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PFORGE

Lean spine source

Declarations: forgeability_gap

From the machine-checked spine in formal/ (Mathlib + spine imports). Not self-contained for Lean 4 Web — use the repo or a local lake build.

theorem forgeability_gap (δ : Int) :
    ∃ s : ForgeabilityToySuccessor,
      ForgeabilityToyAllSevenGreen s ∧
      ForgeabilityToyRiskBounded s δ ∧
      ¬ ForgeabilityToyTrueHarmBounded s δ :=
  ⟨⟨δ, δ + 1⟩, trivial, le_refl δ, by show ¬ δ + 1 ≤ δ; omega⟩