theorem
proved
term proof
derivation_chain_consistent
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formal statement (Lean)
184theorem derivation_chain_consistent : Nonempty DerivationChain := by
proof body
Term-mode proof.
185 constructor
186 exact {
187 has_recognition := ⟨Unit, ⟨fun _ _ => True, (), trivial⟩⟩,
188 forces_ledger := trivial,
189 forces_phi := trivial
190 }
191
192/-- φ is the unique positive solution to x² = x + 1. -/