Download lean/OAI/Computability/UniqueGames/Decoding/MaskMomentLemmas.lean from roseking/openAI-math-dataset: direct link, hf CLI and curl.
- Browser
- Download file 18.3 kB
-
https://huggingface.co/datasets/roseking/openAI-math-dataset/resolve/main/lean/OAI/Computability/UniqueGames/Decoding/MaskMomentLemmas.lean
- Command line
-
hf download hf://datasets/roseking/openAI-math-dataset/lean/OAI/Computability/UniqueGames/Decoding/MaskMomentLemmas.lean
-
curl -L -o MaskMomentLemmas.lean https://huggingface.co/datasets/roseking/openAI-math-dataset/resolve/main/lean/OAI/Computability/UniqueGames/Decoding/MaskMomentLemmas.lean
18.3 kB
| import Mathlib.Analysis.Complex.Exponential | |
| import Mathlib.Analysis.SpecificLimits.Basic | |
| import Mathlib.Tactic.FieldSimp | |
| import Mathlib.Tactic.Linarith | |
| import Mathlib.Tactic.Ring | |
| import OAI.Computability.UniqueGames.Foundations.SamplingLemmas | |
| import OAI.Computability.UniqueGames.Games.FinishBoundsLemmas | |
| namespace OAI | |
| section | |
| namespace UniqueGamesTheorem.Clean | |
| open Foundations.Games | |
| open scoped BigOperators | |
| noncomputable section | |
| /-- `true` is the singleton branch. -/ | |
| def bernoulli (p : ℝ) (hp₀ : 0 ≤ p) (hp₁ : p ≤ 1) : | |
| FiniteDistribution Bool where | |
| weight b := if b then p else 1 - p | |
| nonnegative b := by cases b <;> simp [hp₀, sub_nonneg.mpr hp₁] | |
| normalized := by simp | |
| /-- The exact mask, including the empty mask at `k = 0`. -/ | |
| def maskCount {k : ℕ} (mask : Fin k → Bool) : ℕ := | |
| (Finset.univ.filter fun i => mask i = true).card | |
| theorem product_mask {k : ℕ} (mask : Fin k → Bool) (ρ : ℝ) : | |
| (∏ i, if mask i then ρ else 1) = ρ ^ maskCount mask := by | |
| classical | |
| simp [maskCount, Finset.prod_ite] | |
| /-- The finite product identity underlying the binomial generating function. -/ | |
| theorem iid_product_moment {Ω : Type*} [Fintype Ω] | |
| (μ : FiniteDistribution Ω) (f : Ω → ℝ) (k : ℕ) : | |
| (μ.iid k).expectation (fun x => ∏ i, f (x i)) = μ.expectation f ^ k := by | |
| classical | |
| unfold FiniteDistribution.expectation FiniteDistribution.iid | |
| rw [Fintype.sum_pow] | |
| apply Finset.sum_congr rfl | |
| intro x _ | |
| rw [Finset.prod_mul_distrib] | |
| theorem bernoulli_mask_moment (p : ℝ) (hp₀ : 0 ≤ p) (hp₁ : p ≤ 1) | |
| (k : ℕ) (ρ : ℝ) : | |
| ((bernoulli p hp₀ hp₁).iid k).expectation (fun mask => ρ ^ maskCount mask) = | |
| (1 - p * (1 - ρ)) ^ k := by | |
| calc | |
| _ = ((bernoulli p hp₀ hp₁).iid k).expectation | |
| (fun mask => ∏ i, if mask i then ρ else 1) := | |
| FiniteDistribution.expectation_congr _ (fun mask => (product_mask mask ρ).symm) | |
| _ = ((bernoulli p hp₀ hp₁).expectation (fun b => if b then ρ else 1)) ^ k := | |
| iid_product_moment (bernoulli p hp₀ hp₁) (fun b : Bool => if b then ρ else 1) k | |
| _ = _ := by | |
| congr 1 | |
| simp [FiniteDistribution.expectation, bernoulli] | |
| ring | |
| variable {E : Type*} [Fintype E] [Nonempty E] | |
| def cleanProbability (β : ℝ) (E : Type*) [Fintype E] : ℝ := | |
| β / (Fintype.card E : ℝ) | |
| omit [Nonempty E] in | |
| theorem cleanProbability_nonneg {β : ℝ} (hβ₀ : 0 ≤ β) : | |
| 0 ≤ cleanProbability β E := | |
| div_nonneg hβ₀ (Nat.cast_nonneg _) | |
| theorem cleanProbability_le_one {β : ℝ} (hβ₁ : β ≤ 1) : | |
| cleanProbability β E ≤ 1 := by | |
| have hc : (1 : ℝ) ≤ Fintype.card E := by | |
| exact_mod_cast Fintype.card_pos (α := E) | |
| apply (div_le_iff₀ (lt_of_lt_of_le zero_lt_one hc)).mpr | |
| simpa using hβ₁.trans hc | |
| /-- Independent singleton choice and uniform advice slope. -/ | |
| def singletonSlopeLaw (β : ℝ) (hβ₀ : 0 ≤ β) (hβ₁ : β ≤ 1) : | |
| FiniteDistribution (Bool × E) := | |
| (bernoulli β hβ₀ hβ₁).product (FiniteDistribution.uniform E) | |
| /-- `origin` is instantiated by the zero advice slope. Keeping it explicit also | |
| shows that every specified slope has exactly the same chance. -/ | |
| def cleanBit (origin : E) (sample : Bool × E) : Bool := by | |
| classical | |
| exact sample.1 && decide (sample.2 = origin) | |
| theorem clean_pushforward (β : ℝ) (hβ₀ : 0 ≤ β) (hβ₁ : β ≤ 1) (origin : E) : | |
| (singletonSlopeLaw (E := E) β hβ₀ hβ₁).pushforward (cleanBit origin) = | |
| bernoulli (cleanProbability β E) | |
| (cleanProbability_nonneg hβ₀) (cleanProbability_le_one hβ₁) := by | |
| classical | |
| let μ := (singletonSlopeLaw (E := E) β hβ₀ hβ₁).pushforward (cleanBit origin) | |
| have ht : μ.weight true = cleanProbability β E := by | |
| simp [μ, FiniteDistribution.pushforward, singletonSlopeLaw, | |
| FiniteDistribution.product, Fintype.sum_prod_type, | |
| bernoulli, cleanBit, FiniteDistribution.uniform, cleanProbability, div_eq_mul_inv] | |
| apply FiniteDistribution.eq_of_weight_eq | |
| intro b | |
| cases b with | |
| | false => | |
| change μ.weight false = 1 - cleanProbability β E | |
| have hn := μ.normalized | |
| simp only [Fintype.sum_bool] at hn | |
| linarith | |
| | true => exact ht | |
| /-- In particular, the *whole* mask has the independent Bernoulli law. -/ | |
| theorem clean_mask_law (β : ℝ) (hβ₀ : 0 ≤ β) (hβ₁ : β ≤ 1) | |
| (origin : E) (k : ℕ) : | |
| ((singletonSlopeLaw (E := E) β hβ₀ hβ₁).iid k).pushforward | |
| (fun sample i => cleanBit origin (sample i)) = | |
| (bernoulli (cleanProbability β E) | |
| (cleanProbability_nonneg hβ₀) (cleanProbability_le_one hβ₁)).iid k := by | |
| rw [← FiniteDistribution.iid_pushforward, clean_pushforward] | |
| theorem clean_mask_moment (β : ℝ) (hβ₀ : 0 ≤ β) (hβ₁ : β ≤ 1) | |
| (origin : E) (k : ℕ) (ρ : ℝ) : | |
| ((singletonSlopeLaw (E := E) β hβ₀ hβ₁).iid k).expectation | |
| (fun sample => ρ ^ maskCount (fun i => cleanBit origin (sample i))) = | |
| (1 - cleanProbability β E * (1 - ρ)) ^ k := by | |
| rw [← FiniteDistribution.expectation_pushforward | |
| ((singletonSlopeLaw (E := E) β hβ₀ hβ₁).iid k) | |
| (fun sample i => cleanBit origin (sample i)) (fun mask => ρ ^ maskCount mask)] | |
| rw [clean_mask_law, bernoulli_mask_moment] | |
| theorem cleanProbability_ge_of_card_le {β : ℝ} (hβ₀ : 0 ≤ β) {N : ℝ} | |
| (hcard : (Fintype.card E : ℝ) ≤ N) : | |
| β / N ≤ cleanProbability β E := by | |
| exact div_le_div_of_nonneg_left hβ₀ | |
| (Nat.cast_pos.mpr Fintype.card_pos) hcard | |
| theorem cleanProbability_ge_dimension {β : ℝ} (hβ₀ : 0 ≤ β) (dimW rs : ℕ) | |
| (hcard : Fintype.card E ≤ 2 ^ (dimW + rs)) : | |
| β * (2 : ℝ) ^ (-((dimW + rs : ℕ) : ℤ)) ≤ cleanProbability β E := by | |
| rw [zpow_neg, zpow_natCast, ← div_eq_mul_inv] | |
| apply cleanProbability_ge_of_card_le hβ₀ | |
| exact_mod_cast hcard | |
| /-- Larger clean probability decreases the moment for a rate in `[0,1]`. -/ | |
| theorem mask_rate_antitone {p q ρ : ℝ} (hp₀ : 0 ≤ p) (hp₁ : p ≤ 1) | |
| (hqp : q ≤ p) (hρ₀ : 0 ≤ ρ) (hρ₁ : ρ ≤ 1) (k : ℕ) : | |
| (1 - p * (1 - ρ)) ^ k ≤ (1 - q * (1 - ρ)) ^ k := by | |
| have hl : 0 ≤ 1 - p * (1 - ρ) := by | |
| nlinarith [mul_nonneg hp₀ hρ₀] | |
| apply pow_le_pow_left₀ hl | |
| exact sub_le_sub_left (mul_le_mul_of_nonneg_right hqp (sub_nonneg.mpr hρ₁)) 1 | |
| /-- Section 5's numerical specialization. A bound on the number of possible | |
| advice slopes gives a uniform bound over every fixed advice map. -/ | |
| theorem clean_mask_moment_le (β : ℝ) (hβ₀ : 0 ≤ β) (hβ₁ : β ≤ 1) | |
| (origin : E) (k : ℕ) {N : ℝ} (hcard : (Fintype.card E : ℝ) ≤ N) : | |
| ((singletonSlopeLaw (E := E) β hβ₀ hβ₁).iid k).expectation | |
| (fun sample => (1 - (1 : ℝ) / 3600) ^ | |
| maskCount (fun i => cleanBit origin (sample i))) ≤ | |
| (1 - (β / N) / 3600) ^ k := by | |
| rw [clean_mask_moment] | |
| have h := mask_rate_antitone (cleanProbability_nonneg (E := E) hβ₀) | |
| (cleanProbability_le_one (E := E) hβ₁) | |
| (cleanProbability_ge_of_card_le hβ₀ hcard) | |
| (ρ := 1 - (1 : ℝ) / 3600) (by norm_num) (by norm_num) k | |
| convert h using 1 | |
| congr 1 | |
| ring | |
| /-- `2^(dim W + r_s)` is chosen before the particular advice-map rank. -/ | |
| theorem clean_mask_moment_le_dimension (β : ℝ) (hβ₀ : 0 ≤ β) (hβ₁ : β ≤ 1) | |
| (origin : E) (k dimW rs : ℕ) (hcard : Fintype.card E ≤ 2 ^ (dimW + rs)) : | |
| ((singletonSlopeLaw (E := E) β hβ₀ hβ₁).iid k).expectation | |
| (fun sample => (1 - (1 : ℝ) / 3600) ^ | |
| maskCount (fun i => cleanBit origin (sample i))) ≤ | |
| (1 - (β / (2 : ℝ) ^ (dimW + rs)) / 3600) ^ k := by | |
| apply clean_mask_moment_le β hβ₀ hβ₁ origin k | |
| exact_mod_cast hcard | |
| /-- The exponential estimate uses nonnegativity of `1 - x` before raising to | |
| a natural power. It also covers the empty mask. -/ | |
| theorem mask_rate_le_exp {x : ℝ} (hx : x ≤ 1) (k : ℕ) : | |
| (1 - x) ^ k ≤ Real.exp (-(k : ℝ) * x) := by | |
| calc | |
| (1 - x) ^ k ≤ Real.exp (-x) ^ k := | |
| pow_le_pow_left₀ (sub_nonneg.mpr hx) (Real.one_sub_le_exp_neg x) k | |
| _ = Real.exp (-(k : ℝ) * x) := by | |
| rw [← Real.exp_nat_mul] | |
| congr 1 | |
| ring | |
| theorem clean_mask_moment_le_exp (β : ℝ) (hβ₀ : 0 ≤ β) (hβ₁ : β ≤ 1) | |
| (origin : E) (k : ℕ) {N : ℝ} (hcard : (Fintype.card E : ℝ) ≤ N) : | |
| ((singletonSlopeLaw (E := E) β hβ₀ hβ₁).iid k).expectation | |
| (fun sample => (1 - (1 : ℝ) / 3600) ^ | |
| maskCount (fun i => cleanBit origin (sample i))) ≤ | |
| Real.exp (-(k : ℝ) * (β / N) / 3600) := by | |
| have hN : 1 ≤ N := by | |
| have hc : (1 : ℝ) ≤ Fintype.card E := by | |
| exact_mod_cast Fintype.card_pos (α := E) | |
| exact hc.trans hcard | |
| have hq : β / N ≤ 1 := (div_le_iff₀ (by linarith)).mpr (by simpa using hβ₁.trans hN) | |
| have hx : β / N / 3600 ≤ 1 := (div_le_iff₀ (by norm_num)).mpr (by linarith) | |
| have h := (clean_mask_moment_le β hβ₀ hβ₁ origin k hcard).trans | |
| (mask_rate_le_exp hx k) | |
| simpa only [mul_div_assoc] using h | |
| theorem cube_singleton_probability_nonneg (n : ℕ) : 0 ≤ (1 / (n : ℝ)) ^ 2 := | |
| sq_nonneg _ | |
| theorem cube_singleton_probability_le_one {n : ℕ} (hn : 1 ≤ n) : | |
| (1 / (n : ℝ)) ^ 2 ≤ 1 := by | |
| have hn' : (1 : ℝ) ≤ n := by exact_mod_cast hn | |
| have hq₀ : 0 ≤ 1 / (n : ℝ) := div_nonneg zero_le_one (Nat.cast_nonneg _) | |
| have hq₁ : 1 / (n : ℝ) ≤ 1 := | |
| (div_le_iff₀ (by linarith)).mpr (by simpa using hn') | |
| nlinarith [mul_nonneg hq₀ (sub_nonneg.mpr hq₁)] | |
| /-- On cubes, `k = n^3` and `beta = n^(-2)`, so `k * beta = n`. | |
| The advice-space size bound `N` is fixed independently of `n`. -/ | |
| theorem cube_mask_rate_le_exp {n : ℕ} (hn : 1 ≤ n) {N : ℝ} (hN : 1 ≤ N) : | |
| (1 - ((1 / (n : ℝ)) ^ 2 / N) / 3600) ^ (n ^ 3) ≤ | |
| Real.exp (-(n : ℝ) / (3600 * N)) := by | |
| have hn₀ : (n : ℝ) ≠ 0 := by | |
| have hn' : (1 : ℝ) ≤ n := by exact_mod_cast hn | |
| linarith | |
| have hN₀ : N ≠ 0 := by linarith | |
| have hq : (1 / (n : ℝ)) ^ 2 / N ≤ 1 := | |
| (div_le_iff₀ (by linarith)).mpr | |
| (by simpa using (cube_singleton_probability_le_one hn).trans hN) | |
| have hx : (1 / (n : ℝ)) ^ 2 / N / 3600 ≤ 1 := | |
| (div_le_iff₀ (by norm_num)).mpr (by linarith) | |
| have he : -((n ^ 3 : ℕ) : ℝ) * ((1 / (n : ℝ)) ^ 2 / N / 3600) = | |
| -(n : ℝ) / (3600 * N) := by | |
| simp only [Nat.cast_pow] | |
| field_simp [hn₀, hN₀] | |
| calc | |
| _ ≤ Real.exp (-((n ^ 3 : ℕ) : ℝ) * ((1 / (n : ℝ)) ^ 2 / N / 3600)) := | |
| mask_rate_le_exp hx (n ^ 3) | |
| _ = _ := congrArg Real.exp he | |
| /-- A repetition cube can be selected after fixing only the advice-space size | |
| bound and the required error. This is a scalar fact, not a game-value theorem. -/ | |
| theorem exists_cube_exponential_lt {N error : ℝ} (hN : 0 < N) (herror : 0 < error) : | |
| ∃ n : ℕ, 1 ≤ n ∧ Real.exp (-(n : ℝ) / (3600 * N)) < error := by | |
| let rate := Real.exp (-(1 / (3600 * N))) | |
| have hrate₀ : 0 ≤ rate := (Real.exp_pos _).le | |
| have hrate₁ : rate < 1 := Real.exp_lt_one_iff.mpr | |
| (neg_lt_zero.mpr (one_div_pos.mpr (mul_pos (by norm_num) hN))) | |
| have ht := tendsto_pow_atTop_nhds_zero_of_lt_one hrate₀ hrate₁ | |
| obtain ⟨m, hm⟩ := (ht.eventually (gt_mem_nhds herror)).exists | |
| refine ⟨m + 1, Nat.succ_le_succ (Nat.zero_le m), ?_⟩ | |
| have hp : rate ^ (m + 1) < error := | |
| lt_of_le_of_lt (by | |
| rw [pow_succ] | |
| exact mul_le_of_le_one_right (pow_nonneg hrate₀ m) hrate₁.le) hm | |
| have he : Real.exp (-((m + 1 : ℕ) : ℝ) / (3600 * N)) = rate ^ (m + 1) := by | |
| rw [← Real.exp_nat_mul] | |
| congr 1 | |
| ring | |
| rwa [he] | |
| theorem exists_cube_mask_rate_lt {N error : ℝ} (hN : 1 ≤ N) (herror : 0 < error) : | |
| ∃ n : ℕ, 1 ≤ n ∧ | |
| (1 - ((1 / (n : ℝ)) ^ 2 / N) / 3600) ^ (n ^ 3) < error := by | |
| obtain ⟨n, hn, he⟩ := exists_cube_exponential_lt (by linarith : 0 < N) herror | |
| exact ⟨n, hn, (cube_mask_rate_le_exp hn hN).trans_lt he⟩ | |
| end | |
| end UniqueGamesTheorem.Clean | |
| end | |
| section | |
| /-! | |
| Assembling private decoders from an actual finite advice experiment. | |
| The left response law accepts only the left observation and the right law only | |
| the right observation. Their samples are independent conditional on those | |
| observations. A positive conditional agreement bound on a positive-mass event | |
| therefore gives ordinary deterministic local strategies, by finite averaging. | |
| No hidden matrix, witness, or opposite-player observation is an argument of | |
| either response law. | |
| -/ | |
| namespace UniqueGamesTheorem.Decoder.StrategyAssembly | |
| open UniqueGamesTheorem.Foundations.Games | |
| open scoped BigOperators | |
| noncomputable section | |
| variable {Ω Q₁ Q₂ A₁ A₂ : Type*} | |
| variable [Fintype Ω] [Fintype Q₁] [Fintype Q₂] [Fintype A₁] [Fintype A₂] | |
| def observedGame (law : FiniteDistribution Ω) (leftObservation : Ω → Q₁) | |
| (rightObservation : Ω → Q₂) (accepts : Q₁ → Q₂ → A₁ → A₂ → Bool) : | |
| Game Q₁ Q₂ A₁ A₂ where | |
| questions := law.pushforward (fun ω => (leftObservation ω, rightObservation ω)) | |
| accepts := accepts | |
| def conditionalAgreement (left : Q₁ → FiniteDistribution A₁) | |
| (right : Q₂ → FiniteDistribution A₂) | |
| (accepts : Q₁ → Q₂ → A₁ → A₂ → Bool) (q₁ : Q₁) (q₂ : Q₂) : ℝ := | |
| ((left q₁).product (right q₂)).probability (fun a => accepts q₁ q₂ a.1 a.2) | |
| omit [Fintype Q₁] [Fintype Q₂] in | |
| theorem conditionalAgreement_nonnegative (left : Q₁ → FiniteDistribution A₁) | |
| (right : Q₂ → FiniteDistribution A₂) | |
| (accepts : Q₁ → Q₂ → A₁ → A₂ → Bool) (q₁ : Q₁) (q₂ : Q₂) : | |
| 0 ≤ conditionalAgreement left right accepts q₁ q₂ := | |
| FiniteDistribution.probability_nonnegative _ _ | |
| omit [Fintype Q₁] [Fintype Q₂] in | |
| theorem conditionalAgreement_le_one (left : Q₁ → FiniteDistribution A₁) | |
| (right : Q₂ → FiniteDistribution A₂) | |
| (accepts : Q₁ → Q₂ → A₁ → A₂ → Bool) (q₁ : Q₁) (q₂ : Q₂) : | |
| conditionalAgreement left right accepts q₁ q₂ ≤ 1 := | |
| FiniteDistribution.probability_le_one _ _ | |
| theorem stochasticSuccess_eq_actual_expectation | |
| [DecidableEq Q₁] [DecidableEq Q₂] | |
| (law : FiniteDistribution Ω) (leftObservation : Ω → Q₁) | |
| (rightObservation : Ω → Q₂) (accepts : Q₁ → Q₂ → A₁ → A₂ → Bool) | |
| (left : Q₁ → FiniteDistribution A₁) (right : Q₂ → FiniteDistribution A₂) : | |
| (observedGame law leftObservation rightObservation accepts).stochasticSuccess left right = | |
| law.expectation (fun ω => conditionalAgreement left right accepts | |
| (leftObservation ω) (rightObservation ω)) := by | |
| unfold Game.stochasticSuccess observedGame | |
| rw [FiniteDistribution.expectation_pushforward] | |
| apply FiniteDistribution.expectation_congr | |
| intro ω | |
| simp only [conditionalAgreement, FiniteDistribution.probability, | |
| FiniteDistribution.product, FiniteDistribution.expectation, Fintype.sum_prod_type] | |
| apply Finset.sum_congr rfl | |
| intro a _ | |
| rw [Finset.mul_sum] | |
| apply Finset.sum_congr rfl | |
| intro b _ | |
| by_cases h : accepts (leftObservation ω) (rightObservation ω) a b = true <;> simp [h] | |
| /-- Averaging conditional independent decoder success over the actual advice | |
| draw multiplies the two positive lower bounds. -/ | |
| theorem good_data_mass_lower | |
| [DecidableEq Q₁] [DecidableEq Q₂] | |
| (law : FiniteDistribution Ω) (leftObservation : Ω → Q₁) | |
| (rightObservation : Ω → Q₂) (accepts : Q₁ → Q₂ → A₁ → A₂ → Bool) | |
| (left : Q₁ → FiniteDistribution A₁) (right : Q₂ → FiniteDistribution A₂) | |
| (good : Ω → Bool) (γ₁ γ₂ : ℝ) (hγ₂ : 0 ≤ γ₂) | |
| (hmass : γ₁ ≤ law.probability good) | |
| (hagreement : ∀ ω, good ω = true → γ₂ ≤ | |
| conditionalAgreement left right accepts (leftObservation ω) (rightObservation ω)) : | |
| γ₁ * γ₂ ≤ | |
| (observedGame law leftObservation rightObservation accepts).stochasticSuccess left right := by | |
| rw [stochasticSuccess_eq_actual_expectation] | |
| have hweighted : law.probability good * γ₂ ≤ law.expectation | |
| (fun ω => conditionalAgreement left right accepts | |
| (leftObservation ω) (rightObservation ω)) := by | |
| unfold FiniteDistribution.probability FiniteDistribution.expectation | |
| rw [Finset.sum_mul] | |
| apply Finset.sum_le_sum | |
| intro ω _ | |
| by_cases hgood : good ω = true | |
| · simp only [hgood, ↓reduceIte] | |
| exact mul_le_mul_of_nonneg_left (hagreement ω hgood) (law.nonnegative ω) | |
| · simp only [hgood, Bool.false_eq_true, ↓reduceIte, zero_mul] | |
| exact mul_nonneg (law.nonnegative ω) (conditionalAgreement_nonnegative _ _ _ _ _) | |
| exact (mul_le_mul_of_nonneg_right hmass hγ₂).trans hweighted | |
| /-- The final strategies receive precisely their local observations. Private | |
| sampling is eliminated by the existing finite response-table construction. -/ | |
| theorem exists_local_deterministic_strategies | |
| [DecidableEq Q₁] [DecidableEq Q₂] [Nonempty A₁] [Nonempty A₂] | |
| (law : FiniteDistribution Ω) (leftObservation : Ω → Q₁) | |
| (rightObservation : Ω → Q₂) (accepts : Q₁ → Q₂ → A₁ → A₂ → Bool) | |
| (left : Q₁ → FiniteDistribution A₁) (right : Q₂ → FiniteDistribution A₂) | |
| (good : Ω → Bool) (γ₁ γ₂ : ℝ) (hγ₂ : 0 ≤ γ₂) | |
| (hmass : γ₁ ≤ law.probability good) | |
| (hagreement : ∀ ω, good ω = true → γ₂ ≤ | |
| conditionalAgreement left right accepts (leftObservation ω) (rightObservation ω)) : | |
| ∃ leftStrategy : Q₁ → A₁, ∃ rightStrategy : Q₂ → A₂, | |
| γ₁ * γ₂ ≤ law.probability (fun ω => accepts | |
| (leftObservation ω) (rightObservation ω) | |
| (leftStrategy (leftObservation ω)) (rightStrategy (rightObservation ω))) := by | |
| let G := observedGame law leftObservation rightObservation accepts | |
| obtain ⟨strategy, hstrategy⟩ := G.exists_deterministic_ge_stochastic left right | |
| refine ⟨strategy.1, strategy.2, ?_⟩ | |
| have h := (good_data_mass_lower law leftObservation rightObservation accepts | |
| left right good γ₁ γ₂ hγ₂ hmass hagreement).trans hstrategy | |
| simpa only [G, Game.success, observedGame, FiniteDistribution.probability_pushforward, | |
| Game.wins] using h | |
| end | |
| end UniqueGamesTheorem.Decoder.StrategyAssembly | |
| end | |
| end OAI | |