Section 3 — Definitions #
Core definitions for the low individual degree test: evaluation families,
matching mass, consistency defect, and test-passing predicates. This is the counterpart of
MIPRE/Background/LIDT/MIPStarRE/LDT/Test/Defs.lean in the port of planning/c6b-plan.md
(milestone M0, section "Port conventions").
The evaluation families (evaluateAt, polynomialEvaluationFamily, ...) are generic over the
ordered ⋆-ring R of Co/Basic/SubMeasurementCore.lean. The ev-level defects and relations
are used with dot notation on the state: the vendored qSDD ψ A B is S.qSDD A B,
SDDRel ψ 𝒟 A B δ is S.SDDRel 𝒟 A B δ.
- A same-space quantity (
qMatchMass,qConsDefect,qSDDCore,qSDD,qSDDOp,qSSCDefect,consError,sddError,sddErrorOp,sscError,subMeasMass,idxSubMeasMass,bndError,SDDRel,SDDOpRel,SSCRel,CompletenessAtLeast,BoundedByOperator) uses only the state, so it is aVecStatedeclaration (Co/Basic/QuantumState.lean), about joint operators inK →L[ℂ] K. It applies to any vector state, with no swap symmetry: the vendored uses with a state on one space, a reduced state or a state tensored with an ancilla (MakingMeasurementsProjective) port without building a symmetric model; andS.qSDD A BforS : SymModel 𝔓 KisS.toVecState.qSDD A B. - A bipartite quantity (
qBipartiteMatchMass,qBipartiteConsDefect,bipartiteConsError,ConsRel,qBipartiteSSCDefect,bipartiteSSCError,BipartiteSSCRel) places local families in𝔓on the two factors throughS.opTensor, so it is aSymModeldeclaration. The two-spaceProjStratofCo/Test/StrategyCore.leanhas no counterpart of these: see there.
As everywhere in the port, the normalization hypothesis hψ : ψ.IsNormalized of the vendored
bounds is dropped: V.ev 1 = 1 is a theorem of every vector state.
New here #
Three bridges to the repository calculus, through V.toStateModel and S.toBipartite
(Co/Basic/QuantumState.lean):
VecState.qSDDCore_eq_sum_snorm_sq:qSDDCoreis∑ₐ ‖(Aₐ - Bₐ) Ψ‖²;SymModel.bipartiteConsError_eq_inconsistency: for measurements, the bipartite consistency error isMIPRE.BipartiteModel.inconsistency(MIPRE/Foundations/ModelStrategy.lean) of the model, weighted by the distribution; its per-question form, for sub-measurements, isSymModel.qBipartiteConsDefect_eq_sum_ne, the off-diagonal Born mass;SymModel.sddError_liftLeft_liftRight_eq_xPovmDist: for measurements, the squared distance of the left and right lifts isMIPRE.BipartiteModel.xPovmDist(MIPRE/Foundations/CrossConsistency.lean).
Not ported #
Every declaration of the vendored file has a counterpart here.
Evaluate a polynomial-valued submeasurement at a point.
Equations
- MIPRE.LIDT.Co.evaluateAt params u G = MIPRE.LIDT.Co.postprocess G fun (g : MIPStarRE.LDT.Polynomial params) => g.toFun u
Instances For
Evaluation after adjoining an unused coordinate agrees with evaluation before adjoining that coordinate.
View a global polynomial submeasurement as a point-indexed answer family.
Equations
- MIPRE.LIDT.Co.polynomialEvaluationFamily params G u = MIPRE.LIDT.Co.evaluateAt params u G
Instances For
View a global polynomial measurement as a point-indexed answer measurement family.
The submeasurement-valued polynomialEvaluationFamily is the form used by most
consistency statements. The heterogeneous triangle step in the final theorem
uses complete measurements, so this version keeps the same postprocessing while
retaining the total-mass proof.
Equations
- MIPRE.LIDT.Co.polynomialEvaluationMeasurementFamily params G u = { toSubMeas := MIPRE.LIDT.Co.evaluateAt params u G.toSubMeas, total_eq_one := ⋯ }
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Namespace-compatible form of polynomialEvaluationMeasurementFamily.
This name is used by the two-space final-theorem route, where the surrounding
theorems live in the Test namespace.
Equations
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Evaluate an indexed slice family at a point (u, x) in F_q^{m+1}.
Equations
- MIPRE.LIDT.Co.evaluateFiberFamilyAtNextPoint params G u = MIPRE.LIDT.Co.evaluateAt params (MIPStarRE.LDT.truncatePoint params u) (G (MIPStarRE.LDT.pointHeight params u))
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Postprocessing preserves totals #
Postprocessing preserves the total operator.
An average against a distribution, written over the whole question type.
Questionwise defects #
Questionwise matching mass ∑_a ⟨Ψ, A_a B_a Ψ⟩, summed over outcomes.
Instances For
Questionwise off-diagonal mass surrogate for consistency.
Equations
- V.qConsDefect A B = max 0 (V.ev (A.total * B.total) - V.qMatchMass A B)
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Questionwise squared-distance defect.
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Questionwise squared-distance defect.
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State-dependent distance for raw operator families.
Matches the paper's ≈_δ for arbitrary operator families.
This keeps the raw-family API separate while sharing the same core formula as
qSDD.
Instances For
Questionwise strong self-consistency defect.
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Averaged defects #
Averaged off-diagonal mass for consistency statements.
Equations
- V.consError 𝒟 A B = MIPStarRE.LDT.avgOver 𝒟 fun (q : Question) => V.qConsDefect (A q) (B q)
Instances For
Averaged squared distance for ≈_δ.
Equations
- V.sddError 𝒟 A B = MIPStarRE.LDT.avgOver 𝒟 fun (q : Question) => V.qSDD (A q) (B q)
Instances For
Averaged squared distance for raw operator families.
Equations
- V.sddErrorOp 𝒟 A B = MIPStarRE.LDT.avgOver 𝒟 fun (q : Question) => V.qSDDOp (A q) (B q)
Instances For
Averaged defect in strong self-consistency.
Equations
- V.sscError 𝒟 A = MIPStarRE.LDT.avgOver 𝒟 fun (q : Question) => V.qSSCDefect (A q)
Instances For
Total mass of a submeasurement on the state, computed from the concrete total operator.
Equations
- V.subMeasMass A = V.ev A.total
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Averaged total mass of an indexed submeasurement.
Equations
- V.idxSubMeasMass 𝒟 A = MIPStarRE.LDT.avgOver 𝒟 fun (q : Question) => V.subMeasMass (A q)
Instances For
Defect in domination by an operator witness, measured at the expectation-value level.
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Relations #
State-dependent distance relation.
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State-dependent distance relation for raw operator families.
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Strong self-consistency relation.
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Completeness statement for a submeasurement.
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Boundedness statement witnessed by an operator.
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Nonnegativity lemmas for defect measures #
The squared-distance defect is nonneg since each summand is ⟨Ψ, M†M Ψ⟩ ≥ 0.
The averaged squared-distance error is nonneg.
Self-distance #
The self-distance qSDD A A is zero.
The averaged self-distance sddError 𝒟 A A is zero.
Bridges to the repository calculus #
The squared-distance defect is a sum of squared state norms:
qSDDCore A B = ∑ₐ ‖(Aₐ - Bₐ) Ψ‖², each term being V.toStateModel.snorm (Aₐ - Bₐ) ^ 2
(toStateModel_snorm).
Bipartite defects #
Bipartite matching mass ∑_a ⟨Ψ, (A_a ⊗ B_a) Ψ⟩, with A on the first factor and B on
the second (S.opTensor).
Instances For
Bipartite questionwise consistency defect.
In the paper (Definition 4.8), the consistency of A on H_A and B on
H_B for a shared state |ψ⟩ ∈ H_A ⊗ H_B is:
E_x ∑_{a≠b} ⟨ψ| A^x_a ⊗ B^x_b |ψ⟩ ≤ δ
which equals
max 0 (⟨ψ| A_total ⊗ B_total |ψ⟩ − ∑_a ⟨ψ| A_a ⊗ B_a |ψ⟩)
(qBipartiteConsDefect_eq_sum_ne).
Equations
- S.qBipartiteConsDefect A B = max 0 (S.ev (S.opTensor A.total B.total) - S.qBipartiteMatchMass A B)
Instances For
Averaged bipartite off-diagonal mass for consistency statements.
Equations
- S.bipartiteConsError 𝒟 A B = MIPStarRE.LDT.avgOver 𝒟 fun (q : Question) => S.qBipartiteConsDefect (A q) (B q)
Instances For
Bridge lemma: the bipartite consistency defect equals the same-space
qConsDefect applied to the left/right-placed submeasurements.
Bridge lemma: averaged bipartite consistency equals the same-space
consError applied to the left/right-placed families.
Relations #
Consistency relation (bipartite, paper Definition 4.8).
Alice's submeasurement A acts on the first factor and Bob's submeasurement B on the
second. The relation encodes
E_{x ∼ D} ∑_{a≠b} ⟨ψ| A^x_a ⊗ B^x_b |ψ⟩ ≤ δ.
Instances For
Bipartite questionwise strong self-consistency defect.
This is the paper's SSC condition (Definition 4.3/4.4):
max 0 (∑ₐ ev (Aₐ ⊗ I) − ∑ₐ ev (Aₐ ⊗ Aₐ)).
It measures the gap between the total mass on one register and the
diagonal cross-register overlap.
Equations
Instances For
Averaged bipartite SSC defect.
Equations
- S.bipartiteSSCError 𝒟 A = MIPStarRE.LDT.avgOver 𝒟 fun (q : Question) => S.qBipartiteSSCDefect (A q)
Instances For
Bipartite strong self-consistency relation (paper's definition).
Uses the cross-register overlap ∑ₐ ev (Aₐ ⊗ Aₐ) rather than
the local square ∑ₐ ev (Aₐ² ⊗ I).
Instances For
Nonnegativity lemmas for defect measures #
The bipartite consistency defect is nonneg by definition (max 0 _).
The averaged bipartite consistency error is nonneg.
The bipartite matching mass is nonnegative because each summand is the expectation of a positive tensor product.
A bipartite consistency defect is at most 1 (the state is normalized).
Under a probability question distribution, the averaged bipartite consistency
error is bounded by 1.
Under the uniform question distribution, the averaged bipartite consistency
error is bounded by 1.
The bipartite strong self-consistency defect is nonneg by definition (max 0 _).
The averaged bipartite strong self-consistency error is nonneg.
Bridges to the repository calculus #
The bipartite consistency defect is the off-diagonal Born mass
∑_{a ≠ b} ⟨Ψ, (A_a ⊗ B_b) Ψ⟩, for any two sub-measurements: the max 0 of the definition
is inactive, since the total overlap is the sum of all the Born weights.
The bipartite consistency error of two measurement families is the inconsistency of the
model (MIPRE.BipartiteModel.inconsistency), weighted by the question distribution.
The squared distance of the left and right lifts of two measurement families is the
cross-party distance of the model (MIPRE.BipartiteModel.xPovmDist), weighted by the question
distribution: the vendored A ⊗ I ≈_δ I ⊗ B is the appendix's A ⊗ Id ≃_δ Id ⊗ B.