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Complexitylib.Algebraic.LowerBound.Cutwidth.Extractor.CorrelationBreaker.Affine.Iteration.Parameters

Concrete global reserves for repeated affine rounds #

The unchanged first-phase chooser, at target target + clog₂(t+1) + 1, pays every round after doubling its original-left entropy reserve. The theorems account for the full initial transcript and two left/four right short-message families per round. All four worst-case subset reserves hold without additional numerical hypotheses.

These are finite parameter deductions for the subset-doubling construction of Chattopadhyay--Liao, Extractors for Sum of Two Sources (2021), Theorem 6.1, https://arxiv.org/abs/2110.12652. They do not assert source capacity for every input width or replace the actual statistical iteration proof.

The number of rounds is no larger than the number of tampered copies.

The doubled subset capacity covers every tampered index, including the zero-copy case.

A single original-left budget includes the complete initial and repeated observations.

The existing right-source width pays the complete initial and repeated observations.

Cumulative left transcript losses never exhaust the original source reserve.

Cumulative right transcript losses never exceed the original uniform width.

The first short extraction has enough remaining original-right entropy in every round.

The actual long row pays the middle extraction and every selected short output.

The recovery call pays all three right-message families and the selected outputs.

The final extraction pays the current selected long outputs and both left observations.

Exact dyadic mass after the initial left transcript and two message families per round.

Exact dyadic mass after the initial right transcript and four message families per round.

theorem Algebraic.Cutwidth.Extractor.affineIterationParameters_error_budget (t target : ℕ) :
have R := affineIterationRounds t; have σ := affineIterationTarget t target; 2 ^ R * (2 ^ σ)⁻¹ + 8 * (2 ^ R - 1) * (2 ^ affinePhaseOneLocalError σ)⁻¹ ≤ (2 ^ target)⁻¹

The complete ρ ↦ 2ρ + 8 * 2⁻ᵉ recurrence fits the requested final error.

The doubled source reserve also satisfies the original first-phase entropy hypothesis.

The full original-left entropy reserve remains a fixed polynomial in the chooser base.