The two-space calculus of the main theorem's tail #
The tail of the vendored main theorem (Test/MainTheorem/SourceRoleRegister/* and
Test/MainTheorem/MainFormal.lean under MIPRE/Background/LIDT/MIPStarRE/LDT/) runs on the
strategy's own state, a state on ιA × ιB with Alice's measurements on ιA and Bob's on ιB. In
the port of planning/c6b-plan.md (milestone M13) that state is the strategy's bipartite model
M : MIPRE.BipartiteModel 𝒞 𝒜 ℬ, whose players' algebras 𝒜 and ℬ are abstract star-ordered
⋆-algebras, as in Co ProjStrat and in MIPRE.LIDT.Simul.SoundIn, not C⋆-algebras. This file
holds the two-space calculus the tail needs there. It has no vendored counterpart.
Why it is needed. The doubled model D(M) (Co/Doubling/) gives only role averages:
Doubling.bipartiteConsError_model says bc_D(X, Y) = ½ (bc_M(X¹, Y²) + bc_M(Y¹, X²)), so pulling a
one-sided relation back from D(M) costs a factor two, which breaks the vendored scalar cascade
into mainFormalError. Milestone M3 narrowed the vendored _heterogeneous lemmas of
Preliminaries to one carrier (planning/c6b-plan.md, "Departures in M3 and M5"); their
two-space forms are here, under their vendored names in the namespace MIPRE.LIDT.Co.TwoSpace.
Vocabulary.
- The placements
placeA M = π ∘ πAandplaceB M = π ∘ πBintoB(M.H), the vector statevecState M hψof a unitM.ψ, and the placed submeasurementsleftPlacedSubMeas M A,rightPlacedSubMeas M Band familiesplaceLeft M A,placeRight M B(the vendoredleftPlacedSubMeas (ιB := ιB)andIdxSubMeas.placeLeft). They areSubMeas.map, positivity transferring because a⋆-homomorphism between star-ordered rings is monotone. - Consistency is M2's two-space defect
MIPRE.LIDT.Co.bipartiteConsError M 𝒟 A B(Co/Test/StrategyBiProj/Measurements.lean): the vendoredConsRel ψ 𝒟 A B δis writtenbipartiteConsError M 𝒟 A B ≤ δ, and no two-spaceConsRelstructure is defined (planning/c6b-plan.md, "Same-space and bipartite quantities"). Distances are theVecStaterelations of the port onvecState M hψ, with joint operators inM.H →L[ℂ] M.H. bornProb_eq_ev,qBipartiteMatchMass_eq,qBipartiteConsDefect_eqandbipartiteConsError_eqtranslate M2's defect into that vocabulary, andqSDD_leftPlaced_eq_sum_norm_sq(with itsπBform) is the sum of norms with which M8's heterogeneous orthonormalizations conclude.
Completion in an abstract algebra. Co Preliminaries.completeAtOutcome is generic, but
completeAtOutcomeProj and ProjMeas.isPVMIn need a C⋆-algebra. In a finite pair the players'
algebras are ⋆-isomorphic to the commutants of the other player's operators
(IsFinitePair.equivA, equivB, MIPRE/Foundations/FinitePairOrder.lean), which are
C⋆-algebras; completeAtOutcomeProjA and completeAtOutcomeProjB complete there and come back
along the inverse. Positivity transfers along any ⋆-homomorphism of star-ordered rings, and
projectivity and the total are algebraic, so the order agreement of a finite pair is not used.
ProjMeas.isPVMIn_of_isFinitePair (in the namespace MIPRE.LIDT.Co.ProjMeas, for dot notation)
is the same transport for ProjMeas.isPVMIn.
New here #
Every declaration of this file is new; it has no vendored counterpart.
placeA,placeB,vecState,leftPlacedSubMeas,rightPlacedSubMeas,placeLeft,placeRightand their_apply,_outcome,_totalandvecState_Ψlemmas: the placements.bornProb_eq_ev,qBipartiteMatchMass_eq,qBipartiteConsDefect_eq,bipartiteConsError_eq,qSDD_leftPlaced_eq_sum_norm_sq,qSDD_rightPlaced_eq_sum_norm_sq: the bridges.bornProb_le_qform_πA,bornProb_le_qform_πB,qBipartiteConsDefect_le_one,bipartiteConsError_le_one_of_isProbability,bipartiteConsError_uniform_le_one: positivity.questionSDD_placeLeft_placeRight_le_two_questionConsistency,simeqToApprox_heterogeneous,two_questionConsistency_eq_questionSDD_of_projective,approxToSimeq_heterogeneous: the comparison of consistency and distance.consRel_of_matchGap,triangleSub_heterogeneous,triangleSub_right_heterogeneous,simeqTriangleInequality_heterogeneous: the triangle inequalities.qBipartiteMatchMass_postprocess_ge,qBipartiteConsDefect_postprocess_le,consRelDataProcessing_questionDependent: data processing.completeAtOutcomeProjA,completeAtOutcomeProjB, their_toMeasurementand_toSubMeasequations, andMIPRE.LIDT.Co.ProjMeas.isPVMIn_of_isFinitePair,…B: completion.
Not ported #
Nothing: the file has no vendored counterpart.
Placements #
The first player's placement a ↦ π (πA a) into the operators of M.H.
Equations
- MIPRE.LIDT.Co.TwoSpace.placeA M = M.π.comp M.πA
Instances For
The second player's placement b ↦ π (πB b) into the operators of M.H.
Equations
- MIPRE.LIDT.Co.TwoSpace.placeB M = M.π.comp M.πB
Instances For
The vector state of a unit state of M.
Equations
- MIPRE.LIDT.Co.TwoSpace.vecState M hψ = { Ψ := M.ψ, Ψ_norm := hψ }
Instances For
The Born probability is the expectation of the product of the placements.
A submeasurement of the first player's algebra, placed on M.H (the vendored
leftPlacedSubMeas (ιB := ιB)).
Equations
Instances For
The outcome operators of a left-placed submeasurement are placed.
The total of a left-placed submeasurement is placed.
A family of submeasurements of the first player's algebra, placed on M.H (the vendored
IdxSubMeas.placeLeft (ιB := ιB)).
Equations
Instances For
The squared distance of two placed submeasurements of the first player is the sum of norms
∑ₐ ‖π(πA(Aₐ − Pₐ)) ψ‖² with which M8's heterogeneous orthonormalization concludes.
A submeasurement of the second player's algebra, placed on M.H (the vendored
rightPlacedSubMeas (ιA := ιA)).
Equations
Instances For
The outcome operators of a right-placed submeasurement are placed.
The total of a right-placed submeasurement is placed.
A family of submeasurements of the second player's algebra, placed on M.H (the vendored
IdxSubMeas.placeRight (ιA := ιA)).
Equations
Instances For
The squared distance of two placed submeasurements of the second player is
∑ₐ ‖π(πB(Bₐ − Pₐ)) ψ‖².
Bridges to the two-space defect #
M2's two-space matching mass is the matching mass of the placed submeasurements.
M2's two-space consistency defect is the consistency defect of the placed submeasurements.
M2's averaged two-space defect is the averaged consistency defect of the placed families.
Positivity #
⟨ψ, (x ⊗ y) ψ⟩ ≤ ⟨ψ, (x ⊗ 1) ψ⟩ for 0 ≤ x and y ≤ 1: x ⊗ (1 − y) is a product of
commuting positive operators.
⟨ψ, (x ⊗ y) ψ⟩ ≤ ⟨ψ, (1 ⊗ y) ψ⟩ for x ≤ 1 and 0 ≤ y (bornProb_le_qform_πA for the
swapped model).
A two-space consistency defect is at most 1 at a unit state.
Under a probability question distribution, the averaged two-space defect is at most 1.
Under the uniform question distribution, the averaged two-space defect is at most 1 (the
trivial branch of the main theorem).
Consistency and distance #
For measurements A of 𝒜 and B of ℬ, the squared distance of their placements is at
most twice their two-space consistency defect: the per-question core of
simeqToApprox_heterogeneous, which is BipartiteModel.xSqNorm_sum_le_two_mul.
Heterogeneous prop:simeq-to-approx: two-space consistency of measurements A of 𝒜 and
B of ℬ at δ gives the state-dependent distance 2δ between their placements.
For projective measurements A of 𝒜 and B of ℬ, twice their two-space consistency
defect is the squared distance of their placements: the two placements commute and each is
idempotent, so (Aₐ ⊗ 1 − 1 ⊗ Bₐ)² = Aₐ ⊗ 1 + 1 ⊗ Bₐ − 2 Aₐ ⊗ Bₐ. Algebraic: no C⋆-structure
on 𝒜 or ℬ is used.
Heterogeneous projective converse of prop:simeq-to-approx: for projective measurements
A of 𝒜 and B of ℬ, the state-dependent distance 2δ between their placements gives
two-space consistency at δ.
Triangle inequalities #
The common substitution step of the two-space triangleSub family (Co
Preliminaries.consRel_of_matchGap): if bipartiteConsError M 𝒟 A B ≤ δ, the matching masses
of (A, B) and (A', B') differ by at most √(s q) at each question, and the total overlap of
(A', B') exceeds that of (A, B) by at most e q, then the defect of (A', B') is at most
δ + √ε + η for 𝔼 s ≤ ε and 𝔼 e ≤ η.
Heterogeneous left substitution (prop:triangle-sub): if measurements A of 𝒜 and a
submeasurement C of ℬ are consistent at δ, and the placements of A and of a measurement
B of 𝒜 are at state-dependent distance ε, then B and C are consistent at δ + √ε.
Heterogeneous right substitution: if a submeasurement A of 𝒜 and a measurement B of
ℬ are consistent at δ, and the placements of B and of a measurement D of ℬ are at
state-dependent distance ε, then A and D are consistent at δ + √ε.
Heterogeneous prop:simeq-triangle-inequality, with the vendored constant: for measurements
A, C of 𝒜 and B, D of ℬ, consistency of (A, B) at ε, of (C, B) at δ and of
(C, D) at γ gives consistency of (A, D) at ε + 2√(δ + γ). As in Co
Preliminaries.simeqTriangleInequality: compare the placements of B and D through C, then
substitute on the right.
Data processing #
Postprocessing two submeasurements, of 𝒜 and of ℬ, by the same readout map can only
increase their two-space matching mass: the new terms are the old ones plus Born probabilities
of positive elements within each fibre.
Postprocessing two submeasurements, of 𝒜 and of ℬ, by the same readout map can only
decrease their two-space consistency defect: the totals are kept.
Question-dependent postprocessing preserves two-space consistency (the two-space form of Co
Preliminaries.consRelDataProcessing_questionDependent).
Completion in the players' algebras of a finite pair #
Complete a projective submeasurement of the first player's algebra of a finite pair at a
distinguished outcome, to a projective measurement: Co Preliminaries.completeAtOutcomeProj in
the commutant IsFinitePair.equivA identifies 𝒜 with, a C⋆-algebra, carried back along the
inverse.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The measurement of completeAtOutcomeProjA hM P a0 is the canonical completion
completeAtOutcome P.toSubMeas a0 in 𝒜.
The submeasurement of completeAtOutcomeProjA hM P a0 is that of completeAtOutcome.
A projective measurement of the first player's algebra of a finite pair is a projective
measurement of the repository (MIPRE.IsPVMIn): Co ProjMeas.isPVMIn in the commutant
IsFinitePair.equivA identifies 𝒜 with, pulled back along isPVMIn_map_equiv_iff.
Complete a projective submeasurement of the second player's algebra of a finite pair at a
distinguished outcome, through IsFinitePair.equivB.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The measurement of completeAtOutcomeProjB hM P a0 is the canonical completion
completeAtOutcome P.toSubMeas a0 in ℬ.
The submeasurement of completeAtOutcomeProjB hM P a0 is that of completeAtOutcome.
A projective measurement of the second player's algebra of a finite pair is a projective
measurement of the repository, through IsFinitePair.equivB.