computo ergo sum

2026-10-09 · chapter Yang–Mills and the mass gapPart 10 Towards a proof of the mass gap — building the first step of the staircaseLean, #print axioms, encoding of statements · Kiichi, Shiori and Rin

The whole book Contents and reading orders
  1. Part 0 Entrance — how to read this book
  2. 0-01 How to read this book
  3. 0-02 One picture
  4. 0-03 Reading the problem statement word by word
  5. 0-04 Four dimensions in mathematics and four dimensions in physics
  6. Part 1 Mathematical preparation
  7. 1-01 Vector spaces and linear maps
  8. 1-02 What a group is
  9. 1-03 Lie groups and Lie algebras
  10. 1-04 SU(2) and SU(3)
  11. 1-05 Manifolds and tangent spaces
  12. 1-06 Differential forms and the exterior derivative
  13. 1-07 Vector bundles and connections
  14. 1-08 Probability and measure
  15. 1-09 Probability in infinite dimensions
  16. 1-10 Hilbert spaces and self-adjoint operators
  17. 1-11 Fourier analysis and distributions
  18. 1-12 Detour: what happens only in four dimensions
  19. Part 2 Physical preparation
  20. 2-01 Lagrangians and the action
  21. 2-02 The idea of a field
  22. 2-03 Electromagnetism is a gauge theory
  23. 2-04 Special relativity and spacetime
  24. 2-05 The bones of quantum mechanics
  25. 2-06 The harmonic oscillator and creation and annihilation
  26. 2-07 The idea of the path integral
  27. 2-08 Statistical mechanics and phase transitions
  28. 2-09 Detour: the gap and the correlation length in the Ising model
  29. 2-10 The relaxation time and the dynamical exponent z
  30. Part 3 Yang–Mills theory (classical)
  31. 3-01 The gauge principle
  32. 3-02 Non-abelian gauge fields
  33. 3-03 The action and the equations
  34. 3-04 Gauge theory as geometry
  35. 3-05 Instantons and topology
  36. 3-06 Detour: Donaldson and exotic R⁴
  37. 3-07 Yang–Mills inside the Standard Model
  38. Part 4 Quantisation
  39. 4-01 Canonical quantisation and the Hamiltonian
  40. 4-02 The path integral and Euclideanisation
  41. 4-03 Perturbation theory and Feynman diagrams
  42. 4-04 Divergences and renormalisation
  43. 4-05 The algebra of divergences
  44. 4-06 Asymptotic freedom
  45. 4-07 Dimensional transmutation and Λ
  46. 4-08 Gauge fixing and Faddeev–Popov
  47. 4-09 The axioms of quantum field theory
  48. 4-10 The Osterwalder–Schrader axioms and reconstruction
  49. 4-11 The definition of the mass gap
  50. 4-12 Detour: the perturbation series diverges
  51. Part 5 Lattice gauge theory
  52. 5-01 Wilson's lattice
  53. 5-02 The strong-coupling expansion
  54. 5-03 Reflection positivity and the transfer matrix
  55. 5-04 The infinite-volume limit and the cluster expansion
  56. 5-05 Weak coupling and the continuum limit
  57. 5-06 How U(1) differs from the non-abelian case
  58. 5-07 The Monte Carlo method
  59. 5-08 Measuring glueballs and the string tension
  60. 5-09 What to hold fixed when taking the limit
  61. 5-10 Lattice gauge theory with finite groups
  62. 5-11 Detour: Bakry–Émery and one-link integration
  63. Part 6 Constructive field theory
  64. 6-01 What constructive field theory is
  65. 6-02 Solvability in two dimensions and the Yang–Mills measure
  66. 6-03 Constructing scalar fields
  67. 6-04 The cluster expansion
  68. 6-05 The sequence of renormalisation group steps
  69. 6-06 Ultraviolet stability of three-dimensional Yang–Mills
  70. 6-07 Four dimensions
  71. 6-08 Triviality of φ⁴ in four dimensions
  72. 6-09 Stochastic quantisation and regularity structures
  73. 6-10 Where four dimensions stops
  74. 6-11 Obstacles other than divergence
  75. 6-12 Detour: "if 1/0 is given a symbol"
  76. Part 7 From the side of physics
  77. 7-01 How physics sees it
  78. 7-02 Mechanisms of confinement
  79. 7-03 The string picture
  80. 7-04 Large N
  81. 7-05 String theory and extra dimensions
  82. 7-06 How extra dimensions become invisible
  83. 7-07 Where gauge fields come from
  84. 7-08 Holography
  85. 7-09 The mass gap becomes geometry
  86. 7-10 Back to four dimensions
  87. 7-11 Supersymmetry and Seiberg–Witten
  88. 7-12 The sentence that plays the role of an equivalence principle
  89. 7-13 Where the way physics digs parts from mathematics
  90. Part 8 A dictionary of two languages — the physical and the mathematical view
  91. 8-01 How to read the dictionary
  92. 8-02 Dictionary A
  93. 8-03 Dictionary B
  94. 8-04 Dictionary C
  95. 8-05 The physical counterparts of our assumptions
  96. Part 9 Where things stand, and open tasks
  97. 9-01 How far the world has come
  98. 9-02 Where the two ways of digging part
  99. 9-03 Candidates for new concepts
  100. 9-04 The list of open tasks
  101. 9-05 Common misconceptions
  102. Part 10 Towards a proof of the mass gap — building the first step of the staircase
  103. 10-00 Entrance — the staircase, and the random walk, the ruler and the clock
  104. 10-01 The line of construction and Assumption H
  105. 10-02 Roads tried on the four-dimensional lattice, and walls
  106. 10-03 The four steps of the staircase — why we start from 0+1 dimensions
  107. 10-04 The path measure of the double well, and kinks
  108. 10-05 The statement of the first step — four conditions and Proposition 4.5
  109. 10-06 (H1) Local Poincaré within a phase
  110. 10-07 The map of (H2) — seven routes and the seam of the ring
  111. 10-08 What computer-assisted means — the conditions on the chain inside the window
  112. 10-09 The sector framework and the three strands of route 5
  113. 10-10 The list of detour plans — types of breakage
  114. 10-11 (H3)(H4) and the constant of the core
  115. 10-12 The integrated table and the dependency graph
  116. 10-13 Lean statements and the limits of machine checking
  117. 10-14 Reconciliation — the numbers of the record and the known numbers
  118. 10-15 What remains and its cost — the distance to a theorem
  119. 10-16 What is not claimed
  120. 10-17 Insights and small questions
  121. Part 11 Further considerations — beyond Assumption H, and other views
  122. 11-00 Further considerations — entrance
  123. 11-01 One form that obstructs H — a nearly conserved global quantity
  124. 11-02 Choosing the ruler and the coordinates again — the length at which conservation breaks
  125. 11-03 Two ways to repair H — the sector H and the local H
  126. 11-04 Which H the one-sided bridge needs
  127. 11-05 Making time continuous — the Hamiltonian lattice and the vacuum measure
  128. 11-06 Paying with rarity instead of convexity — renormalisation on groups and log-Sobolev
  129. 11-07 Because it is four dimensions — the dimensionless coupling and topology
  130. 11-08 Questions, and what is not claimed
  131. 11-A1 Table of notation for Part 11
  132. Appendices
  133. A-01 Table of notation
  134. A-02 Glossary
  135. A-03 Guide to the literature
  136. A-04 Lean and machine checking
  137. A-05 How this book was made
  138. A-06 Index of assumptions

Lean statements and the limits of machine checking

What this chapter shows — We confirm, with the list of bundles of the first step, the convention that what machine checking (Lean) guarantees is only that "the conclusion follows from the propositions as written (the list of assumptions)", and that it guarantees neither that the assumptions are true nor that the real numbers inside Lean represent physical quantities. We look, through examples with their sources withheld, at two types that cannot be detected even when #print axioms stays within the three standard axioms (putting the conclusion into a definition, and a circle of dependence), and we give a procedure by which readers can inspect statements themselves.

Prerequisite chapters — A-04 Lean and machine checking (the meaning of the label "Lean"), 10-12 §03 (the dependency graph and the rule of numbering), 10-08 §08 (assemblies that put the output of interval arithmetic as an assumption). For how to read Lean itself, see the Lean guide.

Said first — The level is [Y2]–[Y3]. §01–§02 and §06 can be read at [Y2]. This part places Assumption H at the axis of the study, and Lean is used as a tool to check the algebraic steps of its construction. This chapter shows neither the mass gap nor the continuum limit.

The order of this chapter
  1. What machine checking guarantees — the arrow from a list of assumptions to a conclusion (example: the composition of Proposition 4.5)
  2. The three axioms and #print axioms — the criterion of cleanness, why native_decide is not used
  3. The bundles of the first step — the number of theorems in each bundle, what algebra it is, how the assumptions are put (Table 1), the side of the four-dimensional lattice (Table 2)
  4. Assumptions next to theorem names — the discipline of reading, and the fact that the layer of interval arithmetic is outside Lean
  5. Four limits — the truth of the assumptions, the encoding of the objects, putting the conclusion into a definition, circles of dependence (Table 3)
  6. A procedure for readers to inspect for themselves — six questions
  7. Translating conventions — places where the same letter or the same name refers to different quantities (Table 4)
  8. How the bundles are divided — by article, paper and subject

01

What machine checking guarantees — the arrow from a list of assumptions to a conclusion

Lean is a system in which a mathematical statement is written as a type and its proof as a term of that type, and a small core (the kernel) mechanically checks that the proof matches the statement (Lean guide 01). The rows in this book labelled "Lean" refer to theorems that have passed that check. The label guarantees only one thing.

The convention of this book

What is guaranteed in a row labelled "Lean" is that if all the assumptions written in the statement of the theorem hold, then the conclusion written there holds. It is not guaranteed that the assumptions hold, that the symbols in the statement represent the quantities of the text, or that the statement means the same as the claim in the text.

As an example, we copy the statement of the theorem for the composition of Proposition 4.5 (10-05 §04 Step 3).

theorem H3_H4_compose (CP Cbox n ca K4 C ξ D hbar S0 : ℝ) (hn : 0 < n) (hca : ca < 1)
    (hh : 0 < hbar) (hS : 0 < S0) (hD : D = hbar / S0)
    (hH3 : CP ≤ (1 + 1 / n) * Cbox / (1 - ca)) (hH4 : Cbox ≤ K4 * (C * ξ) ^ 2 / D) :
    CP ≤ (1 + 1 / n) * K4 * C ^ 2 / (1 - ca) * (ξ ^ 2 * S0 / hbar)

How to read it. Everything in the brackets of the first line is a real number (ℝ); CP and ξ are just real numbers with names. hH3 takes the conclusion of Proposition H3, CP≤(1+1/n)Cbox/(1−calt)C_P\le(1+1/n)C_{\rm box}/(1-c_{\rm alt}), and hH4 the conclusion of Proposition H4, Cbox≤K4(Cξ)2/DC_{\rm box}\le K_4(C\xi)^2/D, as assumptions. What the theorem checked is the algebra by which (13) CP≤Kξ2S0/ℏC_P\le K\xi^2S_0/\hbar follows from these two and D=ℏ/S0D=\hbar/S_0. That CP is the Poincaré constant of the path measure at T=∞T=\infty, and that the conclusions of Propositions H3 and H4 actually hold (that is, conditions (H1)–(H4) and the premise rows), are outside Lean.

This character of "only the arrow" is not a weakness but a premise of how it is used. Many of the "Proved here" nodes in the dependency graph (10-12 §03) are algebra that takes assumption rows as input, and Lean checks that this algebra has no copying errors or sign errors. Because what enters as an assumption is named in the statement, it can be cross-checked against the list of assumption rows (the integrated table).

02

The three axioms and #print axioms

On top of the type theory of Lean's kernel, the standard toolkit adds three axioms: propositional extensionality propext (equivalent propositions are equal), soundness of quotients Quot.sound (equivalent elements are equal in the quotient), and choice Classical.choice (extracting an element from a proof of existence). Which axioms a theorem depends on is listed by the command #print axioms theorem_name.

In the bundles of this book, we put #print axioms for the main theorems at the end of each file, and our criterion of cleanness is that every line of its output is a subset of the three axioms. Using sorry, which skips a proof, adds sorryAx to the list, and declaring an axiom oneself adds its name, so this criterion is a mechanical confirmation that "the proof has no hole and no arbitrary axiom has been added". In every bundle of Table 1 (the "copy of the axiom output" column of Table 1; including the copies retaken on a second machine on 2026-10-09), we reread that there is not a single axiom name other than the three. Some theorems do not use Classical.choice among the three (for example, tb_range uses only propext and Quot.sound).

Detour native_decide: why it is not used

decide checks a proposition decided by finite case analysis by computation inside the kernel. native_decide translates the same computation into a Lean program, runs it as machine code, and trusts the answer. It is fast, but in exchange the range of trust widens from the kernel to the translator and the execution environment, and that trust appears in the list as an additional axiom (depending on the version, an axiom with a different name appears for each declaration). In the bundles of this book we do not use native_decide, and we put the criterion of cleanness as "every line of the list is a subset of the three axioms". Looking for the presence or absence of a particular axiom name would miss things when the naming changes between versions.

03

The bundles of the first step — what algebra was checked

The Lean theorems of the first step are divided into files (bundles) by subject. Table 1 lists the main bundles in the order of the chapters that cite them in the text. "Number of theorems" is the number of theorem / lemma declarations in the file, and the column "Representative theorem" gives the theorem name with that theorem's assumptions in the same column.

Table 1 The main bundles of the first step (the number of theorems is the number of declarations. Copy of the axiom output: ○ = the output of #print axioms at the end remains separately, and we reread that every line is a subset of the three axioms. Includes the copies retaken on a second machine on 2026-10-09)
BundleNumber of theoremsWhat algebraRepresentative theorem (assumptions)ChapterCopy of the axiom output
LatticeGaugeOneScale12H↑, H↓ and the rereading of mass (the equality version)hup_is_gap_positivity (0<m0\lt m, CP=1/m2C_P=1/m^2, CP≤Kξ2C_P\le K\xi^2)10-01○
LatticeGaugeHupBridge18The one-sided bridge, the lower half of the power, negative controlshup_is_gap_positivity_of_lower (0<mlat0\lt m_{\rm lat}, κ/mlat2≤CP\kappa/m_{\rm lat}^2\le C_P, CP≤Kξ2C_P\le K\xi^2), first_power_does_not_bridge (negative control)10-01○
LatticeGaugeDoubleWellTestbed7The skeleton of the finite sum of Proposition Llocal_rayleigh_ratio_le_one (0<m0\lt m, ak≥ma_k\ge m, ck≥0c_k\ge0, ∑ckak>0\sum c_ka_k\gt0)10-04○
LatticeGaugeTwoScalePoincare8Splitting of the variance, curvature of the convex core, values of the reduced two-state model, the band ratio of Glaubersplit_poincare_le (the splitting formula, two local Poincaré inequalities, the mean difference, additivity of forms, non-negative constants)10-04, 10-05○
LatticeGaugeDoubleWellKramers10From the bracketing of the ratio to the power form of Hpower_H_of_kink_ratio (0<K,s,δ0\lt K,s,\delta, 1≤R≤K/ℏ1\le R\le K/\hbar, s/ℏ≤ln⁡ξs/\hbar\le\ln\xi)10-04, 10-05○
LatticeGaugeH1Assembly17The algebra of rates of Proposition H1, the arithmetic of the margin at six nodes, Gershgorin on the ringH1_assembly (seven named ones: decomposition, the fine side, Helffer's criterion, the margin, 0<λ0\lt\lambda, (T4), the condition on rates)10-06○
LatticeGaugeCoarseSideUniform20Arithmetic of (T4), the two-sided form of MuckenhouptT4_paper_numeric (λc≥1.3×10−4\lambda_c\ge1.3\times10^{-4})10-06○
LatticeGaugeIntervalQfreeWindow150The linear-fractional map of Lemma TAU, the identity of the tilt, from covering to window, recomputation of the rate-limiting cellswin_qfree_window_le_of_interval_table (the table of interval-arithmetic output)10-08○
LatticeGaugeRingUnconditionedWindow20Assembly of the window for the outer chain of the ringunc_window_lt_one_of_table (the table of interval-arithmetic output)10-07, 10-08○
LatticeGaugeRingInnerChain22The ratio at the corner of the wall, SWS_W of the ringsw_inner_le (qin≤13/10q_{\rm in}\le13/10, qout≤0.998888530q_{\rm out}\le0.998888530)10-07○
LatticeGaugePartitionFramework14Sum over sectors, the Gibbs step, composition and the closing conditioncomp_close (X>0X\gt0, b,A≥0b,A\ge0, ℓ>0\ell\gt0, and the three inequalities of Barta, (Σ.3) and Bochner)10-09○
LatticeGaugeRemVProxy23Assembly of Proposition P5path5_conditional (with the remainder inequality, the proxy ratio, rarity and the arithmetic margin named)10-09○
LatticeGaugeDetourKills, …217, 16The arithmetic of "the line that killed it" for the detour plansLemmas for each type (10-10 Table 4)10-10○
LatticeGaugeBoxReduction23Lemma TP, even and odd boxes, averaging over shifts, positive and negative controlsbox_shift_average (the two-family inequality for each shift, Cbox≥0C_{\rm box}\ge0, the sum over overlaps ≤E\le\mathcal E)10-05, 10-11○
LatticeGaugeBoxGap18Proposition H4, the algebra of ckgc_{\rm kg}, the composition of H3 and H4H3_H4_compose (the statement of §01)10-05, 10-11○
LatticeGaugeCoreMixing, CoreMaxCorr, CoreThreeStage15, 20, 18The three stages of the core (Lemma BV, Proposition G, Lemma TB, combining the three stages)three_stage (the upper bound of each stage)10-11○
LatticeGaugeCoreActionGap15The vanishing of the local term, drawing the line at the endscloc_term_vanishes ((ΔScore), the reading of ξ\xi, ΔS∗<2S0\Delta S_*\lt2S_0)10-11○
LatticeGaugeGlobalLyapunov21The algebra of the Lyapunov criterion and the positive control of the one-dimensional Gaussiangauss1d_bbcg, gauss1d_equality (no assumptions)10-14○

The theorems of Table 1 are all inequalities and equalities on real numbers, finite sums and sequences. There is no theorem that has measures, operators or spaces of paths as types. The bundle of interval arithmetic (most of the 150 declarations of IntervalQfreeWindow) recomputes the formula for the upper bound of the last step cell by cell in rational numbers; there are many declarations, but the content is arithmetic. The index of all bundles is shared with Appendix A-04.

The side of the four-dimensional lattice. The theorems of the roads tried on the four-dimensional lattice (10-02 §07 Table 4), divided by the type of the object their statements speak about directly, are as in Table 2.

Table 2 The type of object and the character of the theorems on the side of the four-dimensional lattice (rows are theorems; the character symbols correspond to the classification of Table 4 of 10-02: R = reproof, A = arrangement, C = conditional, N = negative control, M = lattice theorem)
Type of objectNumber of theoremsExamples
Real numbers (and natural numbers) only23chain_band, drain_exponent
Sequences, real functions11S4_two_sided, conditional_scale_bound
Sums over finite sets and finite groups8intact_frac_le, meff_ge_of_corr
Operators on an inner-product space1tau_int_le
Lattice gauge fields (quaternions, Haar measure)3one_link, hess_gauge
Total46Counted by character (41 rows, counting two paired theorems as one row): R 11, A 15, C 7, N 5, M 3

There are three theorems that have lattice gauge fields as a type, and there is no theorem about expectations, correlations or gaps of the Wilson measure. As for the correspondence of characters, "reproof, arrangement, conditional, negative control, lattice theorem" of Table 4 of 10-02 correspond one to one to R, A, C, N, M of this table.

04

Assumptions next to theorem names

In the text and tables of this part, when we write a theorem name, we list the assumptions of that theorem in the same column (example: H1_assembly (assumptions: seven named ones)). If only the theorem name is written, it is read at the stage of summary as "settled in Lean", and conditional algebra swells into an unconditional result. In the integrated table (10-12), too, we wrote the theorem names and assumptions under each node of the graph.

In the computer-assisted rows, the Lean column splits into three layers (10-08 §08): (1) the algebraic core (monotonicity of the linear-fractional map, the identity of the tilt, the algebra from covering to window); (2) recomputation of the rate-limiting cells and of randomly chosen cells (not all cells); (3) the assembly that puts the table of interval-arithmetic output as an assumption and derives the conclusion for the whole window. Interval arithmetic itself (interval evaluation of the map of a step, quadrature, invariant sets, the conventions of rounding) is outside Lean, and its correctness rests on cross-checks and control tests (10-08 §07). The label of a theorem that puts the table as an assumption is read as "if the output of interval arithmetic is correct, the conclusion for the whole window is correct as algebra".

05

Four limits — what cannot be detected even within the three axioms

Even for a theorem that meets the criterion of cleanness (§02), the following four are not guaranteed. The first two restate the convention of §01; the last two are types in which the way the statement is written itself empties the conclusion.

(1) The truth of the assumptions. A theorem does not prove a single step of its assumptions. If hH4 of H3_H4_compose is false, the conclusion says nothing.

(2) The encoding of the objects. CP inside Lean is a real number with a name, and that it is the Poincaré constant of the path measure is a reading of the text. The check passes even if the same name refers to a different quantity in another bundle. For example, a theorem named measured_ratio exists in two bundles of the first step (CoreActionGap and HierarchicalLink), and they are statements about different quantities in different namespaces. A name is no guarantee of content.

(3) Putting the conclusion into a definition. If the desired property is written as it is inside a definition and that definition is taken as an assumption, the conclusion becomes a copy of the assumption, and the proof closes in one line. The following is pseudo-Lean showing only the type.

Putting the conclusion into a definition closes anything (pseudo-Lean, an example of the type)
def InSpectrum (E : ℝ) : Prop := E = 0 ∨ c ≤ E          -- write the desired property into the definition of "spectrum"
theorem gap (E : ℝ) (h : InSpectrum E) : E = 0 ∨ c ≤ E := h   -- just returns the assumption as it is
def massGap : ℝ := 1 / 2                                  -- put the value literally, and positivity closes too

All three lines pass the check, and the list from #print axioms is either empty or within the three axioms. Even so, "spectrum" is not tied to the spectrum of any operator, so there is no mathematical content. One document wrote one of the conjuncts of its main theorem in this type, and another as a number put literally. It is an example in which the theorem name contains "mass gap" and every check passes, yet the statement does not encode the object.

(4) A circle of dependence. Lean checks theorems one at a time. Even if theorem A takes the conclusion of B as an assumption and theorem B takes the conclusion of A as an assumption, both pass the check. Neither conclusion has been derived unconditionally, yet putting the two side by side makes it look "shown". The same holds when proofs are written in prose: one document put the final conclusion, that the gap is positive, as a premise of intermediate steps (clustering, uniqueness of the vacuum), "to be shown later". Drawn as a dependency graph, an edge goes back from a conclusion with a large number to a step with a small number, and the rule of numbering (10-12 §03) is broken.

Table 3 The four limits, and how this book guards against them
LimitVisible to the check?How this book guards against it
(1) The truth of the assumptionsNot visible (assumptions are arguments)Write the assumptions next to the theorem name (§04); count the assumption rows one by one in the integrated table (10-12 Table 1)
(2) The encoding of the objectsNot visible (it only gives names to real numbers)State the types of the Lean objects in the text ("real numbers, finite sums" of §03); translate conventions (§07); write, chapter by chapter, the correspondence between the quantities of the text and the symbols of the theorem statements
(3) Putting the conclusion into a definitionNot visible (stays within the three axioms)Copy the theorem statement into the text and read the definitions back (questions 3 and 4 of §06); give negative-control theorems (examples that collapse when an assumption is removed)
(4) A circle of dependenceNot visible (theorems are checked one at a time)The rule of numbering of the dependency graph; checking that the assumption rows do not contain the quantity of the conclusion (10-12 §03)

Negative-control theorems work as a guard against (3). For example, no_bound_when_c_one (if the two σ\sigma-algebras are the same, c=1c=1, the reduction to the box says nothing) and first_power_does_not_bridge (with the first power, the bridge cannot be built) show that the conclusion collapses when an assumption is removed, confirming that the assumption is not decoration but acts on the conclusion.

06

A procedure for readers to inspect for themselves — six questions

When reading a claim labelled Lean, ask the following six in order. They apply equally to the theorems of this book and to theorems of other documents.

  1. Cleanness. Is every line of the output of #print axioms a subset of propext, Classical.choice, Quot.sound? If you do not have the output at hand, it is "unconfirmed".
  2. The list of assumptions. Write out all the brackets before the colon in the theorem statement (the arguments whose types are propositions). Does a claim that the text calls "unconditional" still have propositional arguments?
  3. Trace back the definition of the conclusion. Open the definitions of the names that appear in the conclusion (such as InSpectrum), and see whether they contain the same sentence as the conclusion. Are the assumption and the conclusion unfoldings of the same proposition?
  4. The type of the object. Do the objects the claim should speak about (measures, operators, fields) appear as types in the theorem statement? If what appears is only real numbers, natural numbers and finite sums, the tie to the objects lies in the reading of the text.
  5. The direction of dependence. If the claim joins several theorems, arrange as numbered nodes which theorem takes the conclusion of which theorem as an assumption, and see whether the numbers of premises can be placed smaller than the numbers of conclusions. If not, it is a candidate for a circle.
  6. Negative control. Is an example given in which the conclusion collapses when one assumption is removed? If not, check for yourself whether that assumption acts on the conclusion.

Example. Applied to H3_H4_compose of §01: (1) a subset of the three axioms; (2) the propositional arguments are the seven hn, hca, hh, hS, hD, hH3, hH4; (3) the conclusion is an inequality of real numbers and no tracing back of definitions is needed; (4) the objects are all real numbers; (5) hH3 and hH4 are the conclusions of Propositions H3 and H4, and in the integrated graph [072], [075] and [104] are smaller than [105]; (6) no_bound_when_c_one shows that at calt=1c_{\rm alt}=1 the reduction to the box says nothing (hca is not decoration). The answer is "if Propositions H3 and H4 hold, the inequality of Proposition 4.5 follows as algebra", and no more.

07

Translating conventions — places where the same letter or the same name refers to different quantities

Lean theorems do not know the meaning of symbols, so the check passes even if the same letter refers to different quantities in different files. Table 4 translates the conventions inside the theorems into the notation table of this book (Appendix A-01) and writes discrepancies as discrepancies. The upper six rows are on the side of the four-dimensional lattice, the lower five on the side of the first step.

Table 4 Conventions inside Lean and the notation of this book
QuantityInside LeanThis bookDiscrepancy
β\betaOne-link integration eβ⟨u,M⟩e^{\beta\langle u,M\rangle}, ⟨u,M⟩=12Re tr(UM†)\langle u,M\rangle=\tfrac12{\rm Re\,tr}(UM^\dagger)β=2N/g2\beta=2N/g^2None (β=4/g2\beta=4/g^2 at N=2N=2). Against the convention of Shen–Zhu–Zhu, β=4βSZZ\beta=4\beta_{\rm SZZ}
tr and angleLink angle U=eiϑ⋅σU=e^{i\vartheta\cdot\sigma}Ta=σa/2T^a=\sigma^a/2, U=eiθaTaU=e^{i\theta^aT^a}θ=2ϑ\theta=2\vartheta, CP(θ)=4CP(ϑ)C_P^{(\theta)}=4C_P^{(\vartheta)}. A constant factor, so it does not affect the power
aaa of drain_exponentLattice spacingLean's aa is the reciprocal of the bookkeeping length, 1/ξRG1/\xi_{\rm RG}
η\etaThe static exponent, the exponent of susceptibility, the exponent of overlapηs\eta_s and ηdyn\eta_{\rm dyn} separated by subscriptsPresent (the same letter for three quantities)
κ\kappaThe one-loop slope, the coefficient of a model, the coefficient of the Casimir term, the contribution of faces sharing no edgeOnly the one-loop slope 11/(3π2)11/(3\pi^2)Present (the same letter for four quantities)
CPC_P (four dimensions)A real number with a nameThe Poincaré constant of Langevin. The normalisation is namedWith the normalisations of the field AA and the angle ϑ\vartheta, CP(A)=βCP(ϑ)C_P^{(A)}=\beta C_P^{(\vartheta)}
ℏ\hbar and ε\varepsilonhbar (a real number). The lattice spacing enters as a numberE(f)=(ℏ/ε)∑iE∣∂if∣2\mathcal E(f)=(\hbar/\varepsilon)\sum_i\mathbb E|\partial_if|^2, ε=12\varepsilon=\tfrac12None. The conversion between the readings at ε=0.25\varepsilon=0.25 and at ε=12\varepsilon=\tfrac12 is not written (10-14 §05)
The graduation of CPC_P for the coreCPC_P of the theorems of the stages of the core10-11 uses the convention of E\mathcal E, 10-09 the convention of ℏ∫∣∇g∣2\hbar\int|\nabla g|^2C(10-09)=C/ε=2CC^{(10\text{-}09)}=C/\varepsilon=2C (10-11 §05)
KKK of power_H_of_kink_ratioKK of Proposition 4.5 and K′=KS0K'=KS_0Lean's KK is K′K' of the text (10-05 Step 5)
Theorem namesmeasured_ratio—Different theorems with the same name in two bundles ((2) of §05)
Reading valuesNumerical theorems such as K_ff_C2, three_stage_3em4ReadingArithmetic with measured values put as assumptions. The grade of the values stays "Reading" (it does not become "Proved here" through the Lean label)
08

How the bundles are divided — by article, paper and subject

The bundles (files) are divided by subject (one proposition and its lemmas). It is usual for the theorems cited by one chapter or article to span several bundles, and the "Chapter" column of Table 1 gives the correspondence. There are four disciplines for dividing them.

This part places Assumption H at the axis of the study, and Lean was used for the algebraic steps of the construction of the first step. The viewpoint of doing proof checking in another form (for example, a formalisation that makes the objects themselves types) is taken up in Part 11.


What this chapter can say

Can sayCannot say
Lean The theorems of the bundles of Table 1 pass machine checking in a form that makes the assumptions explicit as arguments. In every bundle of Table 1, every line of the remaining #print axioms output is a subset of the three axiomsThe truth of the assumption rows. A check of reading Lean's real numbers as quantities of the path measure itself
The Lean theorems of the first step are all statements on real numbers, finite sums and sequences; there is no theorem that has measures or operators as typesA formalisation that makes measures and operators types
The four limits and how to guard against them (Table 3), the six questions for inspectionThat a claim that has passed the six questions is true (the questions are necessary checks, not sufficient ones)
That the layer of interval arithmetic is outside Lean, and only the assembly that puts the table as an assumption is inside LeanFormal verification of the implementation of interval arithmetic

Sources and reproduction

ItemKindSource, tool
The declarations and numbers of the theorems of the bundlesLeanWe read the declarations of the source of each bundle (Lean 4, Mathlib) and counted the theorem / lemma lines. Theorem names and assumptions are in each row of the text
Copy of the axiom outputLeanWe read the copy of the #print axioms output of each bundle and counted the absence of axiom names other than the three (sorryAx and others), after confirming with a control copy that contains such a name that it would be detected
The three axioms and #print axiomsCitedJ. Avigad, L. de Moura, S. Kong, S. Ullrich et al., "Theorem Proving in Lean 4", chapter Axioms and Computation
The layers of type and the characters on the side of the four-dimensional lattice (Table 2)This book10-02 §07 and the count in the correspondence table of the old version (the same 46 theorems)
Examples of the type that puts the conclusion into a definition and the type of a circle of dependenceThis bookA reading of two external documents that claim a construction or a proof (the sources are withheld and only the types are written; no judgement is made on whether the documents are right or wrong)

Terms used in this chapter — machine checking, bundle, the criterion of cleanness, the three axioms, #print axioms, native_decide, encoding of the objects, putting the conclusion into a definition, circle of dependence, negative-control theorem, translating conventions. Their meanings are in the A-02 glossary.

Next chapter: 10-14 Reconciliation — the numbers of the record and the known numbers — lays out, row by row against the numbers of the record, the distance between each condition of the first step and the nearest known theorem, a summary of the bibliographic checks, and the known numbers used for positive controls.

← 10-12 The integrated table and the dependency graphContents10-14 Reconciliation — the numbers of the record and the known numbers →

Revision 2026-10-09: first edition.
2026-10-09: for the four bundles whose "copy of the axiom output" in Table 1 was △ (HupBridge, RemVProxy, DetourKills, GlobalLyapunov), #print axioms was retaken on another computer and they were changed to ○.