OAI/Probability/MatroidSecretary/Selection/AveragedSafeExact.lean
2 declarations, 0 contain sorry, 0 declared as axioms
The exact density-averaged safety loss
This retains the first, sharper inequality in eq:averaged-safe-count
(sections/transfer.tex, line 330). The density mask is averaged only after
the exact conditional loss has been bounded by |D ∩ U_i| / κ. The previous
endpoint route weakened this to |U_i| / κ before averaging, which suffices
there but does not state the displayed |U_i| / (4κ) estimate.
The statistic remains zero on unlisted outcomes. No conditioning on listing, focal density bits, or an arrival order is introduced.
- theorem
OAI.MatroidProphet.MainAlgorithm.listedSafeStatistic_averaged_exactline 26Source documentation
Literal first inequality of
eq:averaged-safe-count, for a fixed true group and any independent comparison subset of that group.theorem listedSafeStatistic_averaged_exact (M : Matroid (Fin n)) (hE : M.E = Set.univ) (κ : ℕ) (hκ : 0 < κ) (d : MainMasks n) (s : Fin n → Option ℤ) (i : ℤ) (Y : Set (Fin n)) (hY : Y ⊆ (trueGroup M d s i : Set (Fin n))) (hI : M.Indep Y) (q : Fin n → ℝ) (hq0 : ∀ e, 0 ≤ q e) (hq1 : ∀ e, q e ≤ 1) : retainedFraction * Y.ncard - (trueGroup M d s i).card / (4 * (κ : ℝ)) ≤ tripleMaskExpectation (fun _ => (1 : ℝ) / 4) q q univ (fun D C T => fairParityExpectation (fun p => (listedSafeStatistic M hE κ (withMasks d D C T) s i Y (boolParity p) : ℝ))) := by …Mentions: OAI.MatroidProphet.MainMasks, OAI.MatroidProphet.MainAlgorithm.trueGroup, OAI.MatroidProphet.retainedFraction, OAI.MatroidProphet.tripleMaskExpectation, OAI.MatroidProphet.fairParityExpectation, OAI.MatroidProphet.MainAlgorithm.listedSafeStatistic, OAI.MatroidProphet.MainAlgorithm.withMasks, OAI.MatroidProphet.boolParity
- theorem
OAI.MatroidProphet.MainAlgorithm.averaged_safe_sampled_labelsline 91Source documentation
Source specialization for its global independent comparison set
Y. The intersection appearing here is exactly the source'sY_i; all statistics are those of the actual density-dependent listed groups.theorem averaged_safe_sampled_labels (M : Matroid (Fin n)) (hE : M.E = Set.univ) (d : MainMasks n) (s : Fin n → Option ℤ) (i : ℤ) (Y : Set (Fin n)) (hI : M.Indep Y) : retainedFraction * (Y ∩ (trueGroup M d s i : Set (Fin n))).ncard - (trueGroup M d s i).card / (4 * densityThreshold) ≤ tripleMaskExpectation (fun _ => (1 : ℝ) / 4) (fun _ => thinningRate) (fun _ => thinningRate) univ (fun D C T => fairParityExpectation (fun p => (listedSafeStatistic M hE (2 ^ 100) (withMasks d D C T) s i Y (boolParity p) : ℝ))) := by …Mentions: OAI.MatroidProphet.MainMasks, OAI.MatroidProphet.retainedFraction, OAI.MatroidProphet.MainAlgorithm.trueGroup, OAI.MatroidProphet.densityThreshold, OAI.MatroidProphet.tripleMaskExpectation, OAI.MatroidProphet.thinningRate, OAI.MatroidProphet.fairParityExpectation, OAI.MatroidProphet.MainAlgorithm.listedSafeStatistic, OAI.MatroidProphet.MainAlgorithm.withMasks, OAI.MatroidProphet.boolParity