openAI-math-dataset / lean /OAI /SetTheory /PartitionPrinciple /Transfinite /AmalgamationCoinitiality.lean
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Sync from openai/math@faee2cf485a8 (part 25)
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import OAI.SetTheory.PartitionPrinciple.Forcing.ChronologicalTransport
namespace OAI
section
namespace PartitionPilot.Compression.RecursiveMaps.PrincipalAmalgamation.Input
open Attachment Chronological
universe u
variable {A B Stage : Type u} [LinearOrder Stage]
{P : MeetOrder A} {Q : MeetOrder B} (g : Input P Q)
def birth (oldBirth : A → Stage) (s : Stage) : g.Node → Stage
| .inl a => oldBirth a
| .inr _ => s
theorem birth_le (oldBirth : A → Stage) (s : Stage) (old : ∀ a, oldBirth a < s) :
∀ x, g.birth oldBirth s x ≤ s := by
intro x
cases x with
| inl a => exact le_of_lt (old a)
| inr _ => exact le_refl s
theorem old_meet_preserved (oldBirth : A → Stage) (s : Stage)
(old : ∀ a, oldBirth a < s) (previous : OldMeet (P := P) oldBirth) :
OldMeet (P := g.order) (g.birth oldBirth s) := by
intro x y earlier notLower
cases x with
| inl a =>
cases y with
| inl b =>
have eq : g.order.meet (.inl a) (.inl b) = Sum.inl (P.meet a b) :=
(g.left.map_meet a b).symm
rw [eq]
exact previous a b earlier notLower
| inr y => exact False.elim (lt_asymm earlier (old a))
| inr x =>
cases y with
| inl a =>
rw [g.new_shadow_meet]
exact old _
| inr y => exact False.elim (lt_irrefl s earlier)
noncomputable def earlier_layer {Space : Stage → Type u}
{order : ∀ t, MeetOrder (Space t)} (oldBirth : A → Stage) (s t : Stage)
(earlier : t < s) (layer : GrowthLayer Space order P oldBirth t) :
GrowthLayer Space order g.order (g.birth oldBirth s) t := by
apply layer.transport g.left (fun _ => rfl)
intro x hx
cases x with
| inl a => exact ⟨a, rfl⟩
| inr x =>
change s = t at hx
exact False.elim (lt_irrefl s (hx ▸ earlier))
noncomputable def incoming_layer (Space : Stage → Type u)
(order : ∀ t, MeetOrder (Space t)) (oldBirth : A → Stage) (s : Stage)
(old : ∀ a, oldBirth a < s) (I : Type u) [Countable I]
(index : I → Stage) (earlier : ∀ i, index i < s)
(copy : ∀ i, MeetEmbedding (order (index i)) Q)
(cover : ∀ b, ∃ i y, (copy i).toFun y = b) :
GrowthLayer Space order g.order (g.birth oldBirth s) s := by
apply GrowthLayer.copies I inferInstance index earlier (fun i => compose (copy i) g.right)
intro x hx
cases x with
| inl a =>
change oldBirth a = s at hx
exact False.elim (lt_irrefl s (hx ▸ old a))
| inr b =>
rcases cover b.val with ⟨i, y, eq⟩
exact ⟨i, y, (congrArg g.right.toFun eq).trans (g.represent_new b.val b.property)⟩
theorem profile_persists (c e K : A) (F : A → Prop) (inhabited : ∃ f, F f)
(profile : Profile P c e K F) (separated : ¬ P.le e K) :
ProfileOver g.left c e K F :=
attachment_preserves_profile g.data g.component_meets c e K F inhabited profile separated
end PartitionPilot.Compression.RecursiveMaps.PrincipalAmalgamation.Input
namespace PartitionPilot.Compression.RecursiveMaps.PrincipalAmalgamation
open Chronological
universe u
noncomputable def binary_incoming_layer {A T Stage : Type u} [LinearOrder Stage]
{P : MeetOrder A} {R : MeetOrder T} (tile : Input R R) (g : Input P tile.order)
(Space : Stage → Type u) (order : ∀ t, MeetOrder (Space t))
(oldBirth : A → Stage) (s t : Stage) (old : ∀ a, oldBirth a < s) (earlier : t < s)
(template : MeetIso (order t) R) :
GrowthLayer Space order g.order (g.birth oldBirth s) s := by
apply g.incoming_layer Space order oldBirth s old (ULift.{u} Bool) (fun _ => t) (fun _ => earlier)
(fun i => compose template.toMeetEmbedding (BinaryTiles.vertex R tile i.down))
intro x
rcases BinaryTiles.vertex_cover R tile x with ⟨i, y, eq⟩
refine ⟨⟨i⟩, template.inverse y, ?_⟩
change (BinaryTiles.vertex R tile i).toFun (template.toFun (template.inverse y)) = x
rw [template.right_inverse]
exact eq
end PartitionPilot.Compression.RecursiveMaps.PrincipalAmalgamation
end
end OAI