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Sync from openai/math@faee2cf485a8 (part 7)
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import OAI.Analysis.FourierLLogL.Edges.Wire
/-! # Cost of an observed boundary window -/
open Function Set Filter
open scoped Topology BigOperators ComplexConjugate
noncomputable section
namespace OAI
namespace FourierLLogL.Dyadic.Procedure
open Law Node Real Period Compress.Params Thermal Fund Scene Fork Road Event Journal
namespace Wire
variable {M : ℕ} {s : Scene M} {t : Wire M s}
open scoped Classical
private lemma spotted_equal {s : Scene M} (h : ReadyAt s) (hm : 0 < s.mass)
(q : Grid M → Prop) (hq : spotted q s.here.lev) :
s.actor.prob q = (s.here.dice M).prob q := by
let c := s.here.start M
have hc : c∈s.here.block M := start_mem h.1.1 h.1.2
have hh (P : Law (Grid M)) (hp : ∀ x, 0 < P x → x∈s.here.block M) :
P.prob q = if q c then 1 else 0 := by
unfold prob
conv_rhs => rw [← Ex_const P (if q c then 1 else 0)]
refine Ex_congr_mem _ fun x hx => ?_
have H := hq _ rfl _ (hp x hx) _ hc
by_cases hv : q c <;> simp [hv,H]
exact (hh _ (piece_support h.1 (actor_def h.1 h.2 hm))).trans (hh _
(fun x hx => (dice_positive h.1).mp hx)).symm
def coverL (n : ℕ) (l : List (Pulse M)) : ℝ := ((l.take n).map Pulse.realized).sum
def fairValue (q : Grid M → Prop) (n : ℕ) (l : List (Pulse M)) (x : Grid M) :=
if q x then exp (-coverL n l) else 0
private lemma present {s : Scene M} (t : Wire M s) {a : Bool} (h : t.Valid a)
(hm : 0 < s.mass) (n : ℕ) (hn : s.here.lev+n ≤ M) (q : Grid M → Prop)
(hq : spotted q (s.here.lev+n)) :
s.actor.Ex (fun x => fairValue q n (t.read x) x) ≤ (s.here.dice M).prob q := by
classical
induction t generalizing n a with
| term s =>
obtain ⟨hh,he⟩ := h
have H : n = 0 := by omega
subst n
simp only [Nat.add_zero] at hq
rw [← spotted_equal hh hm _ hq]
unfold prob; simp only [fairValue,coverL,List.take_zero,List.map_nil,List.sum_nil,
neg_zero,exp_zero]; exact le_rfl
| stay s v k ih =>
cases v <;> exact ih h.2 hm n hn hq
| spot s u k ih =>
obtain ⟨ha,h2,hH,hk⟩ := h
have he := hH hm
rw [spotEx u k (fairValue q n) he]
rw [← Ex_const u.snip.probs ((s.here.dice M).prob q)]
apply Ex_mono_mem
intro b hb
have hx := ih b (hk b) ((true_mass he).mp hb) n
(by rw [h2 b]; exact hn) (by rw [h2 b]; exact hq)
rw [h2 b] at hx
exact hx
| link s g k ih =>
obtain ⟨ha,hG,hV,hk⟩ := h
have he : (step s).TrueLaw := step_true ha.1.1 hG ha.2 hm
cases n with
| zero =>
simp only [Nat.add_zero] at hq
rw [← spotted_equal ha hm _ hq]
unfold prob; simp only [fairValue,coverL,List.take_zero,List.map_nil,List.sum_nil,
neg_zero,exp_zero]; exact le_rfl
| succ n =>
rw [linkEx g k (fairValue q (n+1)) he]
let P := (step s).probs
let V (b) := (s.smaller b).actor
let Z (b) := fun x => fairValue q (n+1) (⟨s,g,b⟩::(k b).read x) x
have HE (b : Bool) :
P b * (V b).Ex (Z b) ≤ (1/2)*(s.smaller b |>.here.dice M).prob q := by
rcases eq_or_lt_of_le (P.nonneg b) with hi|hi
· rw [← hi,zero_mul]
apply mul_nonneg (by norm_num) (prob_nonneg _ _)
have hP : (s.smaller b).here.lev+n=s.here.lev+(n+1) := by cases b <;>
simp [smaller,child,L,R,add_comm n,add_assoc]
have H := ih b (hk b) ((true_mass he).mp hi) n (by rw [hP]; exact hn)
(by rw [hP]; exact hq)
have hZ (x : Grid M) : Z b x =
(2*P b)⁻¹ * fairValue q n ((k b).read x) x := by
unfold Z fairValue; split_ifs
· unfold coverL; simp only [List.take_succ_cons,List.map_cons,List.sum_cons, Pulse.realized]
rw [show -(whistle _ _+_)= -whistle (step s) b + -coverL n ((k b).read x) by
unfold coverL; ring,exp_add,Real.exp_neg,whistle,exp_log (by change 0< 2* P b; positivity)]
rfl
· ring
rw [funext hZ,Ex_lmul, ← mul_assoc]
rw [show P b*(2*P b)⁻¹=1/2 by field_simp]
exact mul_le_mul_of_nonneg_left H (by norm_num)
change P.Ex (fun b => (V b).Ex (Z b)) ≤ _
rw [Ex,Fintype.sum_bool]
apply (add_le_add (HE true) (HE false)).trans
unfold prob
rw [dice_child s.here ha.1.1 hG]
simp only [smaller,child]
linarith
def startMark (i : ℕ) (l : List (Pulse M)) : Prop :=
reach i * log 2/2 ≤ coverL (reach i) l
private lemma distance_scale (i : ℕ) (main : Bool) :
exp ((reach i)*log 2/2)*(4*side (reach i)) ≤ gateWidth main i/4 := by
let n := 40+4*i
have hi : reach i = 2*n := by unfold reach n; omega
have hE :
exp (((reach i):ℝ)*log 2/2)*(4*side (reach i)) = 4 * side n := by
rw [hi,Nat.cast_mul,Nat.cast_ofNat,show 2*(n:ℝ)*log 2/2=log (2^n) by rw [log_pow]; ring,
exp_log (by positivity : 0 < (2:ℝ)^n)]
unfold side
rw [mul_comm 2 n,pow_mul,one_div,inv_pow]
field_simp
rw [hE]
have he : side n = side 40 * side i ^ 4 := by
unfold n side; rw [pow_add,mul_comm 4 i,pow_mul]
unfold gateWidth; rw [he]
have hQ : side i^4 ≤ side i^2 :=
pow_le_pow_of_le_one (side_pos _).le (side_le _) (by omega)
have h₂ : side i^2 ≤ side i := by
simpa using pow_le_pow_of_le_one (side_pos i).le (side_le i) (by omega : 1 ≤ 2)
split <;> norm_num [side] at * <;> nlinarith
theorem mark_chance {s : Scene M} (t : Wire M s) {a : Bool} (h : t.Valid a)
(hm : 0 < s.mass) (ht : ¬ enter s) (main : Bool) (i : ℕ) (hh : hazard s main i) :
let P := s.actor
P.prob (flanked s.here i) ≤ 2*P.prob (fun x => startMark i (t.read x)) := by
obtain ⟨hx1,hx2⟩ := h.atSrc
obtain ⟨hi,hj,hc⟩ := hazard_rule hx1 hx2 hm ht hh
let q := flanked (M:=M) s.here i
let n := reach i; let r := n * log 2/2
intro P
have HH := present t h hm n hi q (flanked_at _ _)
have H₁ := HH.trans (flank_prob _ hx1.1 i hi)
let f := fun x => fairValue q n (t.read x) x
let b := fun x => startMark i (t.read x)
let F (x) := if b x then (1:ℝ) else 0
have H :
P.prob q ≤ P.prob b + exp r*P.Ex f := by
unfold prob
rw [← Ex_lmul, ← Ex_add]
refine Ex_mono _ fun x => ?_
unfold f fairValue
by_cases h1 : q x
· simp only [h1,ite_true]
split_ifs with H
· have H : 0 ≤ exp r * exp (-coverL n (t.read x)) := by positivity
linarith
rw [zero_add,← exp_add]; apply Real.one_le_exp
change ¬ r ≤ coverL n (t.read x) at H; linarith
simp only [h1,ite_false]; split_ifs <;> norm_num
have hT : exp r * P.Ex f ≤ gateWidth main i /4 :=
(mul_le_mul_of_nonneg_left H₁ (exp_nonneg _)).trans (distance_scale i main)
change gateWidth main i/2 ≤ P.prob q at hc
change P.prob q ≤ 2*P.prob b
linarith
end Wire
end FourierLLogL.Dyadic.Procedure
end OAI