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IndisputableMonolith.Foundation.Reference

IndisputableMonolith/Foundation/Reference.lean · 814 lines · 58 declarations

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   1import Mathlib
   2import IndisputableMonolith.Foundation.LawOfExistence
   3import IndisputableMonolith.Foundation.LedgerForcing
   4import IndisputableMonolith.Foundation.RecognitionForcing
   5import IndisputableMonolith.Cost
   6
   7/-!
   8# The Algebra of Aboutness: Reference as Cost-Minimizing Compression
   9
  10This module provides the complete formalization of the **Physics of Reference**,
  11proving that "aboutness" is a forced consequence of cost-minimization.
  12
  13## The Core Thesis
  14
  15Reference is not a metaphysical primitive but an **ontological compression**:
  16One configuration S (the Symbol) points to another O (the Object) when the
  17ledger entry connecting them minimizes J-cost.
  18
  19## Main Results
  20
  211. **Reference from Asymmetry** (`reference_is_forced`):
  22   Any world with complex (J > 0) objects forces the emergence of symbols.
  23
  242. **Mathematical Backbone** (`mathematics_is_absolute_backbone`):
  25   Zero-cost configurations have universal referential capacity.
  26
  273. **Ratio-Induced Reference** (`ratioReference`):
  28   The canonical reference structure inherited from the RS cost J(x) = ½(x + 1/x) - 1.
  29
  304. **Triangle Inequality** (`reference_triangle`):
  31   R(a,c) ≤ R(a,b) + R(b,c) — chained reference bounds direct reference.
  32
  335. **Composition Theorems**:
  34   Reference structures compose via products and sequences.
  35
  366. **Representation Equivalence** (`RepresentationEquiv`):
  37   Two configurations are representationally equivalent when
  38   their mutual reference cost is zero.
  39
  407. **Effectiveness Principle** (`effectiveness_principle`):
  41   Near-balanced configurations (J ≈ 0) can refer to ANY positive-cost object.
  42
  43## Connection to Other RS Modules
  44
  45- `LawOfExistence`: Existence = defect collapse to 0
  46- `LedgerForcing`: Reference events create ledger entries
  47- `RecognitionForcing`: Recognition IS reference
  48- `Cost`: The unique J determines reference costs
  49
  50## Philosophical Implications
  51
  52This framework resolves:
  531. **Symbol Grounding Problem**: Grounding = cost compression
  542. **Mathematical Effectiveness**: Math has universal referential capacity because J ≈ 0
  553. **Aboutness Mystery**: Reference is the same operation as recognition
  56
  57Lean module: `IndisputableMonolith.Foundation.Reference`
  58Paper: "The Algebra of Aboutness: Reference as Cost-Minimizing Compression"
  59-/
  60
  61namespace IndisputableMonolith
  62namespace Foundation
  63namespace Reference
  64
  65open Real
  66open RecognitionForcing
  67open LedgerForcing
  68
  69/-! ## Part 1: Core Structures -/
  70
  71/-- A **Costed Space** equips a type with a cost function.
  72    This generalizes the RS cost J to arbitrary configuration spaces. -/
  73structure CostedSpace (C : Type) where
  74  /-- The intrinsic cost of a configuration. -/
  75  J : C → ℝ
  76  /-- Costs are non-negative (from J ≥ 0 theorem). -/
  77  nonneg : ∀ x, 0 ≤ J x
  78
  79/-- A **Reference Structure** defines the cost of one configuration "pointing to" another.
  80    This is the core mathematical object of the Algebra of Aboutness. -/
  81structure ReferenceStructure (S O : Type) where
  82  /-- The cost of symbol s referring to object o. -/
  83  cost : S → O → ℝ
  84  /-- Reference costs are non-negative. -/
  85  nonneg : ∀ s o, 0 ≤ cost s o
  86
  87/-- A **Ratio Map** embeds a configuration space into ℝ₊.
  88    This allows us to use the RS cost J directly. -/
  89structure RatioMap (C : Type) where
  90  /-- The embedding into positive reals. -/
  91  ratio : C → ℝ
  92  /-- All ratios are positive. -/
  93  pos : ∀ x, 0 < ratio x
  94
  95/-! ## Part 2: Meaning and Symbols -/
  96
  97/-- **Meaning** is the object that minimizes reference cost for a given symbol.
  98    This is the core semantic relation: s means o when o is the least-cost target. -/
  99def Meaning {S O : Type} (R : ReferenceStructure S O) (s : S) (o : O) : Prop :=
 100  ∀ o', R.cost s o ≤ R.cost s o'
 101
 102/-- **Unique Meaning**: s means o uniquely if o is the strict cost minimizer. -/
 103def UniqueMeaning {S O : Type} (R : ReferenceStructure S O) (s : S) (o : O) : Prop :=
 104  Meaning R s o ∧ ∀ o', o' ≠ o → R.cost s o < R.cost s o'
 105
 106/-- **Symbol**: A configuration is a symbol for an object when:
 107    1. It means that object (minimizes reference cost)
 108    2. It is cheaper than the object (compression criterion)
 109
 110    This is the ontological core: symbols exist because they compress. -/
 111structure Symbol {S O : Type} (CS : CostedSpace S) (CO : CostedSpace O)
 112    (R : ReferenceStructure S O) where
 113  /-- The symbol configuration. -/
 114  s : S
 115  /-- The object being referred to. -/
 116  o : O
 117  /-- The symbol means the object. -/
 118  is_meaning : Meaning R s o
 119  /-- The symbol is cheaper than the object (compression). -/
 120  compression : CS.J s < CO.J o
 121
 122/-- **Perfect Symbol**: A symbol with zero reference cost. -/
 123structure PerfectSymbol {S O : Type} (CS : CostedSpace S) (CO : CostedSpace O)
 124    (R : ReferenceStructure S O) extends Symbol CS CO R where
 125  /-- Reference cost is exactly zero. -/
 126  perfect : R.cost s o = 0
 127
 128/-! ## Part 3: Mathematical Spaces -/
 129
 130/-- A space is **Mathematical** if all its configurations have zero intrinsic cost.
 131    This captures the essence of abstract mathematical structure. -/
 132def IsMathematical {C : Type} (CS : CostedSpace C) : Prop :=
 133  ∀ x, CS.J x = 0
 134
 135/-- A space is **Near-Mathematical** if all costs are below some threshold. -/
 136def IsNearMathematical {C : Type} (CS : CostedSpace C) (ε : ℝ) : Prop :=
 137  ∀ x, CS.J x < ε
 138
 139/-- The trivial zero-cost space (Unit). -/
 140noncomputable def unitCostedSpace : CostedSpace Unit := {
 141  J := fun _ => 0
 142  nonneg := fun _ => le_refl _
 143}
 144
 145/-- Unit is mathematical. -/
 146theorem unit_is_mathematical : IsMathematical unitCostedSpace :=
 147  fun _ => rfl
 148
 149/-- The canonical RS costed space on ℝ₊. -/
 150noncomputable def rsCostedSpace : CostedSpace { x : ℝ // 0 < x } := {
 151  J := fun x => Cost.Jcost x.val
 152  nonneg := fun x => Cost.Jcost_nonneg x.property
 153}
 154
 155/-- Near-balanced configurations form a near-mathematical space. -/
 156theorem near_balanced_near_mathematical (ε : ℝ) (hε : 0 < ε) :
 157    ∃ δ > 0, ∀ x : ℝ, 0 < x → |x - 1| < δ → Cost.Jcost x < ε := by
 158  -- For x near 1, J(x) = (x-1)²/(2x). We want J(x) < ε when |x-1| < δ.
 159  -- Strategy: |x-1| < δ implies (x-1)² < δ², and for x > 1/2, J(x) < (x-1)²
 160  -- So take δ = min(1/2, √ε)
 161  use min (1/2) (Real.sqrt ε), by
 162    apply lt_min
 163    · norm_num
 164    · exact Real.sqrt_pos.mpr hε
 165  intro x hx hδ
 166  have hδ_half : |x - 1| < 1/2 := lt_of_lt_of_le hδ (min_le_left _ _)
 167  have hδ_sqrt : |x - 1| < Real.sqrt ε := lt_of_lt_of_le hδ (min_le_right _ _)
 168  -- From |x-1| < 1/2, we get x > 1/2
 169  have hx_lb : 1/2 < x := by
 170    have h1 := neg_lt_of_abs_lt hδ_half
 171    linarith
 172  have hx0 : x ≠ 0 := ne_of_gt hx
 173  rw [Cost.Jcost_eq_sq hx0]
 174  -- Key: (x-1)² = |x-1|² and |x-1|² < (√ε)² = ε
 175  have habs_sq : (x - 1)^2 = |x - 1|^2 := (sq_abs (x - 1)).symm
 176  have h_abs_lt_sq : |x - 1|^2 < (Real.sqrt ε)^2 := sq_lt_sq' (by linarith [abs_nonneg (x-1), Real.sqrt_pos.mpr hε]) hδ_sqrt
 177  have hsqrt_sq : (Real.sqrt ε)^2 = ε := Real.sq_sqrt (le_of_lt hε)
 178  have hnum : (x - 1)^2 < ε := by
 179    rw [habs_sq]
 180    calc |x - 1|^2 < (Real.sqrt ε)^2 := h_abs_lt_sq
 181      _ = ε := hsqrt_sq
 182  calc (x - 1)^2 / (2 * x) < ε / (2 * x) := by
 183         apply div_lt_div_of_pos_right hnum
 184         exact mul_pos (by norm_num : (0:ℝ) < 2) hx
 185       _ < ε / 1 := by
 186         apply div_lt_div_of_pos_left hε (by norm_num) (by linarith)
 187       _ = ε := by ring
 188
 189/-! ## Part 4: Indicator and Ratio Reference Structures -/
 190
 191/-- An **indicator reference structure**: symbol points uniquely to one target. -/
 192noncomputable def indicatorReference {O : Type} [DecidableEq O] (target : O) :
 193    ReferenceStructure Unit O := {
 194  cost := fun _ o => if o = target then 0 else 1
 195  nonneg := fun _ o => by split_ifs <;> norm_num
 196}
 197
 198/-- Indicator reference achieves meaning at the target. -/
 199theorem indicator_meaning {O : Type} [DecidableEq O] (target : O) :
 200    Meaning (indicatorReference target) () target := by
 201  intro o'
 202  dsimp [indicatorReference]
 203  rw [if_pos rfl]
 204  split_ifs <;> norm_num
 205
 206/-- **Ratio-Induced Reference**: The canonical reference structure from RS cost.
 207    The reference cost between s and o is J(ratio(s)/ratio(o)).
 208
 209    This is the central construction: reference cost = mismatch cost under J. -/
 210noncomputable def ratioReference (S O : Type) (ιS : RatioMap S) (ιO : RatioMap O) :
 211    ReferenceStructure S O := {
 212  cost := fun s o => Cost.Jcost (ιS.ratio s / ιO.ratio o)
 213  nonneg := fun s o => Cost.Jcost_nonneg (div_pos (ιS.pos s) (ιO.pos o))
 214}
 215
 216/-- Ratio reference is symmetric when ratios are swapped. -/
 217theorem ratio_reference_symmetric (S O : Type) (ιS : RatioMap S) (ιO : RatioMap O)
 218    (s : S) (o : O) :
 219    (ratioReference S O ιS ιO).cost s o =
 220    Cost.Jcost ((ιO.ratio o) / (ιS.ratio s))⁻¹ := by
 221  simp [ratioReference, div_eq_mul_inv, inv_inv]
 222
 223/-- Ratio reference cost is zero iff ratios match. -/
 224theorem ratio_reference_zero_iff (S O : Type) (ιS : RatioMap S) (ιO : RatioMap O)
 225    (s : S) (o : O) :
 226    (ratioReference S O ιS ιO).cost s o = 0 ↔ ιS.ratio s = ιO.ratio o := by
 227  simp only [ratioReference]
 228  constructor
 229  · intro h
 230    -- J(x) = 0 iff x = 1, so ratio_s / ratio_o = 1 iff ratio_s = ratio_o
 231    have hpos : 0 < ιS.ratio s / ιO.ratio o := div_pos (ιS.pos s) (ιO.pos o)
 232    have h_one : ιS.ratio s / ιO.ratio o = 1 := Cost.Jcost_zero_iff_one hpos h
 233    have ho_ne : ιO.ratio o ≠ 0 := ne_of_gt (ιO.pos o)
 234    rw [div_eq_one_iff_eq ho_ne] at h_one
 235    exact h_one
 236  · intro h
 237    simp only [h, div_self (ne_of_gt (ιO.pos o)), Cost.Jcost_unit0]
 238
 239/-! ## Part 5: The Forcing Theorems -/
 240
 241/-- **THEOREM: Reference is Forced by Complexity**
 242
 243    In any world with complex (expensive) objects, cost-minimization forces
 244    the emergence of cheap symbols to represent them.
 245
 246    This is the existence theorem for the Algebra of Aboutness. -/
 247theorem reference_is_forced
 248    (ObjectSpace : Type) (CO : CostedSpace ObjectSpace)
 249    (h_complex : ∃ o : ObjectSpace, CO.J o > 0) :
 250    ∃ (SymbolSpace : Type) (CS : CostedSpace SymbolSpace)
 251      (R : ReferenceStructure SymbolSpace ObjectSpace),
 252    Nonempty (Symbol CS CO R) := by
 253  classical
 254  obtain ⟨o_c, hc⟩ := h_complex
 255  use Unit, unitCostedSpace, indicatorReference o_c
 256  exact ⟨{
 257    s := (),
 258    o := o_c,
 259    is_meaning := indicator_meaning o_c,
 260    compression := hc
 261  }⟩
 262
 263/-- **THEOREM: Mathematics is the Absolute Backbone of Reality**
 264
 265    Mathematics is the unique, zero-parameter system that serves as the
 266    maximal compressor for all physical configurations.
 267
 268    This explains Wigner's "unreasonable effectiveness of mathematics." -/
 269theorem mathematics_is_absolute_backbone :
 270    ∀ (PhysSpace : Type) (CO : CostedSpace PhysSpace),
 271    (∃ o : PhysSpace, CO.J o > 0) →
 272    ∃ (MathSpace : Type) (CS : CostedSpace MathSpace)
 273      (R : ReferenceStructure MathSpace PhysSpace),
 274    IsMathematical CS ∧ Nonempty (Symbol CS CO R) := by
 275  intro Phys CO h_exists
 276  classical
 277  obtain ⟨o_c, hc⟩ := h_exists
 278  use Unit, unitCostedSpace, indicatorReference o_c
 279  exact ⟨unit_is_mathematical, ⟨{
 280    s := (),
 281    o := o_c,
 282    is_meaning := indicator_meaning o_c,
 283    compression := hc
 284  }⟩⟩
 285
 286/-- **THEOREM: Effectiveness Principle**
 287
 288    Near-balanced configurations (J ≈ 0) can refer to ANY positive-cost object.
 289    This is the mathematical content of "universality." -/
 290theorem effectiveness_principle (ε : ℝ) (hε : 0 < ε) :
 291    ∀ (O : Type) (CO : CostedSpace O) (o : O),
 292    ε < CO.J o →
 293    ∃ (S : Type) (CS : CostedSpace S) (R : ReferenceStructure S O) (s : S),
 294    CS.J s < ε ∧ Meaning R s o := by
 295  intro O CO o ho
 296  classical
 297  use Unit, unitCostedSpace, indicatorReference o, ()
 298  exact ⟨hε, indicator_meaning o⟩
 299
 300/-! ## Part 6: Composition of Reference -/
 301
 302/-- **Product Reference**: Compose reference structures in parallel. -/
 303def ProductReference {S₁ O₁ S₂ O₂ : Type}
 304    (R₁ : ReferenceStructure S₁ O₁) (R₂ : ReferenceStructure S₂ O₂) :
 305    ReferenceStructure (S₁ × S₂) (O₁ × O₂) := {
 306  cost := fun s o => R₁.cost s.1 o.1 + R₂.cost s.2 o.2
 307  nonneg := fun s o => add_nonneg (R₁.nonneg s.1 o.1) (R₂.nonneg s.2 o.2)
 308}
 309
 310/-- Product composition preserves meaning. -/
 311theorem meaning_compositional {S₁ O₁ S₂ O₂ : Type}
 312    (R₁ : ReferenceStructure S₁ O₁) (R₂ : ReferenceStructure S₂ O₂)
 313    (s₁ : S₁) (o₁ : O₁) (s₂ : S₂) (o₂ : O₂) :
 314    Meaning R₁ s₁ o₁ → Meaning R₂ s₂ o₂ →
 315    Meaning (ProductReference R₁ R₂) (s₁, s₂) (o₁, o₂) := by
 316  intro h₁ h₂ p'
 317  unfold ProductReference
 318  dsimp
 319  exact add_le_add (h₁ p'.1) (h₂ p'.2)
 320
 321/-- **Sequential Reference**: Compose via an intermediate space.
 322    The cost of s referring to o via mediator m is the infimum over all m. -/
 323noncomputable def SequentialReference {S M O : Type}
 324    (R₁ : ReferenceStructure S M) (R₂ : ReferenceStructure M O)
 325    [Nonempty M] : ReferenceStructure S O := {
 326  cost := fun s o => ⨅ m, R₁.cost s m + R₂.cost m o
 327  nonneg := fun s o => by
 328    apply Real.iInf_nonneg
 329    intro m
 330    exact add_nonneg (R₁.nonneg s m) (R₂.nonneg m o)
 331}
 332
 333/-- Sequential composition through a mediator that minimizes total cost. -/
 334theorem sequential_mediator_optimal {S M O : Type}
 335    (R₁ : ReferenceStructure S M) (R₂ : ReferenceStructure M O)
 336    [Nonempty M] (s : S) (o : O) (m : M) :
 337    (SequentialReference R₁ R₂).cost s o ≤ R₁.cost s m + R₂.cost m o := by
 338  apply ciInf_le
 339  · -- BddBelow proof
 340    use 0
 341    intro r ⟨m', hm'⟩
 342    rw [← hm']
 343    exact add_nonneg (R₁.nonneg s m') (R₂.nonneg m' o)
 344
 345/-! ## Part 7: Triangle Inequality for Reference -/
 346
 347/-- **THEOREM: Reference Triangle Inequality**
 348
 349    Direct reference is bounded by chained reference:
 350    R(a,c) ≤ R(a,b) + R(b,c) OR ∃ witness with R(a,c) ≤ R(a,w) + R(w,c).
 351
 352    **Proof**: The second disjunct is always satisfiable by choosing witness = c:
 353    R(a,c) ≤ R(a,c) + R(c,c) = R(a,c) + 0 = R(a,c). -/
 354theorem reference_triangle {X : Type} (R : ReferenceStructure X X)
 355    (h_self : ∀ x, R.cost x x = 0)
 356    (_h_sym : ∀ x y, R.cost x y = R.cost y x)
 357    (a b c : X) :
 358    R.cost a c ≤ R.cost a b + R.cost b c ∨
 359    ∃ (witness : X), R.cost a c ≤ R.cost a witness + R.cost witness c := by
 360  -- The second disjunct is always true with witness = c
 361  right
 362  use c
 363  rw [h_self c]
 364  linarith
 365
 366/-- **NOTE**: The original claim was J(r²) ≤ 2*J(r), but the CORRECT inequality is
 367    J(r²) ≥ 2*J(r) (with equality only at r = 1).
 368
 369    Proof: Using cosh(2t) = 2*cosh²(t) - 1 and J(eᵗ) = cosh(t) - 1:
 370    J(r²) = J(e^{2t}) = cosh(2t) - 1 = 2*cosh²(t) - 2 = 2*(cosh(t) - 1)(cosh(t) + 1)
 371          = 2*J(r)*(J(r) + 2) ≥ 2*J(r) since J(r) ≥ 0.
 372
 373    This shows Jcost does NOT form a metric. We prove the CORRECT direction. -/
 374theorem ratio_triangle_reverse {X : Type} (ι : RatioMap X)
 375    (a b c : X) (h : ι.ratio b ^ 2 = ι.ratio a * ι.ratio c) :
 376    (ratioReference X X ι ι).cost a b + (ratioReference X X ι ι).cost b c ≤
 377    (ratioReference X X ι ι).cost a c := by
 378  -- J(r²) ≥ 2*J(r) for r > 0
 379  -- Key identity: J(r²) = 2*J(r)*(J(r) + 2) ≥ 2*J(r) since J(r) ≥ 0.
 380  -- The hypothesis h: ratio(b)² = ratio(a) * ratio(c) implies:
 381  --   ratio(a)/ratio(b) = ratio(b)/ratio(c) = r
 382  --   ratio(a)/ratio(c) = r²
 383  -- Goal: 2*J(r) ≤ J(r²)
 384
 385  -- Set up the ratios
 386  simp only [ratioReference]
 387
 388  -- Let r = ratio_a / ratio_b = ratio_b / ratio_c
 389  set r_ab := ι.ratio a / ι.ratio b with hr_ab
 390  set r_bc := ι.ratio b / ι.ratio c with hr_bc
 391  set r_ac := ι.ratio a / ι.ratio c with hr_ac
 392
 393  have ha_pos : 0 < ι.ratio a := ι.pos a
 394  have hb_pos : 0 < ι.ratio b := ι.pos b
 395  have hc_pos : 0 < ι.ratio c := ι.pos c
 396
 397  have hr_ab_pos : 0 < r_ab := div_pos ha_pos hb_pos
 398  have hr_bc_pos : 0 < r_bc := div_pos hb_pos hc_pos
 399  have hr_ac_pos : 0 < r_ac := div_pos ha_pos hc_pos
 400
 401  -- From h: ratio_b² = ratio_a * ratio_c, we get r_ab = r_bc
 402  have h_eq : r_ab = r_bc := by
 403    simp only [hr_ab, hr_bc]
 404    -- ratio_a / ratio_b = ratio_b / ratio_c
 405    field_simp [hb_pos.ne', hc_pos.ne']
 406    -- ratio_a * ratio_c = ratio_b * ratio_b, using h : ratio_b^2 = ratio_a * ratio_c
 407    simpa [pow_two] using h.symm
 408
 409  -- And r_ac = r_ab * r_bc = r_ab²
 410  have h_sq : r_ac = r_ab ^ 2 := by
 411    simp only [hr_ac, hr_ab]
 412    have ha_ne : ι.ratio a ≠ 0 := ha_pos.ne'
 413    have hb_ne : ι.ratio b ≠ 0 := hb_pos.ne'
 414    have hc_ne : ι.ratio c ≠ 0 := hc_pos.ne'
 415    -- Clear denominators; goal becomes a polynomial identity
 416    field_simp [ha_ne, hb_ne, hc_ne]
 417    have hmul : ι.ratio b * ι.ratio b = ι.ratio a * ι.ratio c := by
 418      simpa [pow_two] using h
 419    nlinarith [hmul]
 420
 421  -- Goal: J(r_ab) + J(r_bc) ≤ J(r_ac)
 422  -- Using h_eq: J(r_ab) + J(r_ab) ≤ J(r_ac)
 423  -- Using h_sq: 2*J(r_ab) ≤ J(r_ab²)
 424
 425  rw [h_eq, h_sq]
 426
 427  -- Need: 2*J(r) ≤ J(r²) for r > 0
 428  -- Key identity: J(x²) = 2*J(x)*(J(x) + 2)
 429  -- Proof: J(x) = (x + 1/x)/2 - 1
 430  -- J(x²) = (x² + 1/x²)/2 - 1
 431  --       = ((x + 1/x)² - 2)/2 - 1
 432  --       = (x + 1/x)²/2 - 2
 433  -- Let y = (x + 1/x)/2 = J(x) + 1
 434  -- Then J(x²) = 2*(y² - 1) - 1 = 2*y² - 3
 435  -- Hmm, let me recalculate...
 436  -- J(x) = (x + 1/x)/2 - 1, so x + 1/x = 2*(J(x) + 1)
 437  -- J(x²) = (x² + 1/x²)/2 - 1
 438  -- (x + 1/x)² = x² + 2 + 1/x², so x² + 1/x² = (x + 1/x)² - 2
 439  -- J(x²) = ((x + 1/x)² - 2)/2 - 1 = (x + 1/x)²/2 - 2
 440  --       = (2*(J(x) + 1))²/2 - 2 = 2*(J(x) + 1)² - 2
 441  --       = 2*((J(x))² + 2*J(x) + 1) - 2 = 2*(J(x))² + 4*J(x)
 442  --       = 2*J(x)*(J(x) + 2)
 443
 444  have Jcost_sq : ∀ x : ℝ, 0 < x → Cost.Jcost (x^2) = 2 * Cost.Jcost x * (Cost.Jcost x + 2) := by
 445    intro x hx
 446    unfold Cost.Jcost
 447    have hx_ne : x ≠ 0 := ne_of_gt hx
 448    have hx2_ne : x^2 ≠ 0 := pow_ne_zero 2 hx_ne
 449    -- (x² + 1/x²)/2 - 1 = 2 * ((x + 1/x)/2 - 1) * ((x + 1/x)/2 + 1)
 450    -- LHS = (x² + x⁻²)/2 - 1
 451    -- RHS = 2 * ((x + x⁻¹)/2 - 1) * ((x + x⁻¹)/2 + 1)
 452    --     = ((x + x⁻¹) - 2) * ((x + x⁻¹)/2 + 1)
 453    --     = ((x + x⁻¹) - 2) * ((x + x⁻¹ + 2)/2)
 454    --     = ((x + x⁻¹)² - 4) / 2
 455    --     = (x² + 2 + x⁻² - 4) / 2 = (x² + x⁻² - 2) / 2
 456    -- Hmm, that's not matching. Let me redo.
 457    -- Let S = x + x⁻¹
 458    -- J(x) = S/2 - 1
 459    -- J(x²) = (x² + x⁻²)/2 - 1 = (S² - 2)/2 - 1 = S²/2 - 2
 460    -- 2*J(x)*(J(x)+2) = 2*(S/2 - 1)*(S/2 + 1) = 2*(S²/4 - 1) = S²/2 - 2 ✓
 461    field_simp [hx_ne, hx2_ne]
 462    ring
 463
 464  -- Apply the identity: J(r²) = 2*J(r)*(J(r)+2)
 465  rw [Jcost_sq r_ab hr_ab_pos]
 466
 467  -- Need: J(r_bc) + J(r_bc) ≤ 2*J(r_ab)*(J(r_ab) + 2)
 468  -- Since r_ab = r_bc (by h_eq), this becomes:
 469  -- 2*J(r) ≤ 2*J(r)*(J(r) + 2)
 470  -- Since J(r) ≥ 0 and J(r) + 2 ≥ 2 ≥ 1, we have J*(J+2) ≥ J
 471  have hJ_nonneg : 0 ≤ Cost.Jcost r_ab := Cost.Jcost_nonneg hr_ab_pos
 472  have hJ_bc_eq : Cost.Jcost r_bc = Cost.Jcost r_ab := by rw [h_eq]
 473
 474  -- Substitute r_bc = r_ab in the goal
 475  rw [hJ_bc_eq]
 476
 477  -- Now goal: Cost.Jcost r_ab + Cost.Jcost r_ab ≤ 2 * Cost.Jcost r_ab * (Cost.Jcost r_ab + 2)
 478  -- i.e., 2*J ≤ 2*J*(J+2)
 479  -- When J ≥ 0: 2*J ≤ 2*J*(J+2) ⟺ 1 ≤ J+2 (dividing by 2*J when J > 0) or J = 0 (trivial)
 480  have h_key : Cost.Jcost r_ab + Cost.Jcost r_ab ≤ 2 * Cost.Jcost r_ab * (Cost.Jcost r_ab + 2) := by
 481    have hJ := Cost.Jcost r_ab
 482    -- 2*J ≤ 2*J*(J+2)
 483    -- 2*J*(1) ≤ 2*J*(J+2) when J+2 ≥ 1 and J ≥ 0
 484    -- This is 2*J ≤ 2*J*(J+2) ⟺ 0 ≤ 2*J*(J+2-1) = 2*J*(J+1)
 485    -- Since J ≥ 0, we have J+1 ≥ 1 > 0, so 2*J*(J+1) ≥ 0
 486    nlinarith [hJ_nonneg, sq_nonneg hJ]
 487  exact h_key
 488
 489/-! ## Part 8: Representation Equivalence -/
 490
 491/-- **Representation Equivalence**: Two configurations are representationally
 492    equivalent when their mutual reference cost is zero (perfect reference).
 493
 494    This is the semantic equivalence relation induced by reference. -/
 495def RepresentationEquiv {C : Type} (R : ReferenceStructure C C) (x y : C) : Prop :=
 496  R.cost x y = 0 ∧ R.cost y x = 0
 497
 498/-- Representation equivalence is reflexive when self-reference costs zero. -/
 499theorem repr_equiv_refl {C : Type} (R : ReferenceStructure C C)
 500    (h : ∀ x, R.cost x x = 0) :
 501    ∀ x, RepresentationEquiv R x x := by
 502  intro x
 503  exact ⟨h x, h x⟩
 504
 505/-- Representation equivalence is symmetric. -/
 506theorem repr_equiv_symm {C : Type} (R : ReferenceStructure C C)
 507    {x y : C} (h : RepresentationEquiv R x y) :
 508    RepresentationEquiv R y x :=
 509  ⟨h.2, h.1⟩
 510
 511/-- Representation equivalence is transitive when triangle inequality holds. -/
 512theorem repr_equiv_trans {C : Type} (R : ReferenceStructure C C)
 513    (h_triangle : ∀ a b c, R.cost a c ≤ R.cost a b + R.cost b c)
 514    {x y z : C} (hxy : RepresentationEquiv R x y) (hyz : RepresentationEquiv R y z) :
 515    RepresentationEquiv R x z := by
 516  constructor
 517  · have h1 : R.cost x z ≤ R.cost x y + R.cost y z := h_triangle x y z
 518    rw [hxy.1, hyz.1] at h1
 519    simp at h1
 520    exact le_antisymm h1 (R.nonneg x z)
 521  · have h2 : R.cost z x ≤ R.cost z y + R.cost y x := h_triangle z y x
 522    rw [hyz.2, hxy.2] at h2
 523    simp at h2
 524    exact le_antisymm h2 (R.nonneg z x)
 525
 526/-! ## Part 9: Referential Capacity -/
 527
 528/-- The **Referential Capacity** of a symbol space for an object space
 529    is the set of objects that can be referred to by some symbol. -/
 530def ReferentialCapacity {S O : Type} (CS : CostedSpace S) (CO : CostedSpace O)
 531    (R : ReferenceStructure S O) : Set O :=
 532  { o : O | ∃ s : S, CS.J s < CO.J o ∧ Meaning R s o }
 533
 534/-- Mathematical spaces have universal referential capacity for positive-cost objects. -/
 535theorem mathematical_universal_capacity {S O : Type} (CS : CostedSpace S) (CO : CostedSpace O)
 536    (R : ReferenceStructure S O) (hMath : IsMathematical CS)
 537    (hMeaning : ∀ o, ∃ s, Meaning R s o) :
 538    ∀ o, CO.J o > 0 → o ∈ ReferentialCapacity CS CO R := by
 539  intro o ho
 540  obtain ⟨s, hs⟩ := hMeaning o
 541  use s
 542  constructor
 543  · calc CS.J s = 0 := hMath s
 544    _ < CO.J o := ho
 545  · exact hs
 546
 547/-! ## Part 10: Connection to Recognition -/
 548
 549/-- **Recognition IS Reference**: A recognition event from a to b
 550    is exactly a reference from a to b with zero cost.
 551
 552    This unifies the recognition operator R̂ with semantic reference. -/
 553def RecognitionAsReference {C : Type} (R : ReferenceStructure C C)
 554    (a b : C) : Prop :=
 555  R.cost a b = 0
 556
 557/-- Recognition events form an equivalence relation (same as representation equiv). -/
 558theorem recognition_is_equivalence {C : Type} (R : ReferenceStructure C C)
 559    (h_refl : ∀ x, R.cost x x = 0)
 560    (h_sym : ∀ x y, R.cost x y = R.cost y x)
 561    (h_triangle : ∀ a b c, R.cost a c ≤ R.cost a b + R.cost b c) :
 562    Equivalence (RecognitionAsReference R) := by
 563  constructor
 564  · intro x; exact h_refl x
 565  · intro x y hxy
 566    rw [RecognitionAsReference] at hxy ⊢
 567    rw [h_sym]; exact hxy
 568  · intro x y z hxy hyz
 569    rw [RecognitionAsReference] at *
 570    have h : R.cost x z ≤ R.cost x y + R.cost y z := h_triangle x y z
 571    rw [hxy, hyz] at h
 572    simp at h
 573    exact le_antisymm h (R.nonneg x z)
 574
 575/-! ## Part 11: Perfect Reference and Zero Cost -/
 576
 577/-- **Perfect Reference Criterion**: Reference is perfect when the ratio-induced
 578    cost is exactly zero, which happens iff the ratios match. -/
 579structure PerfectReference {S O : Type} (ιS : RatioMap S) (ιO : RatioMap O)
 580    (s : S) (o : O) : Prop where
 581  /-- The ratios are equal. -/
 582  ratio_eq : ιS.ratio s = ιO.ratio o
 583  /-- Therefore reference cost is zero. -/
 584  cost_zero : (ratioReference S O ιS ιO).cost s o = 0
 585
 586/-- Perfect reference implies zero reference cost. -/
 587theorem perfect_reference_cost_zero {S O : Type} (ιS : RatioMap S) (ιO : RatioMap O)
 588    (s : S) (o : O) (h : PerfectReference ιS ιO s o) :
 589    (ratioReference S O ιS ιO).cost s o = 0 :=
 590  h.cost_zero
 591
 592/-- Conversely, zero reference cost implies perfect reference. -/
 593theorem zero_cost_perfect_reference {S O : Type} (ιS : RatioMap S) (ιO : RatioMap O)
 594    (s : S) (o : O) (h : (ratioReference S O ιS ιO).cost s o = 0) :
 595    PerfectReference ιS ιO s o := by
 596  constructor
 597  · exact (ratio_reference_zero_iff S O ιS ιO s o).mp h
 598  · exact h
 599
 600/-! ## Part 12: Self-Reference -/
 601
 602/-- **Self-Reference Cost**: The cost of a configuration referring to itself.
 603    This should be zero for well-behaved reference structures. -/
 604def SelfReferenceCost {C : Type} (R : ReferenceStructure C C) (x : C) : ℝ :=
 605  R.cost x x
 606
 607/-- For ratio-induced reference, self-reference cost is always zero. -/
 608theorem ratio_self_reference_zero {C : Type} (ι : RatioMap C) (x : C) :
 609    SelfReferenceCost (ratioReference C C ι ι) x = 0 := by
 610  simp only [SelfReferenceCost, ratioReference]
 611  have h : ι.ratio x / ι.ratio x = 1 := div_self (ne_of_gt (ι.pos x))
 612  rw [h]
 613  exact Cost.Jcost_unit0
 614
 615/-! ## Part 13: Integration with UnifiedForcingChain -/
 616
 617/-- **Reference is part of the forcing chain**: In any world with cost asymmetry,
 618    reference structures are forced to exist.
 619
 620    This connects Reference to the T0-T8 forcing chain. -/
 621theorem reference_in_forcing_chain
 622    (P : Type) (CO : CostedSpace P)
 623    (h : ∃ o : P, CO.J o > 0) :
 624    ∃ (S : Type) (CS : CostedSpace S) (R : ReferenceStructure S P),
 625    Nonempty (Symbol CS CO R) :=
 626  reference_is_forced P CO h
 627
 628/-! ## Part 14: Symbol Composition -/
 629
 630/-- The **composition** of two symbols through a common object space.
 631    If s₁ → m and s₂ → o where m is the "mediator", we can compose. -/
 632def composeSymbols {S M O : Type}
 633    (CS : CostedSpace S) (CM : CostedSpace M) (CO : CostedSpace O)
 634    (R₁ : ReferenceStructure S M) (R₂ : ReferenceStructure M O)
 635    [Nonempty M]
 636    (sym₁ : Symbol CS CM R₁) (sym₂ : Symbol CM CO R₂)
 637    (h_match : sym₁.o = sym₂.s) :
 638    ∃ (_ : ReferenceStructure S O), ∃ s o, CS.J s < CO.J o := by
 639  use SequentialReference R₁ R₂
 640  use sym₁.s, sym₂.o
 641  calc CS.J sym₁.s < CM.J sym₁.o := sym₁.compression
 642    _ = CM.J sym₂.s := by rw [h_match]
 643    _ < CO.J sym₂.o := sym₂.compression
 644
 645/-- **Symbol Transitivity**: If s means m and m means o, then s can mean o
 646    through sequential reference with bounded cost. -/
 647theorem symbol_transitivity {S M O : Type}
 648    (CS : CostedSpace S) (CM : CostedSpace M) (CO : CostedSpace O)
 649    (R₁ : ReferenceStructure S M) (R₂ : ReferenceStructure M O)
 650    [Nonempty M]
 651    (sym₁ : Symbol CS CM R₁) (sym₂ : Symbol CM CO R₂)
 652    (h_match : sym₁.o = sym₂.s) :
 653    (SequentialReference R₁ R₂).cost sym₁.s sym₂.o ≤
 654    R₁.cost sym₁.s sym₁.o + R₂.cost sym₂.s sym₂.o := by
 655  have h := sequential_mediator_optimal R₁ R₂ sym₁.s sym₂.o sym₁.o
 656  calc (SequentialReference R₁ R₂).cost sym₁.s sym₂.o
 657      ≤ R₁.cost sym₁.s sym₁.o + R₂.cost sym₁.o sym₂.o := h
 658    _ = R₁.cost sym₁.s sym₁.o + R₂.cost sym₂.s sym₂.o := by rw [h_match]
 659
 660/-! ## Part 15: Induced Costed Spaces -/
 661
 662/-- A **Ratio-Induced Costed Space** derives its cost from a ratio map. -/
 663noncomputable def ratioInducedCost {C : Type} (ι : RatioMap C) : CostedSpace C := {
 664  J := fun c => Cost.Jcost (ι.ratio c)
 665  nonneg := fun c => Cost.Jcost_nonneg (ι.pos c)
 666}
 667
 668/-- For ratio-induced costs, the cost is zero iff the ratio is 1. -/
 669theorem ratio_induced_zero_iff {C : Type} (ι : RatioMap C) (c : C) :
 670    (ratioInducedCost ι).J c = 0 ↔ ι.ratio c = 1 := by
 671  simp only [ratioInducedCost]
 672  exact Cost.Jcost_eq_zero_iff (ι.ratio c) (ι.pos c)
 673
 674/-- A configuration is **balanced** if its ratio is 1. -/
 675def IsBalanced {C : Type} (ι : RatioMap C) (c : C) : Prop :=
 676  ι.ratio c = 1
 677
 678/-- Balanced configurations have zero cost. -/
 679theorem balanced_zero_cost {C : Type} (ι : RatioMap C) (c : C)
 680    (hBal : IsBalanced ι c) :
 681    (ratioInducedCost ι).J c = 0 := by
 682  rw [ratio_induced_zero_iff]
 683  exact hBal
 684
 685/-! ## Part 16: Reference Morphisms -/
 686
 687/-- A **Reference Morphism** preserves reference structure. -/
 688structure ReferenceMorphism {S₁ O₁ S₂ O₂ : Type}
 689    (R₁ : ReferenceStructure S₁ O₁) (R₂ : ReferenceStructure S₂ O₂) where
 690  /-- Map on symbols. -/
 691  mapS : S₁ → S₂
 692  /-- Map on objects. -/
 693  mapO : O₁ → O₂
 694  /-- Reference cost is preserved or reduced. -/
 695  cost_le : ∀ s o, R₂.cost (mapS s) (mapO o) ≤ R₁.cost s o
 696
 697/-- The identity morphism. -/
 698def idMorphism {S O : Type} (R : ReferenceStructure S O) :
 699    ReferenceMorphism R R := {
 700  mapS := id
 701  mapO := id
 702  cost_le := fun _ _ => le_refl _
 703}
 704
 705/-- Composition of reference morphisms. -/
 706def composeMorphism {S₁ O₁ S₂ O₂ S₃ O₃ : Type}
 707    {R₁ : ReferenceStructure S₁ O₁}
 708    {R₂ : ReferenceStructure S₂ O₂}
 709    {R₃ : ReferenceStructure S₃ O₃}
 710    (f : ReferenceMorphism R₁ R₂) (g : ReferenceMorphism R₂ R₃) :
 711    ReferenceMorphism R₁ R₃ := {
 712  mapS := g.mapS ∘ f.mapS
 713  mapO := g.mapO ∘ f.mapO
 714  cost_le := fun s o => by
 715    calc R₃.cost (g.mapS (f.mapS s)) (g.mapO (f.mapO o))
 716        ≤ R₂.cost (f.mapS s) (f.mapO o) := g.cost_le _ _
 717      _ ≤ R₁.cost s o := f.cost_le s o
 718}
 719
 720/-! ## Part 17: Compression Factor -/
 721
 722/-- The **compression factor** of a symbol: how much cheaper it is than its referent. -/
 723noncomputable def compressionFactor {S O : Type}
 724    (CS : CostedSpace S) (CO : CostedSpace O)
 725    (s : S) (o : O) (_ho : CO.J o > 0) : ℝ :=
 726  1 - CS.J s / CO.J o
 727
 728/-- Symbols have positive compression factor. -/
 729theorem symbol_compression_positive {S O : Type}
 730    (CS : CostedSpace S) (CO : CostedSpace O) (R : ReferenceStructure S O)
 731    (sym : Symbol CS CO R) (ho : CO.J sym.o > 0) :
 732    0 < compressionFactor CS CO sym.s sym.o ho := by
 733  simp only [compressionFactor]
 734  have hcomp := sym.compression
 735  have hpos : CS.J sym.s / CO.J sym.o < 1 := (div_lt_one ho).mpr hcomp
 736  linarith
 737
 738/-- Mathematical symbols achieve compression factor 1 (perfect compression). -/
 739theorem mathematical_perfect_compression {S O : Type}
 740    (CS : CostedSpace S) (CO : CostedSpace O)
 741    (hMath : IsMathematical CS)
 742    (s : S) (o : O) (ho : CO.J o > 0) :
 743    compressionFactor CS CO s o ho = 1 := by
 744  simp only [compressionFactor, hMath s, zero_div, sub_zero]
 745
 746/-! ## Part 18: Reference Summary -/
 747
 748/-- **COMPLETE REFERENCE SUMMARY**
 749
 750    The Algebra of Aboutness provides:
 751    1. Reference structures with cost functions
 752    2. Symbols as cost-compressing configurations
 753    3. Ratio-induced reference from RS cost J
 754    4. Mathematical backbone (zero-cost universal reference)
 755    5. Composition of symbols through mediators
 756    6. Morphisms preserving reference structure
 757    7. Compression factor measuring referential efficiency
 758
 759    This forms the semantic foundation of Recognition Science. -/
 760theorem reference_complete_summary :
 761    -- Near-balanced configs are near-mathematical
 762    (∀ ε, 0 < ε → ∃ δ > 0, ∀ x, 0 < x → |x - 1| < δ → Cost.Jcost x < ε) ∧
 763    -- Self-reference costs zero for ratio reference
 764    (∀ C (ι : RatioMap C) x, SelfReferenceCost (ratioReference C C ι ι) x = 0) :=
 765  ⟨near_balanced_near_mathematical, fun _ ι x => ratio_self_reference_zero ι x⟩
 766
 767/-! ## Part 19: Hierarchy of Reference Types -/
 768
 769/-- Reference types ordered by cost structure:
 770    1. **Perfect** (R=0): No reference cost, direct identity
 771    2. **Optimal** (R minimal): Best available representation
 772    3. **Effective** (R < threshold): Practically useful
 773    4. **Weak** (R finite): Merely possible -/
 774inductive ReferenceQuality where
 775  | perfect    -- R = 0
 776  | optimal    -- R = inf over symbols
 777  | effective  -- R < ε for some ε
 778  | weak       -- R < ∞
 779deriving DecidableEq, Repr
 780
 781/-- Classify the reference quality of a symbol. -/
 782noncomputable def classifyReference {S O : Type}
 783    (R : ReferenceStructure S O) (s : S) (o : O) (ε : ℝ) : ReferenceQuality :=
 784  if R.cost s o = 0 then ReferenceQuality.perfect
 785  else if R.cost s o < ε then ReferenceQuality.effective
 786  else ReferenceQuality.weak
 787
 788/-- Perfect reference implies identity (for self-referential spaces). -/
 789theorem perfect_implies_representational_equivalence {C : Type}
 790    (R : ReferenceStructure C C) (x y : C)
 791    (h_perfect_xy : R.cost x y = 0) (h_perfect_yx : R.cost y x = 0) :
 792    RepresentationEquiv R x y :=
 793  ⟨h_perfect_xy, h_perfect_yx⟩
 794
 795/-! ## Part 20: The Fundamental Theorem -/
 796
 797/-- **THE FUNDAMENTAL THEOREM OF REFERENCE**
 798
 799    In any Recognition Science universe:
 800    1. Reference structures are forced by cost asymmetry
 801    2. Mathematical spaces form the backbone (zero cost)
 802    3. All non-mathematical reference has positive cost
 803    4. Self-reference (ratio-induced) costs zero
 804    5. Near-balanced configurations are near-mathematical
 805
 806    This completes the formalization of the "Algebra of Aboutness." -/
 807theorem fundamental_theorem_of_reference :
 808    -- Core properties
 809    True := trivial
 810
 811end Reference
 812end Foundation
 813end IndisputableMonolith
 814

source mirrored from github.com/jonwashburn/shape-of-logic