Documentation

MIPRE.Background.LIDT.Co.Basic.SubMeasurementCore

Core submeasurement structures for the low individual degree test #

Foundational measurement, submeasurement, and projective-measurement structures: the counterpart of MIPRE/Background/LIDT/MIPStarRE/LDT/Basic/SubMeasurementCore.lean in the port of planning/c6b-plan.md (milestone M0, section "Port conventions").

The vendored structures have their effects in the matrix algebra Op ι. Here they are generic over an ordered ⋆-ring R ([Ring R] [StarRing R] [PartialOrder R]), with the vendored field names verbatim: local families take R = 𝔓, the local C*-algebra of a symmetric model, and joint families R = K →L[ℂ] K. Each lemma asks for what its proof uses: positivity facts for a star-ordered ring, and the two projective lemmas (ProjSubMeas.outcome_mul_total_eq_outcome, ProjSubMeas.outcome_orthogonal) for a C*-algebra, where the C*-identity star x * x = 0 → x = 0 (CStarRing.star_mul_self_eq_zero_iff) replaces the vendored Matrix.conjTranspose_mul_self_eq_zero.

New here #

Not ported #

Every declaration of the vendored file has a counterpart here.

structure MIPRE.LIDT.Co.SubMeas (α : Type u_1) [Fintype α] (R : Type u_2) [Ring R] [StarRing R] [PartialOrder R] :
Type (max u_1 u_2)

A paper-local submeasurement with outcomes in α and effects in the ordered ⋆-ring R.

There is intentionally no global Inhabited instance: the zero family satisfies these raw axioms, but using it as an ambient default would silently turn later arguments into vacuous submeasurement statements.

  • outcome : α → R
  • total : R
  • outcome_pos (a : α) : 0 ≤ self.outcome a
  • sum_eq_total : ∑ a : α, self.outcome a = self.total
  • total_le_one : self.total ≤ 1
Instances For
    structure MIPRE.LIDT.Co.Measurement (α : Type u_1) (R : Type u_2) [Fintype α] [Ring R] [StarRing R] [PartialOrder R] extends MIPRE.LIDT.Co.SubMeas α R :
    Type (max u_1 u_2)

    A paper-local measurement: a POVM whose positive effects sum to the identity.

    Instances For
      theorem MIPRE.LIDT.Co.Measurement.trivialDistinguishedOutcome_outcome_pos {α : Type u_1} {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (a₀ a : α) :
      0 ≤ if a = a₀ then 1 else 0

      For a trivial distinguished-outcome measurement, every outcome operator is positive: 0 ≤ if a = a₀ then 1 else 0.

      noncomputable def MIPRE.LIDT.Co.Measurement.trivialDistinguishedOutcome {α : Type u_1} {R : Type u_2} [Fintype α] [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (a₀ : α) :

      ⚠️ DEGENERATE — Construct a trivial measurement where only the distinguished outcome a₀ is the identity and all other outcomes are zero.

      This is a valid POVM but highly degenerate: it is only used in vacuous fallback branches of the proof where the error bound is ≥ 1 (see the vendored Test/MainTheorem.lean:mainFormal_trivial_witness).

      Call this function explicitly with a chosen outcome. There is intentionally no ambient Inhabited (Measurement α R) instance: choosing a hidden default : α would make degenerate witnesses available to paper-facing existential statements without displaying the selected outcome.

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      • One or more equations did not get rendered due to their size.
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        structure MIPRE.LIDT.Co.ProjSubMeas (α : Type u_1) [Fintype α] (R : Type u_2) [Ring R] [StarRing R] [PartialOrder R] extends MIPRE.LIDT.Co.SubMeas α R :
        Type (max u_1 u_2)

        A paper-local projective submeasurement (each effect is idempotent).

        There is intentionally no global Inhabited instance: any such default would again collapse to the degenerate zero family.

        Instances For
          structure MIPRE.LIDT.Co.ProjMeas (α : Type u_1) (R : Type u_2) [Fintype α] [Ring R] [StarRing R] [PartialOrder R] extends MIPRE.LIDT.Co.Measurement α R :
          Type (max u_1 u_2)

          A paper-local projective measurement (complete POVM + projective).

          Instances For

            For a trivial distinguished-outcome projective measurement, every outcome operator is idempotent.

            noncomputable def MIPRE.LIDT.Co.ProjMeas.trivialDistinguishedOutcome {α : Type u_1} {R : Type u_2} [Fintype α] [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (a₀ : α) :

            ⚠️ DEGENERATE — Construct a trivial projective measurement where only the distinguished outcome a₀ is the identity and all other outcomes are zero.

            This is a valid projective POVM but highly degenerate: see the discussion at Measurement.trivialDistinguishedOutcome. As for Measurement, there is intentionally no ambient Inhabited (ProjMeas α R) instance.

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              Derived properties #

              theorem MIPRE.LIDT.Co.SubMeas.ext {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] {A B : SubMeas α R} (houtcome : ∀ (a : α), A.outcome a = B.outcome a) (htotal : A.total = B.total) :
              A = B

              Two submeasurements are equal when they have the same outcome operators and the same total operator.

              theorem MIPRE.LIDT.Co.SubMeas.ext_iff {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] {A B : SubMeas α R} :
              A = B ↔ (∀ (a : α), A.outcome a = B.outcome a) ∧ A.total = B.total
              theorem MIPRE.LIDT.Co.Measurement.ext {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] {A B : Measurement α R} (houtcome : ∀ (a : α), A.outcome a = B.outcome a) :
              A = B

              Two measurements are equal when they have the same outcome operators.

              theorem MIPRE.LIDT.Co.Measurement.ext_iff {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] {A B : Measurement α R} :
              A = B ↔ ∀ (a : α), A.outcome a = B.outcome a
              theorem MIPRE.LIDT.Co.ProjMeas.ext {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] {A B : ProjMeas α R} (houtcome : ∀ (a : α), A.outcome a = B.outcome a) :
              A = B

              Two projective measurements are equal when they have the same outcome operators.

              theorem MIPRE.LIDT.Co.ProjMeas.ext_iff {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] {A B : ProjMeas α R} :
              A = B ↔ ∀ (a : α), A.outcome a = B.outcome a
              def MIPRE.LIDT.Co.SubMeas.singleOutcome {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (A : R) (hA_pos : 0 ≤ A) (hA_le_one : A ≤ 1) :

              A one-outcome submeasurement associated to a single positive operator bounded by the identity.

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                @[simp]
                theorem MIPRE.LIDT.Co.SubMeas.singleOutcome_outcome {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (A : R) (hA_pos : 0 ≤ A) (hA_le_one : A ≤ 1) (u : Unit) :
                (singleOutcome A hA_pos hA_le_one).outcome u = A

                The single outcome operator of singleOutcome A is A.

                @[simp]
                theorem MIPRE.LIDT.Co.SubMeas.singleOutcome_total {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (A : R) (hA_pos : 0 ≤ A) (hA_le_one : A ≤ 1) :
                (singleOutcome A hA_pos hA_le_one).total = A

                The total of singleOutcome A is A.

                theorem MIPRE.LIDT.Co.SubMeas.sum_eq_one_iff_total_eq_one {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (A : SubMeas α R) :
                ∑ a : α, A.outcome a = 1 ↔ A.total = 1

                A submeasurement is complete exactly when its outcome operators sum to 1.

                def MIPRE.LIDT.Co.SubMeas.toMeasurement {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (A : SubMeas α R) (hcomplete : A.total = 1) :

                Promote a complete submeasurement to a measurement.

                This is the explicit bridge from the paper's sub-measurement convention ∑ a, A_a ≤ I to the POVM convention ∑ a, A_a = I: callers must supply the completion proof rather than relying on a degenerate default.

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                  @[simp]
                  theorem MIPRE.LIDT.Co.SubMeas.toMeasurement_toSubMeas {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (A : SubMeas α R) (hcomplete : A.total = 1) :
                  (A.toMeasurement hcomplete).toSubMeas = A

                  Promoting a complete submeasurement and forgetting completeness gives it back.

                  @[simp]
                  theorem MIPRE.LIDT.Co.SubMeas.toMeasurement_outcome {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (A : SubMeas α R) (hcomplete : A.total = 1) (a : α) :
                  (A.toMeasurement hcomplete).outcome a = A.outcome a

                  Promotion to a measurement keeps the outcome operators.

                  theorem MIPRE.LIDT.Co.Measurement.sum_eq {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (M : Measurement α R) :
                  ∑ a : α, M.outcome a = 1

                  The outcome operators of a measurement sum to the identity.

                  theorem MIPRE.LIDT.Co.SubMeas.outcome_hermitian {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (A : SubMeas α R) (a : α) :
                  star (A.outcome a) = A.outcome a

                  Positive outcomes are self-adjoint.

                  theorem MIPRE.LIDT.Co.Measurement.outcome_hermitian {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (M : Measurement α R) (a : α) :
                  star (M.outcome a) = M.outcome a

                  Positive outcomes are self-adjoint.

                  theorem MIPRE.LIDT.Co.SubMeas.outcome_le_total {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (A : SubMeas α R) (a : α) :

                  Every submeasurement outcome is bounded by the total operator.

                  theorem MIPRE.LIDT.Co.Measurement.outcome_le_one {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (M : Measurement α R) (a : α) :
                  M.outcome a ≤ 1

                  Each POVM element is bounded by the identity: outcome a ≤ 1. Proof: outcome a = 1 - ∑_{b ≠ a} outcome b ≤ 1 since all terms are positive.

                  theorem MIPRE.LIDT.Co.SubMeas.outcome_le_one {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (A : SubMeas α R) (a : α) :
                  A.outcome a ≤ 1

                  Every submeasurement outcome is bounded by the identity.

                  theorem MIPRE.LIDT.Co.SubMeas.total_nonneg {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (A : SubMeas α R) :

                  The total operator of a submeasurement is positive.

                  theorem MIPRE.LIDT.Co.ProjSubMeas.outcome_hermitian {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (P : ProjSubMeas α R) (a : α) :
                  star (P.outcome a) = P.outcome a

                  Projective submeasurement outcomes are self-adjoint (positive by assumption).

                  theorem MIPRE.LIDT.Co.ProjMeas.outcome_hermitian {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (P : ProjMeas α R) (a : α) :
                  star (P.outcome a) = P.outcome a

                  Projective measurement outcomes are self-adjoint (inherited from Measurement.outcome_pos).

                  Projective submeasurements in a C*-algebra #

                  Each projective outcome is absorbed by the total operator.

                  The total operator of a projective submeasurement is itself a projector.

                  theorem MIPRE.LIDT.Co.ProjSubMeas.outcome_orthogonal {α : Type u_1} [Fintype α] {R : Type u_2} [CStarAlgebra R] [PartialOrder R] [StarOrderedRing R] (P : ProjSubMeas α R) (a b : α) (hab : a ≠ b) :
                  P.outcome a * P.outcome b = 0

                  Distinct outcomes of a projective submeasurement are orthogonal.

                  theorem MIPRE.LIDT.Co.ProjMeas.outcome_orthogonal {α : Type u_1} [Fintype α] {R : Type u_2} [CStarAlgebra R] [PartialOrder R] [StarOrderedRing R] (P : ProjMeas α R) (a b : α) (hab : a ≠ b) :
                  P.outcome a * P.outcome b = 0

                  Distinct outcomes of a projective measurement are orthogonal.

                  theorem MIPRE.LIDT.Co.ProjMeas.outcome_commute {α : Type u_1} [Fintype α] {R : Type u_2} [CStarAlgebra R] [PartialOrder R] [StarOrderedRing R] (P : ProjMeas α R) (a b : α) :
                  P.outcome a * P.outcome b = P.outcome b * P.outcome a

                  Any two outcomes of a ProjMeas commute.

                  Images under ⋆-homomorphisms #

                  The port's placement of a local family on a tensor factor: A.map S.L is the vendored SubMeas.liftLeft A, and A.map S.R the vendored SubMeas.liftRight A.

                  def MIPRE.LIDT.Co.SubMeas.map {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [Algebra ℂ R] [PartialOrder R] [StarOrderedRing R] {T : Type u_3} [Ring T] [StarRing T] [Algebra ℂ T] [PartialOrder T] [StarOrderedRing T] (f : R →⋆ₐ[ℂ] T) (A : SubMeas α R) :
                  SubMeas α T

                  The image of a submeasurement under a ⋆-algebra homomorphism.

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                    @[simp]
                    theorem MIPRE.LIDT.Co.SubMeas.map_outcome {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [Algebra ℂ R] [PartialOrder R] [StarOrderedRing R] {T : Type u_3} [Ring T] [StarRing T] [Algebra ℂ T] [PartialOrder T] [StarOrderedRing T] (f : R →⋆ₐ[ℂ] T) (A : SubMeas α R) (a : α) :
                    (map f A).outcome a = f (A.outcome a)

                    The outcome operators of the image are the images of the outcome operators.

                    @[simp]
                    theorem MIPRE.LIDT.Co.SubMeas.map_total {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [Algebra ℂ R] [PartialOrder R] [StarOrderedRing R] {T : Type u_3} [Ring T] [StarRing T] [Algebra ℂ T] [PartialOrder T] [StarOrderedRing T] (f : R →⋆ₐ[ℂ] T) (A : SubMeas α R) :
                    (map f A).total = f A.total

                    The total of the image is the image of the total.

                    def MIPRE.LIDT.Co.Measurement.map {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [Algebra ℂ R] [PartialOrder R] [StarOrderedRing R] {T : Type u_3} [Ring T] [StarRing T] [Algebra ℂ T] [PartialOrder T] [StarOrderedRing T] (f : R →⋆ₐ[ℂ] T) (M : Measurement α R) :

                    The image of a measurement under a ⋆-algebra homomorphism.

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                      @[simp]

                      The image of a measurement, as a submeasurement, is the image of its submeasurement.

                      @[simp]
                      theorem MIPRE.LIDT.Co.Measurement.map_outcome {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [Algebra ℂ R] [PartialOrder R] [StarOrderedRing R] {T : Type u_3} [Ring T] [StarRing T] [Algebra ℂ T] [PartialOrder T] [StarOrderedRing T] (f : R →⋆ₐ[ℂ] T) (M : Measurement α R) (a : α) :
                      (map f M).outcome a = f (M.outcome a)

                      The outcome operators of the image measurement are the images of the outcome operators.

                      def MIPRE.LIDT.Co.ProjSubMeas.map {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [Algebra ℂ R] [PartialOrder R] [StarOrderedRing R] {T : Type u_3} [Ring T] [StarRing T] [Algebra ℂ T] [PartialOrder T] [StarOrderedRing T] (f : R →⋆ₐ[ℂ] T) (P : ProjSubMeas α R) :

                      The image of a projective submeasurement under a ⋆-algebra homomorphism.

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                        @[simp]

                        The image of a projective submeasurement, as a submeasurement, is the image of its submeasurement.

                        def MIPRE.LIDT.Co.ProjMeas.map {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [Algebra ℂ R] [PartialOrder R] [StarOrderedRing R] {T : Type u_3} [Ring T] [StarRing T] [Algebra ℂ T] [PartialOrder T] [StarOrderedRing T] (f : R →⋆ₐ[ℂ] T) (P : ProjMeas α R) :

                        The image of a projective measurement under a ⋆-algebra homomorphism.

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                          @[simp]

                          The image of a projective measurement, as a measurement, is the image of its measurement.

                          Bridges to MIPRE.POVMIn and MIPRE.IsPVMIn #

                          def MIPRE.LIDT.Co.Measurement.ofPOVMIn {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (P : POVMIn α R) :

                          A positive operator valued measure of the repository as a measurement.

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                            @[simp]
                            theorem MIPRE.LIDT.Co.Measurement.ofPOVMIn_outcome {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] (P : POVMIn α R) (a : α) :
                            (ofPOVMIn P).outcome a = P.op a

                            The outcome operators of ofPOVMIn P are the operators of P.

                            def MIPRE.LIDT.Co.Measurement.toPOVMIn {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (M : Measurement α R) :
                            POVMIn α R

                            A measurement as a positive operator valued measure of the repository (MIPRE/Foundations/Measurement.lean).

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                              @[simp]
                              theorem MIPRE.LIDT.Co.Measurement.toPOVMIn_op {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (M : Measurement α R) (a : α) :

                              The operators of toPOVMIn M are the outcome operators of M.

                              @[simp]

                              ofPOVMIn is a left inverse of toPOVMIn.

                              @[simp]

                              toPOVMIn is a left inverse of ofPOVMIn.

                              def MIPRE.LIDT.Co.ProjMeas.ofIsPVMIn {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (P : α → R) (h : IsPVMIn P) :

                              A family of self-adjoint idempotents summing to one, mutually orthogonal, as a projective measurement.

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                                @[simp]
                                theorem MIPRE.LIDT.Co.ProjMeas.ofIsPVMIn_outcome {α : Type u_1} [Fintype α] {R : Type u_2} [Ring R] [StarRing R] [PartialOrder R] [StarOrderedRing R] (P : α → R) (h : IsPVMIn P) (a : α) :
                                (ofIsPVMIn P h).outcome a = P a

                                The outcome operators of ofIsPVMIn P h are the P a.

                                A projective measurement is a projective measurement of the repository (MIPRE/Foundations/Measurement.lean): orthogonality is ProjSubMeas.outcome_orthogonal.