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def definition def or abbrev high

orderRealization

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The ordered integer realization supplies a concrete model of the forced arithmetic on the integers, using unit step and equality cost on the carrier. Researchers working on the universal forcing chain cite it as the base ordered model that embeds the logic natural numbers into the integers. The definition assembles the structure record by wiring integer operations to the inductive orbit and verifying invariants through direct rewriting and normalization.

claimThe ordered realization is the structure with carrier the integers $Z$, cost the natural numbers, zero element $0$, step function $z mapsto z+1$, orbit the inductive logic natural numbers, and interpretation the embedding that sends the orbit identity to $0$ and each successor to an increment by one.

background

The module introduces order-theoretic realizations that carry the arithmetic forced by logic. The logic natural numbers form an inductive type with an identity constructor and a successor constructor; this encodes the smallest orbit closed under the generator and containing the identity, as described in the upstream ArithmeticFromLogic development. The integer realization is lightweight: the certified internal orbit carries the forced arithmetic while the carrier uses the standard embedding of the orbit into the integers.

proof idea

The definition constructs the realization structure field by field, assigning the integer carrier, natural-number cost, integer successor step, logic natural orbit, and embedding interpretation. The interpret_step field is discharged by rewriting with the toNat successor lemma followed by normalization; orbit_no_confusion applies the zero-not-successor property; orbit_step_injective and orbit_induction are transferred directly from the corresponding logic natural theorems.

why it matters in Recognition Science

This definition supplies the ordered base case for the arithmetic equivalence result in the same module, which establishes that the Peano carrier of this realization is equivalent to the carrier of any other realization. It realizes the forced arithmetic on the ordered integers, connecting the logic-derived naturals to the integer line and supporting the universal forcing chain. It touches the question of how the abstract orbit embeds into concrete ordered structures.

scope and limits

formal statement (Lean)

  37def orderRealization : LogicRealization where
  38  Carrier := ℤ

proof body

Definition body.

  39  Cost := Nat
  40  zeroCost := inferInstance
  41  compare := intCost
  42  zero := 0
  43  step := fun z => z + 1
  44  Orbit := LogicNat
  45  orbitZero := LogicNat.zero
  46  orbitStep := LogicNat.succ
  47  interpret := intOrbitInterpret
  48  interpret_zero := by simp [intOrbitInterpret]
  49  interpret_step := by
  50    intro n
  51    show ((LogicNat.toNat (LogicNat.succ n) : ℤ) = (LogicNat.toNat n : ℤ) + 1)
  52    rw [LogicNat.toNat_succ]
  53    norm_num
  54  orbit_no_confusion := by
  55    intro n h
  56    exact LogicNat.zero_ne_succ n h
  57  orbit_step_injective := LogicNat.succ_injective
  58  orbit_induction := by
  59    intro P h0 hs n
  60    exact LogicNat.induction (motive := P) h0 hs n
  61  orbitEquivLogicNat := Equiv.refl LogicNat
  62  orbitEquiv_zero := rfl
  63  orbitEquiv_step := by intro n; rfl
  64  identity := intCost_self
  65  nonContradiction := intCost_symm
  66  excludedMiddle := True
  67  composition := True
  68  actionInvariant := True
  69  nontrivial := by
  70    refine ⟨1, ?_⟩
  71    simp [intCost]
  72
  73/-- Ordered realization carries the universal forced arithmetic. -/

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