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Add lean source and binary files (part 47)
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import Mathlib
import OAI.Combinatorics.MatchingCount.Graphs.EnlargementRun
import OAI.Combinatorics.MatchingCount.Sampling.PairStep
namespace OAI
namespace MatchingFPRAS.Variation
open Finset
variable {Ω Ψ : Type*} [Fintype Ω] [Fintype Ψ]
lemma bind_perturbation_on (p : Ω → ℝ) (k l : Ω → Ψ → ℝ)
(hp : ∀ x,0 ≤ p x) (hs : ∑ x,p x=1) (ε : ℝ)
(he : ∀ x,p x≠0 → tv (k x) (l x) ≤ ε) :
tv (bind p k) (bind p l) ≤ ε := by
unfold tv bind
have h : ∑ y,|∑ x,p x*k x y-∑ x,p x*l x y| ≤ 2*ε := by
calc
_ = ∑ y,|∑ x,p x*(k x y-l x y)| := by simp only [mul_sub,sum_sub_distrib]
_ ≤ ∑ y,∑ x,|p x*(k x y-l x y)| := sum_le_sum (fun y _ => abs_sum_le_sum_abs _ _)
_ = ∑ x,p x*(∑ y,|k x y-l x y|) := by
rw [sum_comm]; simp_rw [abs_mul,abs_of_nonneg (hp _),←mul_sum]
_ ≤ ∑ x,p x*(2*ε) := by
apply sum_le_sum
intro x _
by_cases hx : p x=0
· simp [hx]
· apply mul_le_mul_of_nonneg_left _ (hp x)
have hh:=he x hx
unfold tv at hh
linarith
_ = _ := by rw [←sum_mul,hs,one_mul]
linarith
end MatchingFPRAS.Variation
namespace MatchingFPRAS.WeightedOptions
open Finset Variation
variable {J Ω B : Type*} [Fintype J] [DecidableEq J] [Fintype Ω] [DecidableEq Ω]
variable [Fintype B] [Nonempty B]
theorem drawThen_tv_on (c : WeightedOptions J) (g : J → B → Ω) (k : ℕ)
(P : J → Ω → ℝ) (e : ℝ) (he : ∀ j,c.law j≠0 → tv (imageLaw (g j)) (P j)≤e) :
tv (imageLaw (c.drawThen g k)) (bind (fun j=>(c.law j:ℝ)) P)≤
2*c.size/(2:ℝ)^k+e := by
rw [drawThen_law]
calc
_ ≤ tv (bind (imageLaw (c.draw k)) (fun j=>imageLaw (g j)))
(bind (fun j=>(c.law j:ℝ)) (fun j=>imageLaw (g j)))+
tv (bind (fun j=>(c.law j:ℝ)) (fun j=>imageLaw (g j)))
(bind (fun j=>(c.law j:ℝ)) P) := tv_triangle _ _ _
_ ≤ 2*c.size/(2:ℝ)^k+e := add_le_add
((bind_contraction _ _ _ (fun _=>imageLaw_nonneg _) (fun _=>imageLaw_sum _)).trans (c.draw_tv k))
(bind_perturbation_on _ _ _ (fun j=>by exact_mod_cast c.law_nonneg j)
(c.real_law_sum) e (fun j hj=>he j (by exact_mod_cast hj)))
end MatchingFPRAS.WeightedOptions
namespace MatchingFPRAS.Replica
open Finset Variation
variable {I Ω B : Type*} [Fintype I] [DecidableEq I] [Fintype Ω] [DecidableEq Ω]
variable [Fintype B] [Nonempty B] [LinearOrder (Update I)]
def admissible (guides : I → Finset I) (base : Finset I) : Option (Update I) → Prop
| none => True
| some (.inl ij) => ij.2∈guides ij.1
| some (.inr i) => i∈base
lemma scanChoice_support (guides : I → Finset I) (base : Finset I) (hb : base.Nonempty)
(u : Option (Update I)) (hu : (scanChoice guides base hb).law u≠0) :
admissible guides base u := by
cases u with
| none => trivial
| some u =>
by_contra h
apply hu
simp only [scanChoice,WeightedOptions.mix_law,WeightedOptions.pure_law,
WeightedOptions.map_law]
simp only [reduceCtorEq,ite_false,Option.some.injEq,sum_ite_eq',mem_univ,ite_true]
rw [WeightedOptions.uniform_law]
have hn : u∉updates guides base := by
cases u <;> simpa [updates,admissible] using h
simp [hn]
omit [LinearOrder (Update I)] in
lemma localSampler_tv_on [LinearOrder (Update I)] (p : I → Ω → ℝ) (Q : ∀ x y,PairCapacity p x y)
(guides : I → Finset I) (base : Finset I)
(pair : I → I → (Ω×Ω) → B → Ω×Ω) (refresh : I → B → Ω) (e : ℝ) (he : 0≤e)
(hp : ∀ x y,y∈guides x → ∀ a,tv (imageLaw (pair x y a))
(fun b=>(Q x y).q a b/(p x a.1*p y a.2))≤e)
(hr : ∀ i,i∈base → tv (imageLaw (refresh i)) (p i)≤e)
(s : I → Ω) (u : Option (Update I)) (hu : admissible guides base u) :
tv (imageLaw (localSampler pair refresh s u)) (updateKernel p Q s u)≤e := by
cases u with
| none =>
have h : imageLaw (localSampler pair refresh s none)=updateKernel p Q s none := by
funext t
simp only [imageLaw,push,localSampler,updateKernel]
by_cases hst : s=t
· subst t
simpa using uniform_sum (A:=B)
· simp [hst]
rw [h,tv_self]
exact he
| some u => cases u with
| inl ij =>
have hk : updateKernel p Q s (some (.inl ij))=
push (fun b=>(Q ij.1 ij.2).q (s ij.1,s ij.2) b/(p ij.1 (s ij.1)*p ij.2 (s ij.2)))
(replacePair ij.1 ij.2 s) := by
funext t
simp only [updateKernel,pairStep,push]
rw [hk]
change tv (imageLaw ((replacePair ij.1 ij.2 s) ∘ pair ij.1 ij.2 (s ij.1,s ij.2)))
(push (fun b=>(Q ij.1 ij.2).q (s ij.1,s ij.2) b/(p ij.1 (s ij.1)*p ij.2 (s ij.2)))
(replacePair ij.1 ij.2 s))≤e
rw [imageLaw_comp]
exact (push_contraction _ _ _).trans (hp _ _ hu _)
| inr i =>
have hk : updateKernel p Q s (some (.inr i))=push (p i) (Function.update s i) := by
funext t
simp only [updateKernel,baseStep,push]
apply sum_congr rfl
intro a _
congr 1
rw [hk]
change tv (imageLaw ((Function.update s i) ∘ refresh i)) (push (p i) (Function.update s i))≤e
rw [imageLaw_comp]
exact (push_contraction _ _ _).trans (hr i hu)
theorem sampleScan_tv_on (p : I → Ω → ℝ) (hp : ∀ i a,0<p i a) (hs : ∀ i,∑ a,p i a=1)
(guides : I → Finset I) (hself : ∀ x y,y∈guides x → x≠y)
(base : Finset I) (hb : base.Nonempty) (Q : ∀ x y,PairCapacity p x y)
(pair : I → I → (Ω×Ω) → B → Ω×Ω) (refresh : I → B → Ω) (e : ℝ) (he : 0≤e)
(hpr : ∀ x y,y∈guides x → ∀ a,tv (imageLaw (pair x y a))
(fun b=>(Q x y).q a b/(p x a.1*p y a.2))≤e)
(hr : ∀ i,i∈base → tv (imageLaw (refresh i)) (p i)≤e) (k : ℕ) (s : I → Ω) :
tv (imageLaw (sampleScan guides base hb pair refresh k s))
(FiniteChain.kernel (density p) (scanFlow p guides base Q) s)≤
2*(1+updateCount guides base)/(2:ℝ)^k+e := by
have ht := WeightedOptions.drawThen_tv_on (scanChoice guides base hb) (localSampler pair refresh s)
k (updateKernel p Q s) e (fun u hu=>
localSampler_tv_on p Q guides base pair refresh e he hpr hr s u (scanChoice_support guides base hb u hu))
have hl : Variation.bind (fun u=>((scanChoice guides base hb).law u:ℝ)) (updateKernel p Q s)=
FiniteChain.kernel (density p) (scanFlow p guides base Q) s := by
funext t
rw [scanChoice_law,localScan_kernel p hp hs guides hself base Q]
rw [hl,scanChoice_size] at ht
simpa only [Nat.cast_add,Nat.cast_one,sampleScan] using ht
open Finset
variable {Ω : Type*} [Fintype Ω] [DecidableEq Ω]
lemma metropolis_normalize (P : SymmetricProposal Ω) (u : Ω → ℝ) (hu : ∀ a,0<u a)
(c : ℝ) (hc : 0<c) (a b : Ω) :
metropolis P (fun x=>u x/c) a b=metropolis P u a b := by
have huc : ∀ x,0<u x/c:=fun x=>div_pos (hu x) hc
have hf := WeightedOptions.row_eq_of_off _ _ (metropolis_row P _ huc a)
(metropolis_row P _ hu a) a (fun b hab=>?_)
· exact congrFun hf b
rw [metropolis_acceptance _ _ huc _ _ hab,metropolis_acceptance _ _ hu _ _ hab]
congr 2
field_simp
end MatchingFPRAS.Replica
namespace MatchingFPRAS.Transport.Sparse
open Finset Replica Variation
variable {V E : Type*} [Fintype V] [DecidableEq V] [Fintype E] [LinearOrder E]
variable (ends : E → Sym2 V)
attribute [local instance] finsetOrder pmOrder
def rationalWeight (w : E → ℚ) (A : PM (fun e v=>v∈ends e)) : ℚ := ∏ e∈A.val,w e
omit [DecidableEq V] [Fintype E] [LinearOrder E] in
lemma rationalWeight_pos [DecidableEq V] [Fintype E] [LinearOrder E]
(w : E → ℚ) (hw : ∀ e,0<w e) (A : PM (fun e v=>v∈ends e)) :
0<rationalWeight ends w A := prod_pos (fun e _=>hw e)
omit [DecidableEq V] [Fintype E] [LinearOrder E] in
lemma rationalWeight_cast [DecidableEq V] [Fintype E] [LinearOrder E]
(w : E → ℚ) (A : PM (fun e v=>v∈ends e)) :
(rationalWeight ends w A:ℝ)=matchingWeight (fun e=>(w e:ℝ)) A := by
simp [rationalWeight,matchingWeight]
def rationalPairWeight (w z : E → ℚ) (a : PM (fun e v=>v∈ends e) × PM (fun e v=>v∈ends e)) : ℚ :=
rationalWeight ends w a.1*rationalWeight ends z a.2
lemma rationalPairWeight_pos (w z : E → ℚ) (hw : ∀ e,0<w e) (hz : ∀ e,0<z e)
(a : PM (fun e v=>v∈ends e) × PM (fun e v=>v∈ends e)) : 0<rationalPairWeight ends w z a :=
mul_pos (rationalWeight_pos ends w hw a.1) (rationalWeight_pos ends z hz a.2)
def pairStepTable (hloop : ∀ e,¬(ends e).IsDiag)
(hpar : ∀ e,(univ.filter (fun f=>ends f=ends e)).card≤2)
(w z : E → ℚ) (hw : ∀ e,0<w e) (hz : ∀ e,0<z e)
(a : PM (fun e v=>v∈ends e) × PM (fun e v=>v∈ends e)) :=
(pairTable ends hloop hpar a).metropolisChoice (rationalPairWeight ends w z)
(rationalPairWeight_pos ends w z hw hz) a
theorem pairStepTable_law (hloop : ∀ e,¬(ends e).IsDiag)
(hpar : ∀ e,(univ.filter (fun f=>ends f=ends e)).card≤2)
(w z : E → ℚ) (hw : ∀ e,0<w e) (hz : ∀ e,0<z e)
(a b : PM (fun e v=>v∈ends e) × PM (fun e v=>v∈ends e)) :
((pairStepTable ends hloop hpar w z hw hz a).law b:ℝ)=
metropolis (pairProposal ends hloop hpar) (pairLaw ends (fun e=>(w e:ℝ)) (fun e=>(z e:ℝ))) a b := by
rw [pairStepTable,WeightedOptions.metropolisChoice_law (pairProposal ends hloop hpar)
(pairTable ends hloop hpar) (pairTable_law ends hloop hpar)]
have hw' : ∀ e,(0:ℝ)<w e:=fun e=>by exact_mod_cast hw e
have hz' : ∀ e,(0:ℝ)<z e:=fun e=>by exact_mod_cast hz e
let c:=partition (inc:=fun e v=>v∈ends e) (fun e=>(w e:ℝ))*
partition (inc:=fun e v=>v∈ends e) (fun e=>(z e:ℝ))
have hc : 0<c:=mul_pos (partition_pos _ hw' a.1) (partition_pos _ hz' a.2)
have he : pairLaw ends (fun e=>(w e:ℝ)) (fun e=>(z e:ℝ))=
(fun x=>(rationalPairWeight ends w z x:ℝ)/c) := by
funext x
simp only [pairLaw,gibbs,rationalPairWeight,Rat.cast_mul,rationalWeight_cast,c]
exact div_mul_div_comm _ _ _ _
rw [he,metropolis_normalize _ _ (fun x=>by exact_mod_cast rationalPairWeight_pos ends w z hw hz x) c hc]
theorem pairStepTable_tv (hloop : ∀ e,¬(ends e).IsDiag)
(hpar : ∀ e,(univ.filter (fun f=>ends f=ends e)).card≤2)
(w z : E → ℚ) (hw : ∀ e,0<w e) (hz : ∀ e,0<z e)
(a : PM (fun e v=>v∈ends e) × PM (fun e v=>v∈ends e)) (k : ℕ) :
tv (imageLaw ((pairStepTable ends hloop hpar w z hw hz a).draw k))
(metropolis (pairProposal ends hloop hpar) (pairLaw ends (fun e=>(w e:ℝ)) (fun e=>(z e:ℝ))) a) ≤
4*(8*a.1.val.card.choose 2+2*a.1.val.card+(a.1.val.card+a.2.val.card)+3)/(2:ℝ)^k := by
have ht := (pairStepTable ends hloop hpar w z hw hz a).draw_tv k
have hl : (fun b=>((pairStepTable ends hloop hpar w z hw hz a).law b:ℝ))=
metropolis (pairProposal ends hloop hpar) (pairLaw ends (fun e=>(w e:ℝ)) (fun e=>(z e:ℝ))) a :=
funext (pairStepTable_law ends hloop hpar w z hw hz a)
rw [hl] at ht
apply ht.trans
rw [pairStepTable,WeightedOptions.metropolisChoice_size]
apply div_le_div_of_nonneg_right _ (by positivity)
have hs := pairTable_size ends hloop hpar a
have hs' : ((pairTable ends hloop hpar a).size:ℝ)≤
8*a.1.val.card.choose 2+2*a.1.val.card+(a.1.val.card+a.2.val.card)+3 := by exact_mod_cast hs
push_cast
nlinarith
end MatchingFPRAS.Transport.Sparse
namespace MatchingFPRAS.FiniteChoice
lemma choose_pos {r K : ℕ} (p : Fin r → ℚ) (hs : ∑ i,p i=1)
(hK : 0<K) (J : Fin K) : 0<p (choose p hs hK J) := by
have hl := choose_lower p hs hK J
have hu := choose_upper p hs hK J
have hd := cumulative_step p (choose p hs hK J)
linarith
lemma chooseBits_pos {r : ℕ} (p : Fin r → ℚ) (hs : ∑ i,p i=1)
(k : ℕ) (bits : Fin k → Bool) : 0<p (chooseBits p hs k bits) :=
choose_pos p hs _ _
end MatchingFPRAS.FiniteChoice
namespace MatchingFPRAS.UnitRefresh
instance {α : Type*} [Finite α] : Finite (Pairing α) := by
apply Finite.of_injective Pairing.mate
intro p q h
cases p; cases q
simp only [Pairing.mk.injEq] at *
exact h
noncomputable instance {α : Type*} [Fintype α] : Fintype (Pairing α) := Fintype.ofFinite _
variable {α β : Type*}
variable [DecidableEq α]
universe u
open Finset Polynomial
def completionSum (a : ℕ) : ℕ[X] →+ ℕ where
toFun p := p.sum (fun k c => c * pairingCount (a+k))
map_zero' := Polynomial.sum_zero_index _
map_add' p q := Polynomial.sum_add_index p q _ (by simp) (by intros; exact Nat.add_mul ..)
@[simp] lemma completion_monomial (a k c : ℕ) :
completionSum a (monomial k c)=c*pairingCount (a+k) := by
change (monomial k c : ℕ[X]).sum (fun j d => d * pairingCount (a+j)) = _
exact Polynomial.sum_monomial_index c _ (Nat.zero_mul _)
noncomputable def interfacePolynomial (s : ℕ) (F : Fin (s+1) → ℕ) : ℕ[X] :=
∑ l : Fin (s+1), monomial (s-l.val) (s.choose l.val * F l)
variable {I : Type*} [Fintype I] [DecidableEq I]
noncomputable def convolution (s : I → ℕ) (F : ∀ i, Fin (s i+1) → ℕ) : ℕ[X] :=
∏ i, interfacePolynomial (s i) (F i)
omit [Fintype I] in
lemma prod_monomials (t : Finset I) (n c : I → ℕ) :
(∏ i ∈ t, monomial (n i) (c i) : ℕ[X]) = monomial (∑ i ∈ t,n i) (∏ i ∈ t,c i) := by
induction t using Finset.induction_on with
| empty => simp
| @insert i t hi ih => simp [hi,ih,Polynomial.monomial_mul_monomial]
theorem convolution_recurrence (s : I → ℕ) (F : ∀ i, Fin (s i+1) → ℕ) (u k : ℕ) :
completionSum (u+k) (convolution s F) =
∑ l : ∀ i, Fin (s i+1),
pairingCount (u+k+(∑ i, (s i - (l i).val))) * (∏ i, ((s i).choose (l i).val * F i (l i))) := by
classical
unfold convolution interfacePolynomial
rw [Fintype.prod_sum,map_sum]
apply Finset.sum_congr rfl
intro l hl
rw [prod_monomials,completion_monomial,Nat.mul_comm]
open Finset Polynomial
lemma interface_natDegree (s : ℕ) (F : Fin (s+1) → ℕ) :
(interfacePolynomial s F).natDegree ≤ s := by
apply Polynomial.natDegree_sum_le_of_forall_le
intro l hl
exact (Polynomial.natDegree_monomial_le _).trans (Nat.sub_le _ _)
variable {I : Type*} [Fintype I] [DecidableEq I]
omit [DecidableEq I] in
lemma convolution_natDegree (s : I → ℕ) (F : ∀ i, Fin (s i+1) → ℕ) :
(convolution s F).natDegree ≤ ∑ i,s i := by
apply (Polynomial.natDegree_prod_le _ _).trans
exact Finset.sum_le_sum fun i _ => interface_natDegree (s i) (F i)
omit [DecidableEq I] in
theorem convolution_finite_evaluation (s : I → ℕ) (F : ∀ i, Fin (s i+1) → ℕ)
(N u k : ℕ) (hN : (∑ i,s i) ≤ N) :
completionSum (u+k) (convolution s F) =
∑ a ∈ Finset.range (N+1), (convolution s F).coeff a * pairingCount (u+k+a) := by
change (convolution s F).sum (fun a c => c * pairingCount (u+k+a)) = _
apply Polynomial.sum_eq_of_subset
· simp
· intro a ha
apply Finset.mem_range.mpr
by_contra hn
have hz := Polynomial.coeff_eq_zero_of_natDegree_lt
(lt_of_le_of_lt (convolution_natDegree s F |>.trans hN) (by omega : N<a))
exact Polynomial.mem_support_iff.mp ha hz
def Pairing.sigma {L : Type*} {A : L → Type*} (p : ∀ l, Pairing (A l)) : Pairing (Sigma A) where
mate x := ⟨x.1,(p x.1).mate x.2⟩
involutive x := by
cases x with
| mk l x => exact congrArg (Sigma.mk l) ((p l).involutive x)
no_fixed x h := by
have he : (p x.1).mate x.2=x.2 := eq_of_heq (Sigma.mk.inj_iff.mp h).2
exact (p x.1).no_fixed x.2 he
variable {V L : Type*} [Fintype V] [Fintype L] [DecidableEq V] [DecidableEq L]
structure ColoredPairing (bags : V → Finset L) where
pair : Pairing V
color : V → L
allowed : ∀ x, color x ∈ bags x
same_color : ∀ x, color (pair.mate x)=color x
omit [Fintype V] [Fintype L] [DecidableEq V] [DecidableEq L] in
@[ext] lemma ColoredPairing.ext {bags : V → Finset L} {p q : ColoredPairing bags}
(hp : p.pair=q.pair) (hc : p.color=q.color) : p=q := by
cases p; cases q; simp_all
instance (bags : V → Finset L) : Finite (ColoredPairing bags) :=
Finite.of_injective (fun p : ColoredPairing bags => (p.pair,p.color)) (by
intro p q h
exact ColoredPairing.ext (congrArg Prod.fst h) (congrArg Prod.snd h))
noncomputable instance (bags : V → Finset L) : Fintype (ColoredPairing bags) := Fintype.ofFinite _
abbrev Assignment (bags : V → Finset L) := {f : V → L // ∀ x, f x ∈ bags x}
def ColoredPairing.fiber {bags : V → Finset L} (p : ColoredPairing bags) (l : L) :
Pairing {x : V // p.color x=l} where
mate x := ⟨p.pair.mate x,(p.same_color x).trans x.property⟩
involutive x := Subtype.ext (p.pair.involutive x)
no_fixed x h := p.pair.no_fixed x (congrArg Subtype.val h)
def ColoredPairing.glue (bags : V → Finset L) (f : Assignment bags)
(p : ∀ l,Pairing {x : V // f.val x=l}) : ColoredPairing bags where
pair := (Pairing.sigma p).map (Equiv.sigmaFiberEquiv f.val)
color := f.val
allowed := f.property
same_color x := (p (f.val x)).mate ⟨x,rfl⟩ |>.property
def assignmentPairingEquiv (bags : V → Finset L) :
ColoredPairing bags ≃ Σ f : Assignment bags, ∀ l, Pairing {x : V // f.val x=l} where
toFun p := ⟨⟨p.color,p.allowed⟩,p.fiber⟩
invFun q := ColoredPairing.glue bags q.1 q.2
left_inv p := by
apply ColoredPairing.ext
· ext x; rfl
· rfl
right_inv q := by
rcases q with ⟨f,p⟩
change (⟨f,(ColoredPairing.glue bags f p).fiber⟩ :
Σ f : Assignment bags, ∀ l, Pairing {x : V // f.val x=l}) = ⟨f,p⟩
apply congrArg (fun q : ∀ l, Pairing {x : V // f.val x=l} =>
(⟨f,q⟩ : Σ f : Assignment bags, ∀ l, Pairing {x : V // f.val x=l}))
funext l
ext x
change ((p (f.val x)).mate ⟨x,rfl⟩).val = ((p l).mate x).val
obtain ⟨x,hx⟩ := x
dsimp at hx ⊢
subst l
rfl
theorem coloredPairing_card (bags : V → Finset L) :
Fintype.card (ColoredPairing bags) =
∑ f : Assignment bags, ∏ l : L, pairingCount (Fintype.card {x : V // f.val x=l}) := by
classical
rw [Fintype.card_congr (assignmentPairingEquiv bags),Fintype.card_sigma]
apply Finset.sum_congr rfl
intro f hf
rw [Fintype.card_pi]
apply Finset.prod_congr rfl
intro l hl
exact pairing_card
end MatchingFPRAS.UnitRefresh
end OAI