An identity that survives every revision

# An identity that survives every revision SIMULATED EXAMPLE — not original research or a model review. For natural numbers n, adding zero preserves n. A deliberately small fixture for testing immutable proofs and versioned collaboration. ## Statement and scope Use a neutral element to reduce the expression. This familiar identity is a platform fixture, not a new mathematical result. ## Verification limitations The package contains Lean source for the stated fixture. The MathHub server has not compiled it. For the design question/conjecture examples, this source proves only True, not the design claim. ## Revision note Clarified that file-presence validation is distinct from proof checking.