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import OAI.LinearAlgebra.MatrixMultiplication.JointExtraction.Hashing
import OAI.LinearAlgebra.MatrixMultiplication.JointExtraction.LossCounts
namespace OAI
/-! Joint tensor extraction, compatibility and entropy estimates. -/
noncomputable section
namespace MatrixMultiplication.JointCoarseHashing
attribute [local instance] Classical.propDecidable
abbrev Word (P : Type*) := P → Fin 17
abbrev Triple (P : Type*) := Word P × Word P × Word P
variable {P : Type*}
def HasSupportSum (S : P → ℕ) (e : Triple P) : Prop :=
∀ p, (e.1 p).val + (e.2.1 p).val + (e.2.2 p).val = S p
theorem eq_of_shared_xy (S : P → ℕ) (e f : Triple P)
(he : HasSupportSum S e) (hf : HasSupportSum S f)
(hx : e.1 = f.1) (hy : e.2.1 = f.2.1) : e = f := by
have hz : e.2.2 = f.2.2 := by
funext p
apply Fin.ext
have he' := he p
have hf' := hf p
rw [hx, hy] at he'
omega
exact Prod.ext hx (Prod.ext hy hz)
theorem eq_of_shared_xz (S : P → ℕ) (e f : Triple P)
(he : HasSupportSum S e) (hf : HasSupportSum S f)
(hx : e.1 = f.1) (hz : e.2.2 = f.2.2) : e = f := by
have hy : e.2.1 = f.2.1 := by
funext p
apply Fin.ext
have he' := he p
have hf' := hf p
rw [hx, hz] at he'
omega
exact Prod.ext hx (Prod.ext hy hz)
theorem eq_of_shared_yz (S : P → ℕ) (e f : Triple P)
(he : HasSupportSum S e) (hf : HasSupportSum S f)
(hy : e.2.1 = f.2.1) (hz : e.2.2 = f.2.2) : e = f := by
have hx : e.1 = f.1 := by
funext p
apply Fin.ext
have he' := he p
have hf' := hf p
rw [hy, hz] at he'
omega
exact Prod.ext hx (Prod.ext hy hz)
def castWord (k : ℕ) (w : Word P) : P → ZMod (37 ^ k) :=
fun p => (w p).val
def twoUnit (k : ℕ) : (ZMod (37 ^ k))ˣ :=
(JointHashing.small_nat_isUnit k 2 (by decide) (by decide)).unit
theorem twoUnit_coe (k : ℕ) : (twoUnit k : ZMod (37 ^ k)) = 2 := by
exact (JointHashing.small_nat_isUnit k 2 (by decide) (by decide)).unit_spec
theorem supportSum_cast (k : ℕ) (S : P → ℕ) (e : Triple P)
(he : HasSupportSum S e) :
castWord k e.1 + castWord k e.2.1 + castWord k e.2.2 =
fun p => (S p : ZMod (37 ^ k)) := by
funext p
have h := congrArg (fun n : ℕ => (n : ZMod (37 ^ k))) (he p)
simpa only [Nat.cast_add, Pi.add_apply, castWord] using h
theorem shared_z_cast_sum (k : ℕ) (S : P → ℕ) (e f : Triple P)
(he : HasSupportSum S e) (hf : HasSupportSum S f)
(hz : f.2.2 = e.2.2) :
castWord k f.1 + castWord k f.2.1 = castWord k e.1 + castWord k e.2.1 := by
have h := (supportSum_cast k S f hf).trans (supportSum_cast k S e he).symm
rw [hz] at h
exact add_right_cancel h
section FiniteHashing
variable [Fintype P]
abbrev Sample (P : Type*) (k : ℕ) := JointHashing.Sample P (ZMod (37 ^ k))
def Survives (k : ℕ) (U : Finset (ZMod (37 ^ k))) (e : Triple P) (s : Sample P k) : Prop :=
JointHashing.Survives (U : Set (ZMod (37 ^ k))) (castWord k e.1) (castWord k e.2.1) s
theorem full_survival_iff (k : ℕ) (U : Finset (ZMod (37 ^ k)))
(hAP : ∀ x ∈ U, ∀ y ∈ U, ∀ z ∈ U, x + y = 2 * z → x = z ∧ y = z)
(S : P → ℕ) (e : Triple P) (he : HasSupportSum S e) (s : Sample P k) :
(JointHashing.xHash s (castWord k e.1) ∈ U ∧
JointHashing.yHash s (castWord k e.2.1) ∈ U ∧
JointHashing.zHash (twoUnit k) s (fun p => (S p : ZMod (37 ^ k)))
(castWord k e.2.2) ∈ U) ↔ Survives k U e s := by
exact JointHashing.full_survival_iff (twoUnit k) (twoUnit_coe k)
(U : Set (ZMod (37 ^ k))) hAP s (castWord k e.1) (castWord k e.2.1)
(castWord k e.2.2) (fun p => (S p : ZMod (37 ^ k))) (supportSum_cast k S e he)
theorem survival_card (k : ℕ) (U : Finset (ZMod (37 ^ k))) (e : Triple P) :
Fintype.card {s : Sample P k // Survives k U e s} =
(37 ^ k) ^ Fintype.card P * U.card := by
have h := JointHashing.survival_card U (castWord k e.1) (castWord k e.2.1)
simp only [Survives, ZMod.card] at h ⊢
refine Eq.trans ?_ h
exact Fintype.card_congr (Equiv.refl _)
theorem shared_x_card_mul (k : ℕ) (U : Finset (ZMod (37 ^ k)))
(S : P → ℕ) (e f : Triple P) (he : HasSupportSum S e) (hf : HasSupportSum S f)
(hne : f ≠ e) (hx : f.1 = e.1) :
(37 ^ k) * Fintype.card {s : Sample P k // Survives k U e s ∧ Survives k U f s} =
Fintype.card {s : Sample P k // Survives k U e s} := by
classical
have hy : f.2.1 ≠ e.2.1 := fun hy => hne (eq_of_shared_xy S f e hf he hx hy)
obtain ⟨i, hi⟩ := JointHashing.coarse_words_unit_coordinate k f.2.1 e.2.1 hy
have h := JointHashing.shared_x_collision_card_mul U (castWord k e.1)
(castWord k e.2.1) (castWord k f.2.1) i hi.unit hi.unit_spec.symm
simp only [Survives, hx, ZMod.card] at h ⊢
refine Eq.trans ?_ (Eq.trans h ?_)
· exact congrArg (fun n : ℕ => 37 ^ k * n) (Fintype.card_congr (Equiv.refl _))
· exact Fintype.card_congr (Equiv.refl _)
theorem shared_y_card_mul (k : ℕ) (U : Finset (ZMod (37 ^ k)))
(S : P → ℕ) (e f : Triple P) (he : HasSupportSum S e) (hf : HasSupportSum S f)
(hne : f ≠ e) (hy : f.2.1 = e.2.1) :
(37 ^ k) * Fintype.card {s : Sample P k // Survives k U e s ∧ Survives k U f s} =
Fintype.card {s : Sample P k // Survives k U e s} := by
classical
have hx : f.1 ≠ e.1 := fun hx => hne (eq_of_shared_xy S f e hf he hx hy)
obtain ⟨i, hi⟩ := JointHashing.coarse_words_unit_coordinate k f.1 e.1 hx
have h := JointHashing.shared_y_collision_card_mul U (castWord k e.1)
(castWord k f.1) (castWord k e.2.1) i hi.unit hi.unit_spec.symm
simp only [Survives, hy, ZMod.card] at h ⊢
refine Eq.trans ?_ (Eq.trans h ?_)
· exact congrArg (fun n : ℕ => 37 ^ k * n) (Fintype.card_congr (Equiv.refl _))
· exact Fintype.card_congr (Equiv.refl _)
theorem shared_z_card_mul (k : ℕ) (U : Finset (ZMod (37 ^ k)))
(S : P → ℕ) (e f : Triple P) (he : HasSupportSum S e) (hf : HasSupportSum S f)
(hne : f ≠ e) (hz : f.2.2 = e.2.2) :
(37 ^ k) * Fintype.card {s : Sample P k // Survives k U e s ∧ Survives k U f s} =
Fintype.card {s : Sample P k // Survives k U e s} := by
classical
have hx : f.1 ≠ e.1 := fun hx => hne (eq_of_shared_xz S f e hf he hx hz)
obtain ⟨i, hi⟩ := JointHashing.coarse_words_unit_coordinate k f.1 e.1 hx
have h := JointHashing.shared_z_collision_card_mul (twoUnit k) (twoUnit_coe k)
U (castWord k e.1) (castWord k f.1) (castWord k e.2.1) (castWord k f.2.1)
(shared_z_cast_sum k S e f he hf hz) i hi.unit hi.unit_spec.symm
simp only [Survives, ZMod.card] at h ⊢
refine Eq.trans ?_ (Eq.trans h ?_)
· exact congrArg (fun n : ℕ => 37 ^ k * n) (Fintype.card_congr (Equiv.refl _))
· exact Fintype.card_congr (Equiv.refl _)
def SharesSide (e f : Triple P) : Prop :=
f.1 = e.1 ∨ f.2.1 = e.2.1 ∨ f.2.2 = e.2.2
theorem pair_survival_card_mul (k : ℕ) (U : Finset (ZMod (37 ^ k)))
(S : P → ℕ) (e f : Triple P) (he : HasSupportSum S e) (hf : HasSupportSum S f)
(hne : f ≠ e) (hshare : SharesSide e f) :
(37 ^ k) * Fintype.card {s : Sample P k // Survives k U e s ∧ Survives k U f s} =
Fintype.card {s : Sample P k // Survives k U e s} := by
rcases hshare with hx | hy | hz
· exact shared_x_card_mul k U S e f he hf hne hx
· exact shared_y_card_mul k U S e f he hf hne hy
· exact shared_z_card_mul k U S e f he hf hne hz
def ownEvent (k : ℕ) (U : Finset (ZMod (37 ^ k))) (e : Triple P) : Finset (Sample P k) :=
Finset.univ.filter (Survives k U e)
theorem ownEvent_card (k : ℕ) (U : Finset (ZMod (37 ^ k))) (e : Triple P) :
(ownEvent k U e).card = (37 ^ k) ^ Fintype.card P * U.card := by
simpa only [ownEvent, Fintype.card_subtype] using survival_card k U e
theorem pair_event_card_mul (k : ℕ) (U : Finset (ZMod (37 ^ k)))
(S : P → ℕ) (e f : Triple P) (he : HasSupportSum S e) (hf : HasSupportSum S f)
(hne : f ≠ e) (hshare : SharesSide e f) :
(37 ^ k) * ((ownEvent k U e).filter (Survives k U f)).card = (ownEvent k U e).card := by
simpa only [ownEvent, Finset.filter_filter, Fintype.card_subtype] using
pair_survival_card_mul k U S e f he hf hne hshare
theorem competitor_union_card_mul_le (k : ℕ) (U : Finset (ZMod (37 ^ k)))
(S : P → ℕ) (e : Triple P) (he : HasSupportSum S e) (competitors : Finset (Triple P))
(hf : ∀ f ∈ competitors, HasSupportSum S f)
(hne : ∀ f ∈ competitors, f ≠ e)
(hshare : ∀ f ∈ competitors, SharesSide e f) :
(37 ^ k) * ((ownEvent k U e).filter
(fun s => ∃ f ∈ competitors, Survives k U f s)).card ≤
competitors.card * (ownEvent k U e).card := by
apply JointLossCounts.competitor_union_card_mul_le
intro f hf'
exact (pair_event_card_mul k U S e f he (hf f hf') (hne f hf') (hshare f hf')).le
theorem competitor_union_card_le (k : ℕ) (U : Finset (ZMod (37 ^ k)))
(S : P → ℕ) (e : Triple P) (he : HasSupportSum S e) (competitors : Finset (Triple P))
(hf : ∀ f ∈ competitors, HasSupportSum S f)
(hne : ∀ f ∈ competitors, f ≠ e)
(hshare : ∀ f ∈ competitors, SharesSide e f) :
(((ownEvent k U e).filter (fun s => ∃ f ∈ competitors, Survives k U f s)).card : ℝ) ≤
((competitors.card : ℝ) / ((37 ^ k : ℕ) : ℝ)) * ((ownEvent k U e).card : ℝ) := by
have hM : (0 : ℝ) < ((37 ^ k : ℕ) : ℝ) := by
exact_mod_cast (pow_pos (by decide : 0 < (37 : ℕ)) k)
have h := competitor_union_card_mul_le k U S e he competitors hf hne hshare
have hR : ((37 ^ k : ℕ) : ℝ) *
(((ownEvent k U e).filter (fun s => ∃ f ∈ competitors, Survives k U f s)).card : ℝ) ≤
(competitors.card : ℝ) * ((ownEvent k U e).card : ℝ) := by exact_mod_cast h
rw [div_mul_eq_mul_div]
exact (le_div_iff₀ hM).2 (by simpa only [mul_comm] using hR)
theorem pair_survival_fraction (k : ℕ) (U : Finset (ZMod (37 ^ k))) (hU : U.Nonempty)
(S : P → ℕ) (e f : Triple P) (he : HasSupportSum S e) (hf : HasSupportSum S f)
(hne : f ≠ e) (hshare : SharesSide e f) :
(((ownEvent k U e).filter (Survives k U f)).card : ℝ) / ((ownEvent k U e).card : ℝ) =
1 / ((37 ^ k : ℕ) : ℝ) := by
have hM : (0 : ℕ) < 37 ^ k := pow_pos (by decide) k
have hS : 0 < (ownEvent k U e).card := by
rw [ownEvent_card]
exact Nat.mul_pos (pow_pos hM _) (Finset.card_pos.mpr hU)
apply (div_eq_div_iff (by exact_mod_cast Nat.ne_of_gt hS)
(by exact_mod_cast Nat.ne_of_gt hM)).2
have h := congrArg (fun n : ℕ => (n : ℝ)) (pair_event_card_mul k U S e f he hf hne hshare)
simpa only [Nat.cast_mul, one_mul, mul_comm] using h
end FiniteHashing
end MatrixMultiplication.JointCoarseHashing
end
end OAI