Context
The reduction spends exponent slack on field size, large-support separation, shifted valuations, and reconstruction. Keeping those resources separate exposes the exact feasibility boundary of this proof template.
Hypotheses and scope
- The retained output-size relation is M = O(N q^2).
- The retained valuation horizon grows as K^5, and reconstruction uses K^2 T.
- All exponent inequalities are strict and the field exponent Q is nonnegative.
Proof or evidence
The inequalities imply Q > 2 + 7 kappa and then (1 - 28c)Q > 9 + 14c. Lean proves both real witnesses below 1/28 and impossibility at or above 1/28.
Verification notes
The algebraic elimination, strict-inequality direction, nonnegative-Q boundary, governed claim, Lean theorem endpoints, and independent review note were reconciled against the pinned source.
Limitations
- The value 1/28 is an unattained supremum for this retained architecture, not a universal CVP-hardness barrier.
- The general theorem checks the resource inequalities; it is not one uniformly parameterized executable Lean reduction for every c below 1/28.
- No novelty or external specialist review is claimed.
Notes
The fork's retained_resource_inequalities_impossible_at_or_above_frontier and frontier_real_witnesses theorems prove necessity and natural-number sufficiency. The paper uses this frontier in its mathematical reduction for every fixed 0 <= c < 1/28; the complete executable Lean reduction is concrete at c=1/30. The 1/28 value is the supremum of the retained one-hot, K^5 valuation-horizon, and K^2T reconstruction inequalities; it is not a lower bound on all direct GapCVP reductions and is not attained by this strict system.