ASPBE Lean Blueprint

10.60. QuantumBlockEncoding/StoredHermiteChildGeometry.lean🔗

24 explicit public declarations, in source order.

Definition10.60.1
uses 0used by 0L∃∀N

Plain-English reading. This record groups the data and proof fields needed for “flags”. A proposition-valued field is a requirement until a constructor supplies it.

Formal status. Data contract in the default import surface; proposition-valued fields are obligations, not automatically established facts.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. structure.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:19. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Definition10.60.11 definition
  • complete
    structure QuantumBlockEncoding.StoredHermiteChildGeometry.Flags : Type
    structure QuantumBlockEncoding.StoredHermiteChildGeometry.Flags :
      Type

    Fields

    full : Bool
    isPartial : Bool
Definition10.60.2
uses 0used by 0L∃∀N

Plain-English reading. This definition gives the library's named construction or computation for “flags”. Four actual integer comparisons; 'last' is the excluded integer endpoint.

Formal status. Compiled declaration in the default ASPBE import surface; its kind and displayed Lean type determine how it may be used.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. Four actual integer comparisons; 'last' is the excluded integer endpoint.

Declaration kind. def.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:24. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Definition10.60.21 definition
  • def QuantumBlockEncoding.StoredHermiteChildGeometry.flags
      (lower upper first last : ) :
      QuantumBlockEncoding.StoredGivens.Run
        QuantumBlockEncoding.StoredHermiteChildGeometry.Flags
    def QuantumBlockEncoding.StoredHermiteChildGeometry.flags
      (lower upper first last : ) :
      QuantumBlockEncoding.StoredGivens.Run
        QuantumBlockEncoding.StoredHermiteChildGeometry.Flags
    Four actual integer comparisons; `last` is the excluded integer endpoint. 
Theorem10.60.3
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “flags full”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:32. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.31 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.flags_full
      (lower upper first size : ) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.flags lower upper
              first (first + size)).value.full =
        decide
          (QuantumBlockEncoding.HermiteBoundaryInjection.Full lower upper
            first size)
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.flags_full
      (lower upper first size : ) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.flags
              lower upper first
              (first + size)).value.full =
        decide
          (QuantumBlockEncoding.HermiteBoundaryInjection.Full
            lower upper first size)
Theorem10.60.4
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “flags partial”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:36. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.41 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.flags_partial
      (lower upper first size : ) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.flags lower upper
              first (first + size)).value.isPartial =
        decide
          (QuantumBlockEncoding.HermiteBoundaryInjection.Partial lower upper
            first size)
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.flags_partial
      (lower upper first size : ) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.flags
              lower upper first
              (first +
                size)).value.isPartial =
        decide
          (QuantumBlockEncoding.HermiteBoundaryInjection.Partial
            lower upper first size)
Theorem10.60.5
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “flags cost”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:42. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.51 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.flags_cost
      (lower upper first last : )
      (op : QuantumBlockEncoding.StoredGivens.Op) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.flags lower upper
              first last).cost
          op =
        4 *
            QuantumBlockEncoding.StoredGivens.tick
              QuantumBlockEncoding.StoredGivens.Op.compare op +
          2 *
            QuantumBlockEncoding.StoredGivens.tick
              QuantumBlockEncoding.StoredGivens.Op.write op
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.flags_cost
      (lower upper first last : )
      (op :
        QuantumBlockEncoding.StoredGivens.Op) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.flags
              lower upper first last).cost
          op =
        4 *
            QuantumBlockEncoding.StoredGivens.tick
              QuantumBlockEncoding.StoredGivens.Op.compare
              op +
          2 *
            QuantumBlockEncoding.StoredGivens.tick
              QuantumBlockEncoding.StoredGivens.Op.write
              op
Definition10.60.6
uses 0used by 0L∃∀N

Plain-English reading. This record groups the data and proof fields needed for “child”. A proposition-valued field is a requirement until a constructor supplies it.

Formal status. Data contract in the default import surface; proposition-valued fields are obligations, not automatically established facts.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. structure.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:47. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Definition10.60.61 definition
  • complete
    structure QuantumBlockEncoding.StoredHermiteChildGeometry.Child : Type
    structure QuantumBlockEncoding.StoredHermiteChildGeometry.Child :
      Type

    Fields

    first : 
    lower : 
    upper : 
    leftFull : Bool
    leftPartial : Bool
    middleFull : Bool
    middlePartial : Bool
Definition10.60.7
uses 0used by 0L∃∀N

Plain-English reading. This record groups the data and proof fields needed for “child run”. A proposition-valued field is a requirement until a constructor supplies it.

Formal status. Data contract in the default import surface; proposition-valued fields are obligations, not automatically established facts.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. structure.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:56. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Definition10.60.71 definition
  • complete
    structure QuantumBlockEncoding.StoredHermiteChildGeometry.ChildRun (α : Type) :
      Type
    structure QuantumBlockEncoding.StoredHermiteChildGeometry.ChildRun
      (α : Type) : Type

    Fields

    run : QuantumBlockEncoding.StoredGivens.Run α
    integerAdditions : 
Definition10.60.8
uses 0used by 0L∃∀N

Plain-English reading. This definition gives the library's named construction or computation for “child”.

Formal status. Compiled declaration in the default ASPBE import surface; its kind and displayed Lean type determine how it may be used.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. def.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:60. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Definition10.60.81 definition
  • def QuantumBlockEncoding.StoredHermiteChildGeometry.child
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      QuantumBlockEncoding.StoredHermiteChildGeometry.ChildRun
        QuantumBlockEncoding.StoredHermiteChildGeometry.Child
    def QuantumBlockEncoding.StoredHermiteChildGeometry.child
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      QuantumBlockEncoding.StoredHermiteChildGeometry.ChildRun
        QuantumBlockEncoding.StoredHermiteChildGeometry.Child
Theorem10.60.9
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “child first”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:81. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.91 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_first
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
                span cut midpoint bit).run.value.first =
        parent.first + if bit = true then span else 0
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_first
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child
                parent level span cut midpoint
                bit).run.value.first =
        parent.first +
          if bit = true then span else 0
Theorem10.60.10
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “child lower”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:87. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.101 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_lower
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
                span cut midpoint bit).run.value.lower =
        parent.lower + (if bit = true then 1 else 0) * level.width
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_lower
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child
                parent level span cut midpoint
                bit).run.value.lower =
        parent.lower +
          (if bit = true then 1 else 0) *
            level.width
Theorem10.60.11
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “child upper”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:93. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.111 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_upper
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
                span cut midpoint bit).run.value.upper =
        (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
                  span cut midpoint bit).run.value.lower +
          level.width
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_upper
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child
                parent level span cut midpoint
                bit).run.value.upper =
        (QuantumBlockEncoding.StoredHermiteChildGeometry.child
                  parent level span cut
                  midpoint
                  bit).run.value.lower +
          level.width
Theorem10.60.12
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “child flags”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:98. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.121 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_flags
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      have c :=
        (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
              span cut midpoint bit).run.value;
      c.leftFull =
          decide
            (QuantumBlockEncoding.HermiteBoundaryInjection.Full 0 cut
              c.first span) 
        c.leftPartial =
            decide
              (QuantumBlockEncoding.HermiteBoundaryInjection.Partial 0 cut
                c.first span) 
          c.middleFull =
              decide
                (QuantumBlockEncoding.HermiteBoundaryInjection.Full cut
                  midpoint c.first span) 
            c.middlePartial =
              decide
                (QuantumBlockEncoding.HermiteBoundaryInjection.Partial cut
                  midpoint c.first span)
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_flags
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      have c :=
        (QuantumBlockEncoding.StoredHermiteChildGeometry.child
              parent level span cut midpoint
              bit).run.value;
      c.leftFull =
          decide
            (QuantumBlockEncoding.HermiteBoundaryInjection.Full
              0 cut c.first span) 
        c.leftPartial =
            decide
              (QuantumBlockEncoding.HermiteBoundaryInjection.Partial
                0 cut c.first span) 
          c.middleFull =
              decide
                (QuantumBlockEncoding.HermiteBoundaryInjection.Full
                  cut midpoint c.first span) 
            c.middlePartial =
              decide
                (QuantumBlockEncoding.HermiteBoundaryInjection.Partial
                  cut midpoint c.first span)
Theorem10.60.13
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “child cost”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:109. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.131 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_cost
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool)
      (op : QuantumBlockEncoding.StoredGivens.Op) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
                span cut midpoint bit).run.cost
          op =
        3 *
                QuantumBlockEncoding.StoredGivens.tick
                  QuantumBlockEncoding.StoredGivens.Op.field op +
              9 *
                QuantumBlockEncoding.StoredGivens.tick
                  QuantumBlockEncoding.StoredGivens.Op.compare op +
            7 *
              QuantumBlockEncoding.StoredGivens.tick
                QuantumBlockEncoding.StoredGivens.Op.read op +
          11 *
            QuantumBlockEncoding.StoredGivens.tick
              QuantumBlockEncoding.StoredGivens.Op.write op
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_cost
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool)
      (op :
        QuantumBlockEncoding.StoredGivens.Op) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child
                parent level span cut midpoint
                bit).run.cost
          op =
        3 *
                QuantumBlockEncoding.StoredGivens.tick
                  QuantumBlockEncoding.StoredGivens.Op.field
                  op +
              9 *
                QuantumBlockEncoding.StoredGivens.tick
                  QuantumBlockEncoding.StoredGivens.Op.compare
                  op +
            7 *
              QuantumBlockEncoding.StoredGivens.tick
                QuantumBlockEncoding.StoredGivens.Op.read
                op +
          11 *
            QuantumBlockEncoding.StoredGivens.tick
              QuantumBlockEncoding.StoredGivens.Op.write
              op
Theorem10.60.14
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “child integer additions”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:117. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.141 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_integerAdditions
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
            span cut midpoint bit).integerAdditions =
        2
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_integerAdditions
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child
            parent level span cut midpoint
            bit).integerAdditions =
        2
Theorem10.60.15
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “child refines”; the hypotheses and conclusion in the code panel fix its exact scope. Value-only specification: all cached-data hypotheses are explicit.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. Value-only specification: all cached-data hypotheses are explicit.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:122. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.151 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_refines
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint n r : ) (origin grid : ) (bit : Bool)
      (hp :
        parent.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule cut
            (r + 1))
      (hl :
        parent.lower =
          QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint origin
            grid parent.first)
      (hw : level.width = grid * 2 ^ r) (hs : span = 2 ^ r)
      (hm : midpoint = 2 ^ n) :
      have c :=
        (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
              span cut midpoint bit).run.value;
      c.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
            (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
              cut)
            r bit 
        c.lower =
            QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint origin
              grid
              (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                  cut)
                r bit) 
          c.upper =
              QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint
                origin grid
                (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                    (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                      cut)
                    r bit +
                  2 ^ r) 
            c.leftFull =
                decide
                  (QuantumBlockEncoding.HermiteBoundaryInjection.Full 0 cut
                    (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                      (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                        cut)
                      r bit)
                    (2 ^ r)) 
              c.leftPartial =
                  decide
                    (QuantumBlockEncoding.HermiteBoundaryInjection.Partial 0
                      cut
                      (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                        (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                          cut)
                        r bit)
                      (2 ^ r)) 
                c.middleFull =
                    decide
                      (QuantumBlockEncoding.HermiteBoundaryInjection.Full
                        cut (2 ^ n)
                        (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                          (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                            cut)
                          r bit)
                        (2 ^ r)) 
                  c.middlePartial =
                    decide
                      (QuantumBlockEncoding.HermiteBoundaryInjection.Partial
                        cut (2 ^ n)
                        (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                          (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                            cut)
                          r bit)
                        (2 ^ r))
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_refines
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint n r : )
      (origin grid : ) (bit : Bool)
      (hp :
        parent.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
            cut (r + 1))
      (hl :
        parent.lower =
          QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint
            origin grid parent.first)
      (hw : level.width = grid * 2 ^ r)
      (hs : span = 2 ^ r)
      (hm : midpoint = 2 ^ n) :
      have c :=
        (QuantumBlockEncoding.StoredHermiteChildGeometry.child
              parent level span cut midpoint
              bit).run.value;
      c.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
            (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
              cut)
            r bit 
        c.lower =
            QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint
              origin grid
              (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                  cut)
                r bit) 
          c.upper =
              QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint
                origin grid
                (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                    (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                      cut)
                    r bit +
                  2 ^ r) 
            c.leftFull =
                decide
                  (QuantumBlockEncoding.HermiteBoundaryInjection.Full
                    0 cut
                    (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                      (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                        cut)
                      r bit)
                    (2 ^ r)) 
              c.leftPartial =
                  decide
                    (QuantumBlockEncoding.HermiteBoundaryInjection.Partial
                      0 cut
                      (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                        (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                          cut)
                        r bit)
                      (2 ^ r)) 
                c.middleFull =
                    decide
                      (QuantumBlockEncoding.HermiteBoundaryInjection.Full
                        cut (2 ^ n)
                        (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                          (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                            cut)
                          r bit)
                        (2 ^ r)) 
                  c.middlePartial =
                    decide
                      (QuantumBlockEncoding.HermiteBoundaryInjection.Partial
                        cut (2 ^ n)
                        (QuantumBlockEncoding.HermiteBoundaryInjection.selectedChild
                          (QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
                            cut)
                          r bit)
                        (2 ^ r))
    Value-only specification: all cached-data hypotheses are explicit. 
Definition10.60.16
uses 0used by 0L∃∀N

Plain-English reading. This definition gives the library's named construction or computation for “children”. False/true children are computed once each, then stored in this order.

Formal status. Compiled declaration in the default ASPBE import surface; its kind and displayed Lean type determine how it may be used.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. False/true children are computed once each, then stored in this order.

Declaration kind. def.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:157. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Definition10.60.161 definition
  • def QuantumBlockEncoding.StoredHermiteChildGeometry.children
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) :
      QuantumBlockEncoding.StoredHermiteChildGeometry.ChildRun
        (Vector QuantumBlockEncoding.StoredHermiteChildGeometry.Child 2)
    def QuantumBlockEncoding.StoredHermiteChildGeometry.children
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) :
      QuantumBlockEncoding.StoredHermiteChildGeometry.ChildRun
        (Vector
          QuantumBlockEncoding.StoredHermiteChildGeometry.Child
          2)
    False/true children are computed once each, then stored in this order. 
Theorem10.60.17
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “children value”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:167. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.171 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_value
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.children parent level
                span cut midpoint).run.value[if bit = true then 1 else 0] =
        (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
              span cut midpoint bit).run.value
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_value
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (bit : Bool) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.children
                parent level span cut
                midpoint).run.value[if
              bit = true then 1
          else 0] =
        (QuantumBlockEncoding.StoredHermiteChildGeometry.child
              parent level span cut midpoint
              bit).run.value
Theorem10.60.18
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “children cost”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:173. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.181 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_cost
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) (op : QuantumBlockEncoding.StoredGivens.Op) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.children parent level
                span cut midpoint).run.cost
          op =
        6 *
                QuantumBlockEncoding.StoredGivens.tick
                  QuantumBlockEncoding.StoredGivens.Op.field op +
              20 *
                QuantumBlockEncoding.StoredGivens.tick
                  QuantumBlockEncoding.StoredGivens.Op.compare op +
            18 *
              QuantumBlockEncoding.StoredGivens.tick
                QuantumBlockEncoding.StoredGivens.Op.read op +
          26 *
            QuantumBlockEncoding.StoredGivens.tick
              QuantumBlockEncoding.StoredGivens.Op.write op
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_cost
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : )
      (op :
        QuantumBlockEncoding.StoredGivens.Op) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.children
                parent level span cut
                midpoint).run.cost
          op =
        6 *
                QuantumBlockEncoding.StoredGivens.tick
                  QuantumBlockEncoding.StoredGivens.Op.field
                  op +
              20 *
                QuantumBlockEncoding.StoredGivens.tick
                  QuantumBlockEncoding.StoredGivens.Op.compare
                  op +
            18 *
              QuantumBlockEncoding.StoredGivens.tick
                QuantumBlockEncoding.StoredGivens.Op.read
                op +
          26 *
            QuantumBlockEncoding.StoredGivens.tick
              QuantumBlockEncoding.StoredGivens.Op.write
              op
Theorem10.60.19
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “children integer additions”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:181. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.191 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_integerAdditions
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.children parent level
            span cut midpoint).integerAdditions =
        4
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_integerAdditions
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.children
            parent level span cut
            midpoint).integerAdditions =
        4
Theorem10.60.20
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “children total cost”; the hypotheses and conclusion in the code panel fix its exact scope. Fixed charged work for both children; integer additions remain separate.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. Fixed charged work for both children; integer additions remain separate.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:186. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.201 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_total_cost
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) :
       op,
          (QuantumBlockEncoding.StoredHermiteChildGeometry.children parent
                  level span cut midpoint).run.cost
            op =
        70
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_total_cost
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint : ) :
       op,
          (QuantumBlockEncoding.StoredHermiteChildGeometry.children
                  parent level span cut
                  midpoint).run.cost
            op =
        70
    Fixed charged work for both children; integer additions remain separate. 
Definition10.60.21
uses 0used by 0L∃∀N

Plain-English reading. This definition gives the library's named construction or computation for “refines”.

Formal status. Compiled declaration in the default ASPBE import surface; its kind and displayed Lean type determine how it may be used.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. def.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:194. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Definition10.60.211 definition
  • def QuantumBlockEncoding.StoredHermiteChildGeometry.Refines
      (c : QuantumBlockEncoding.StoredHermiteChildGeometry.Child)
      (cut n r : ) (origin grid : ) (bit : Bool) : Prop
    def QuantumBlockEncoding.StoredHermiteChildGeometry.Refines
      (c :
        QuantumBlockEncoding.StoredHermiteChildGeometry.Child)
      (cut n r : ) (origin grid : )
      (bit : Bool) : Prop
Theorem10.60.22
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “children refines”; the hypotheses and conclusion in the code panel fix its exact scope.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. The source declaration has no docstring. The reader cue above is generated from its kind and name and does not replace the Lean signature.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:203. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.221 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_refines
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint n r : ) (origin grid : ) (bit : Bool)
      (hp :
        parent.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule cut
            (r + 1))
      (hl :
        parent.lower =
          QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint origin
            grid parent.first)
      (hw : level.width = grid * 2 ^ r) (hs : span = 2 ^ r)
      (hm : midpoint = 2 ^ n) :
      QuantumBlockEncoding.StoredHermiteChildGeometry.Refines
        (QuantumBlockEncoding.StoredHermiteChildGeometry.children parent
                level span cut
                midpoint).run.value[if bit = true then 1 else 0]
        cut n r origin grid bit
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_refines
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint n r : )
      (origin grid : ) (bit : Bool)
      (hp :
        parent.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
            cut (r + 1))
      (hl :
        parent.lower =
          QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint
            origin grid parent.first)
      (hw : level.width = grid * 2 ^ r)
      (hs : span = 2 ^ r)
      (hm : midpoint = 2 ^ n) :
      QuantumBlockEncoding.StoredHermiteChildGeometry.Refines
        (QuantumBlockEncoding.StoredHermiteChildGeometry.children
                parent level span cut
                midpoint).run.value[if
              bit = true then 1
          else 0]
        cut n r origin grid bit
Theorem10.60.23
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “children certified”; the hypotheses and conclusion in the code panel fix its exact scope. Refinement and charged work belong to the same pair-producing run.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. Refinement and charged work belong to the same pair-producing run.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:215. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.231 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_certified
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint n r : ) (origin grid : )
      (hp :
        parent.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule cut
            (r + 1))
      (hl :
        parent.lower =
          QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint origin
            grid parent.first)
      (hw : level.width = grid * 2 ^ r) (hs : span = 2 ^ r)
      (hm : midpoint = 2 ^ n) :
      have result :=
        QuantumBlockEncoding.StoredHermiteChildGeometry.children parent
          level span cut midpoint;
      (∀ (bit : Bool),
          QuantumBlockEncoding.StoredHermiteChildGeometry.Refines
            result.run.value[if bit = true then 1 else 0] cut n r origin
            grid bit) 
         op, result.run.cost op = 70  result.integerAdditions = 4
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.children_certified
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint n r : )
      (origin grid : )
      (hp :
        parent.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
            cut (r + 1))
      (hl :
        parent.lower =
          QuantumBlockEncoding.HermiteBoundaryInjection.affinePoint
            origin grid parent.first)
      (hw : level.width = grid * 2 ^ r)
      (hs : span = 2 ^ r)
      (hm : midpoint = 2 ^ n) :
      have result :=
        QuantumBlockEncoding.StoredHermiteChildGeometry.children
          parent level span cut midpoint;
      (∀ (bit : Bool),
          QuantumBlockEncoding.StoredHermiteChildGeometry.Refines
            result.run.value[if
                  bit = true then 1
              else 0]
            cut n r origin grid bit) 
         op, result.run.cost op = 70 
          result.integerAdditions = 4
    Refinement and charged work belong to the same pair-producing run. 
Theorem10.60.24
uses 0used by 0L∃∀N

Plain-English reading. Lean checks the proposition indexed as “child index word bound”; the hypotheses and conclusion in the code panel fix its exact scope. With legal source indices, every generated endpoint fits in n+2 bits.

Formal status. Compiled theorem in the default ASPBE import surface; the displayed Lean signature is the authoritative claim.

Why it is in this chapter. Paper-facing backend models, source-specific Hermite constructions, and concrete State Preparation / Robin example artifacts.

Technical source note. With legal source indices, every generated endpoint fits in n+2 bits. This states a word-size requirement, not the cost of implementing word arithmetic.

Declaration kind. theorem.

Source: QuantumBlockEncoding/StoredHermiteChildGeometry.lean:230. A commit-pinned external link is added by the publication build when the source exists at the published ref.

Lean code for Theorem10.60.241 theorem
  • theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_index_word_bound
      (parent : QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level : QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint n r : ) (bit : Bool)
      (hp :
        parent.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule cut
            (r + 1))
      (hs : span = 2 ^ r) (hc : cut  2 ^ n) (hr : r  n) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child parent level
                  span cut midpoint bit).run.value.first +
          span <
        2 ^ (n + 2)
    theorem QuantumBlockEncoding.StoredHermiteChildGeometry.child_index_word_bound
      (parent :
        QuantumBlockEncoding.StoredBinaryCoordinates.Point)
      (level :
        QuantumBlockEncoding.StoredHermiteGeometry.TailLevel)
      (span cut midpoint n r : ) (bit : Bool)
      (hp :
        parent.first =
          QuantumBlockEncoding.HermiteBoundaryInjection.boundarySchedule
            cut (r + 1))
      (hs : span = 2 ^ r) (hc : cut  2 ^ n)
      (hr : r  n) :
      (QuantumBlockEncoding.StoredHermiteChildGeometry.child
                  parent level span cut
                  midpoint
                  bit).run.value.first +
          span <
        2 ^ (n + 2)
    With legal source indices, every generated endpoint fits in n+2 bits.
    This states a word-size requirement, not the cost of implementing word arithmetic.