OAI/Combinatorics/LowSpaceSubsetSum/Counting/Representatives.lean
13 declarations, 0 contain sorry, 0 declared as axioms
Many distinct weights at one prescribed cardinality
The first representative-selection step in the low-deficiency survival proof. Complementation allows the selected cardinality to be at most half the domain. All cardinalities count distinct integer weights, not subset occurrences.
- def
OAI.LowSpaceSubsetSum.sumsAtSizeline 23 - theorem
OAI.LowSpaceSubsetSum.mem_sumsAtSizeline 26 - theorem
OAI.LowSpaceSubsetSum.weight_complementline 31 - theorem
OAI.LowSpaceSubsetSum.sumsAtSize_complementline 41 - theorem
OAI.LowSpaceSubsetSum.sumsAtSize_complement_cardline 62 - theorem
OAI.LowSpaceSubsetSum.distinctSumCount_le_sum_sizesline 70 - theorem
OAI.LowSpaceSubsetSum.exists_many_distinct_weights_at_sizeline 83Source documentation
Pigeonhole selection of one size, followed by complementation if necessary.
theorem exists_many_distinct_weights_at_size (a : ι → ℤ) (V : Finset ι) : ∃ k ≤ V.card / 2, distinctSumCount a V ≤ (V.card + 1) * (sumsAtSize a V k).card := by …Mentions: OAI.LowSpaceSubsetSum.distinctSumCount, OAI.LowSpaceSubsetSum.sumsAtSize
- theorem
OAI.LowSpaceSubsetSum.two_pow_card_sub_deficiencyline 99Source documentation
The exact exponential form of the distinct-weight count.
theorem two_pow_card_sub_deficiency (a : ι → ℤ) (V : Finset ι) : (2 : ℝ) ^ ((V.card : ℝ) - deficiency a V) = distinctSumCount a V := by …Mentions: OAI.LowSpaceSubsetSum.deficiency, OAI.LowSpaceSubsetSum.distinctSumCount
- theorem
OAI.LowSpaceSubsetSum.exists_representative_sizeline 105Source documentation
The representation proof's first distinct-weight lower bound.
theorem exists_representative_size (a : ι → ℤ) (V : Finset ι) : ∃ k ≤ V.card / 2, (2 : ℝ) ^ ((V.card : ℝ) - deficiency a V) / (V.card + 1) ≤ (sumsAtSize a V k).card := by …Mentions: OAI.LowSpaceSubsetSum.deficiency, OAI.LowSpaceSubsetSum.sumsAtSize
- theorem
OAI.LowSpaceSubsetSum.sumsAtSize_card_le_third_entropyline 119Source documentation
Subsets of size at most one third cannot supply more than the corresponding entropy bound, regardless of repeated values in the input.
theorem sumsAtSize_card_le_third_entropy (a : ι → ℤ) (V : Finset ι) {k : ℕ} (hV : 0 < V.card) (hk : 3 * k ≤ V.card) : ((sumsAtSize a V k).card : ℝ) ≤ (2 : ℝ) ^ ((V.card : ℝ) * binaryEntropy (1 / 3)) := by …Mentions: OAI.LowSpaceSubsetSum.sumsAtSize, OAI.LowSpaceSubsetSum.binaryEntropy
- theorem
OAI.LowSpaceSubsetSum.exists_representative_size_rangeline 142Source documentation
Once a block supplies enough distinct sums, the size selected by pigeonhole lies strictly above one third of that block and at most one half. These are exactly the guesses used by the representation trial.
theorem exists_representative_size_range (a : ι → ℤ) (V : Finset ι) (hV : 0 < V.card) (hcount : (2 : ℝ) ^ ((V.card : ℝ) * binaryEntropy (1 / 3)) < (distinctSumCount a V : ℝ) / (V.card + 1)) : ∃ k, V.card < 3 * k ∧ k ≤ V.card / 2 ∧ (distinctSumCount a V : ℝ) / (V.card + 1) ≤ (sumsAtSize a V k).card := by …Mentions: OAI.LowSpaceSubsetSum.binaryEntropy, OAI.LowSpaceSubsetSum.distinctSumCount, OAI.LowSpaceSubsetSum.sumsAtSize
- theorem
OAI.LowSpaceSubsetSum.eventually_small_deficiency_size_rangeline 157Source documentation
The small-deficiency regime eventually excludes the lower third. The margin
1/1500is absolute, so this assertion is uniform in the weights.theorem eventually_small_deficiency_size_range : ∀ᶠ m : ℕ in Filter.atTop, ∀ (a : ι → ℤ) (V : Finset ι), V.card = m → deficiency a V ≤ (33 / 500 : ℝ) * m → ∃ k, V.card < 3 * k ∧ k ≤ V.card / 2 ∧ (2 : ℝ) ^ ((V.card : ℝ) - deficiency a V) / (V.card + 1) ≤ (sumsAtSize a V k).card := by …Mentions: OAI.LowSpaceSubsetSum.deficiency, OAI.LowSpaceSubsetSum.sumsAtSize
- theorem
OAI.LowSpaceSubsetSum.half_mixer_deficiency_thresholdline 195Source documentation
The manuscript's absolute threshold makes
tau = .0078nat most.066sfor every size-smixer half; the floor inmis included.theorem half_mixer_deficiency_threshold {n : ℕ} (hn : 2200 ≤ n) : (39 / 5000 : ℝ) * n ≤ (33 / 500 : ℝ) * (mixerSize n / 2 : ℕ) := by …Mentions: OAI.LowSpaceSubsetSum.mixerSize