Days

Conformance Verification (LeanGuard)

Trace-certificate checking against executable Lean reference models.

Days ships with an optional Lean-based conformance checker suite called LeanGuard. LeanGuard is meant to answer a narrow, protocol-level question:

Given a simulator-produced per-transition event trace (CSV), does every logged transition match an executable reference model?

If the trace is consistent with the model, the checker prints ACCEPT. Otherwise it prints REJECT: ... with the first failing row and a diagnostic.

This section covers:

  • Use guide: how to emit traces from Days and run the Lean checkers.
  • Design sketch: how the trace-checking pipeline is structured and how to extend it to new protocols.