surjective
theorem pullback_injective :
Function.Injective (PointwiseSpaces.pullback F2 (numberedRestriction slots node)) :=
PointwiseSpaces.pullback_injective _ (numberedRestriction_surjective slots node)
def RowSpace : Submodule F2 (NumberedDomain slots → F2) :=
(NodeH slots node).map (PointwiseSpaces.pullback F2 (numberedRestriction slots node))
def equiv : NodeH slots node ≃ₗ[F2] RowSpace slots node :=
Submodule.equivMapOfInjective
(PointwiseSpaces.pullback F2 (numberedRestriction slots node))
(pullback_injective slots node) (NodeH slots node)
def embed : NodeH slots node →ₗ[F2] RowSpace slots node :=
(equiv slots node).toLinearMap
@[simp] theorem equiv_apply (f : NodeH slots node) (x : NumberedDomain slots) :
(equiv slots node f).val x = f.val (numberedRestriction slots node x) := rfl
@[simp] theorem embed_apply (f : NodeH slots node) (x : NumberedDomain slots) :
(embed slots node f).val x = f.val (numberedRestriction slots node x) := rfl
theorem embed_injective : Function.Injective (embed slots node) :=
(equiv slots node).injective
theorem embed_surjective : Function.Surjective (embed slots node) :=
(equiv slots node).surjective
theorem finrank_eq :
Module.finrank F2 (RowSpace slots node) = Module.finrank F2 (NodeH slots node) :=
(equiv slots node).finrank_eq.symm
theorem card_eq : Nat.card (RowSpace slots node) = Nat.card (NodeH slots node) :=
(Nat.card_congr (equiv slots node).toEquiv).symm
theorem uniform_embed [Fintype (NodeH slots node)] [Fintype (RowSpace slots node)] :
(FiniteDistribution.uniform (NodeH slots node)).pushforward (embed slots node) =
FiniteDistribution.uniform (RowSpace slots node) :=
UniformLinearImage.uniform_pushforward_linearMap (embed slots node)
(embed_surjective slots node)
def rowsEquiv (ℓ : Nat) :
(Fin ℓ → NodeH slots node) ≃ₗ[F2] (Fin ℓ → RowSpace slots node) :=
LinearEquiv.piCongrRight (fun _ : Fin ℓ => equiv slots node)
@[simp] theorem rowsEquiv_apply (ℓ : Nat) (f : Fin ℓ → NodeH slots node) (i : Fin ℓ) :
rowsEquiv slots node ℓ f i = embed slots node (f i) := rfl
theorem uniform_rowsEquiv (ℓ : Nat)
[Fintype (NodeH slots node)] [Fintype (RowSpace slots node)] :
(FiniteDistribution.uniform (Fin ℓ → NodeH slots node)).pushforward
(rowsEquiv slots node ℓ) =
FiniteDistribution.uniform (Fin ℓ → RowSpace slots node) :=
UniformLinearImage.uniform_pushforward_linearMap
(rowsEquiv slots node ℓ).toLinearMap (rowsEquiv slots node ℓ).surjective
theorem squareSpace_eq :
PointwiseSpaces.squareSpace (RowSpace slots node) =
(PointwiseSpaces.squareSpace (NodeH slots node)).map
(PointwiseSpaces.pullback F2 (numberedRestriction slots node)) :=
(PointwiseSpaces.squareSpace_map_pullback
(numberedRestriction slots node) (NodeH slots node)).symm
theorem embed_mul (f g : NodeH slots node) :
(embed slots node f).val * (embed slots node g).val =
PointwiseSpaces.pullback F2 (numberedRestriction slots node) (f.val * g.val) := rfl
def RootRowSpace : Submodule F2 (NumberedDomain slots → F2) :=
(H slots).map (PointwiseSpaces.pullback F2 (TreeCanonical.assignmentEquiv slots).symm)
theorem rowSpace_le_root (hbranch : ∀ k < n, 0 < branch k) :
RowSpace slots node ≤ RootRowSpace slots := by
intro f hf
obtain ⟨g, hg, rfl⟩ := Submodule.mem_map.mp hf
have hroot : PointwiseSpaces.pullback F2 (restrictNode slots node) g ∈ H slots :=
DescendantSpaces.space_descendant_le (Nodes.path node) (LeafDomain slots) hbranch
(Submodule.mem_map_of_mem hg)
exact Submodule.mem_map.mpr
⟨PointwiseSpaces.pullback F2 (restrictNode slots node) g, hroot, rfl⟩
theorem squareSpace_le_root (hbranch : ∀ k < n, 0 < branch k)
(hproper : Nodes.height node < n) :
PointwiseSpaces.squareSpace (RowSpace slots node) ≤ RootRowSpace slots := by
rw [squareSpace_eq]
intro f hf
obtain ⟨g, hg, rfl⟩ := Submodule.mem_map.mp hf
have hroot : PointwiseSpaces.pullback F2 (restrictNode slots node) g ∈ H slots :=
DescendantSpaces.descendant_square_le_space (Nodes.path node) (LeafDomain slots)
hbranch hproper (Submodule.mem_map_of_mem hg)
exact Submodule.mem_map.mpr
⟨PointwiseSpaces.pullback F2 (restrictNode slots node) g, hroot, rfl⟩
variable {slots} {rows : Nat → Nat}
def embeddedRows (arrays : Arrays slots rows) (node : Nodes branch n) :
Fin (rows (Nodes.height node)) → RowSpace slots node :=
fun i => embed slots node (arrays node i)
@[simp] theorem embeddedRows_apply (arrays : Arrays slots rows) (node : Nodes branch n)
(i : Fin (rows (Nodes.height node))) (x : NumberedDomain slots) :
(embeddedRows arrays node i).val x =
(TreeCanonical.numberedFunction slots (fullJoint arrays) x).1 node i := rfl
def matrix (arrays : Arrays slots rows) (node : Nodes branch n) :
Module.Dual F2 (RowSpace slots node) →ₗ[F2] Block rows node :=
EvaluationMatrix.ofRows (RowSpace slots node) (embeddedRows arrays node)
@[simp] theorem matrix_evaluate (arrays : Arrays slots rows) (node : Nodes branch n)
(x : NumberedDomain slots) :
EvaluationMatrix.evaluate (RowSpace slots node) (matrix arrays node) x =
(TreeCanonical.numberedFunction slots (fullJoint arrays) x).1 node := rfl
theorem evaluation_comp_embed (x : NumberedDomain slots) :
(EvaluationMatrix.evaluation (RowSpace slots node) x).comp (embed slots node) =
EvaluationMatrix.evaluation (NodeH slots node) (numberedRestriction slots node x) := by
ext f
rfl
end
end PerfectCompleteness.NodeEmbedding
end OAI