Rational support elimination certificates
Abstract
A proposed null direction is checked using exact rational identities and cross-multiplied ratio inequalities. Acceptance implies nonnegative weights, unchanged moments, and strict support descent.
Definition 1.1 (Computable raw-vector support).
Lean statement: D5/S0/Certificates/RationalMomentElimination.activeAtoms
Formalization. D5/S0/Certificates/RationalMomentElimination.activeAtoms (✓ std3).
Source. Repository-derived.
Commentary.
Enumerates exactly the nonzero weights before packaging the vector as a normalized finite response law.
Definition 1.2 (Data-only elimination payload).
Lean statement: D5/S0/Certificates/RationalMomentElimination.EliminationStep
Formalization. D5/S0/Certificates/RationalMomentElimination.EliminationStep (✓ std3).
Source. Repository-derived.
Commentary.
The payload contains a rational direction array and one pivot index. It contains no proof fields or trusted solver output.
Definition 1.3 (Finite arithmetic validity conditions).
Lean statement: D5/S0/Certificates/RationalMomentElimination.ValidStep
Formalization. D5/S0/Certificates/RationalMomentElimination.ValidStep (✓ std3).
Source. Repository-derived.
Commentary.
Checks nonnegative input, positive pivot, zero normalization and feature directions, no motion at inactive atoms, and all ratio comparisons.
Definition 1.4 (Exact executable validator).
Lean statement: D5/S0/Certificates/RationalMomentElimination.checkStep
Formalization. D5/S0/Certificates/RationalMomentElimination.checkStep (✓ std3).
Source. Repository-derived.
Commentary.
Decides the finite rational conditions. No threshold or floating-point comparison is used.
Theorem 1.5 (Validator characterization).
Lean statement: D5/S0/Certificates/RationalMomentElimination.checkStep_eq_true_iff
Proof. Machine-checked in Lean as D5/S0/Certificates/RationalMomentElimination.checkStep_eq_true_iff (✓ std3). ∎
Source. Repository-derived.
Commentary.
Boolean acceptance is equivalent to the semantic arithmetic conditions used by the preservation proofs.
Definition 1.6 (Rational boundary update).
Lean statement: D5/S0/Certificates/RationalMomentElimination.eliminate
Formalization. D5/S0/Certificates/RationalMomentElimination.eliminate (✓ std3).
Source. Repository-derived.
Commentary.
Subtracts the pivot ratio times the direction. The checked pivot has a strictly positive denominator.
Theorem 1.7 (Retain nonnegative weights).
Lean statement: D5/S0/Certificates/RationalMomentElimination.validStep_nonnegative
Proof. Machine-checked in Lean as D5/S0/Certificates/RationalMomentElimination.validStep_nonnegative (✓ std3). ∎
Source. Repository-derived.
Commentary.
Positive direction coordinates are bounded by the certified pivot ratio; nonpositive direction coordinates cannot lower the weights.
Theorem 1.8 (Preserve total mass).
Lean statement: D5/S0/Certificates/RationalMomentElimination.validStep_total
Proof. Machine-checked in Lean as D5/S0/Certificates/RationalMomentElimination.validStep_total (✓ std3). ∎
Source. Repository-derived.
Commentary.
The direction sums to zero, so the rational update preserves total mass exactly.
Theorem 1.9 (Preserve every retained moment).
Lean statement: D5/S0/Certificates/RationalMomentElimination.validStep_moment
Proof. Machine-checked in Lean as D5/S0/Certificates/RationalMomentElimination.validStep_moment (✓ std3). ∎
Source. Repository-derived.
Commentary.
Uses the existing linearObjective semantics. Every checked zero directional moment remains unchanged after the update.
Theorem 1.10 (Respect hard support exclusions).
Lean statement: D5/S0/Certificates/RationalMomentElimination.validStep_zero_stays_zero
Proof. Machine-checked in Lean as D5/S0/Certificates/RationalMomentElimination.validStep_zero_stays_zero (✓ std3). ∎
Source. Repository-derived.
Commentary.
An initially zero atom cannot acquire mass. The condition is separate from preservation of the nominated moments.
Theorem 1.11 (Remove the chosen pivot exactly).
Lean statement: D5/S0/Certificates/RationalMomentElimination.validStep_pivot_zero
Proof. Machine-checked in Lean as D5/S0/Certificates/RationalMomentElimination.validStep_pivot_zero (✓ std3). ∎
Source. Repository-derived.
Commentary.
The pivot weight cancels identically at the selected ratio, without numerical tolerances.
Theorem 1.12 (Strict support descent).
Lean statement: D5/S0/Certificates/RationalMomentElimination.validStep_support
Proof. Machine-checked in Lean as D5/S0/Certificates/RationalMomentElimination.validStep_support (✓ std3). ∎
Source. Repository-derived.
Commentary.
The new support is a subset of the old support with strictly smaller cardinality. Ties may remove several atoms.
Theorem 1.13 (Maximal feasible move along the direction).
Lean statement: D5/S0/Certificates/RationalMomentElimination.validStep_maximal_rate
Proof. Machine-checked in Lean as D5/S0/Certificates/RationalMomentElimination.validStep_maximal_rate (✓ std3). ∎
Source. Repository-derived.
Commentary.
Any larger move makes the certified pivot negative. This is a linewise maximality statement, not an optimality claim for the causal query.
References
- Truth anchor:
D5/S0/Certificates/RationalMomentElimination.EliminationStep - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.ValidStep - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.activeAtoms - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.checkStep - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.checkStep_eq_true_iff - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.eliminate - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.validStep_maximal_rate - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.validStep_moment - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.validStep_nonnegative - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.validStep_pivot_zero - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.validStep_support - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.validStep_total - Truth anchor:
D5/S0/Certificates/RationalMomentElimination.validStep_zero_stays_zero - Dependency: D5/S0/Certificates/LinearObjectiveDual