OAI/Combinatorics/LowSpaceSubsetSum/Counting/HalfOrientations.lean
5 declarations, 0 contain sorry, 0 declared as axioms
Orienting three pairs of mixer halves
The orientations here describe the conditional sign experiment; they are analysis variables, not extra random draws made by the algorithm. Every unordered pair of halves has a good orientation by deficiency superadditivity. A uniform vector of three orientations therefore succeeds with probability at least one eighth. The product-space bound also permits an arbitrary preceding event depending on the unordered pairs.
- theorem
OAI.LowSpaceSubsetSum.finiteUniformProbability_ge_card_inv_of_existsline 18 - def
OAI.LowSpaceSubsetSum.orientedHalfline 31 - theorem
OAI.LowSpaceSubsetSum.exists_good_half_orientationline 34 - theorem
OAI.LowSpaceSubsetSum.three_half_orientations_probabilityline 46 - theorem
OAI.LowSpaceSubsetSum.finiteUniformProbability_joint_orientationline 66Source documentation
Counting one successful orientation over every preceding good outcome gives the joint lower bound without assuming that the preceding event and the successful orientation event are independent.
theorem finiteUniformProbability_joint_orientation {Ω : Type*} [Fintype Ω] [Nonempty Ω] (E : Ω → Prop) (G : Ω → (Fin 3 → Bool) → Prop) (hG : ∀ ω, E ω → ∃ b, G ω b) : finiteUniformProbability E / 8 ≤ finiteUniformProbability (fun p : Ω × (Fin 3 → Bool) => E p.1 ∧ G p.1 p.2) := by …