BMC vs Unbounded Proof Strategies: Step-by-Step Walkthrough

Step-by-step analysis walkthrough

Use this sequence when owning BMC vs Unbounded Proof Strategies in a formal review.

1. Confirm trigger reachability and non-vacuous evaluation.

2. Inspect first-cycle divergence and classify failure source.

3. Check reset/fairness/assumption interactions before editing RTL.

4. Apply smallest reversible fix in model or implementation.

5. Re-run sibling properties and cover goals for collateral impact.

6. Archive decision with owner and residual-risk statement.

Artifacts to collect

• Proof intent matrix mapping each property to BMC depth goals, unbounded targets, and escalation criteria.

• counterexample replay package

• assumption traceability matrix

• vacuity and cover dashboard snapshot

• post-fix closure trend report

Decision memo template

FORMAL DECISION MEMO - BMC vs Unbounded Proof Strategies
symptom:
classification:
root cause:
fix:
validation:
owners: formal verification owner, microarchitecture owner, verification lead, quality/signoff owner

Formal deep dive

Convergence requires engine strategy, invariant quality, and model realism to move together with measurable progress.

Concept diagram

CONVERGENCE DECISION FLOW

property bucket -> engine strategy -> helper invariants -> convergence audit -> closure

Metric graph

CONVERGENCE BURNDOWN

open hard properties    ███████
inconclusive aging      █████
closed with audit       ████████

Metrics and artifacts to collect

• engine effectiveness by property class

• induction and helper-lemma success ratio

• stalled-property aging dashboard

• runtime vs closure-quality movement

Mini case study

A stalled set closed only after case-splitting by mode and auditing fairness assumptions for realism.

Debug branches

• Bucket properties by structure and intent before tuning.

• Inspect proof core stability, not runtime alone.

• Reject speed gains that reduce legal reachability.

Senior review question

Ask: which requirement intent is proven, under which assumptions, and what residual risk remains?

Key takeaways

• Tie each proof claim to assumption boundaries and reachability evidence.

• Prefer minimal reversible fixes and preserve legal behavior visibility.

Common pitfalls

• Treating runtime reduction as proof-quality improvement without audits.

• Declaring closure while critical covers remain unreachable.

• Using broad waivers instead of first-divergence root-cause ownership.

Principal formal review addendum

BMC vs Unbounded Proof Strategies should be reviewed as a requirement-evidence workflow, not a single status report.

Use Bound depth achieved, k-induction success rate, and ratio of bug-find to full-proof properties. as the monitoring lens and Proof intent matrix mapping each property to BMC depth goals, unbounded targets, and escalation criteria. as closure proof.

Convergence is an engineering loop: classify hard properties, tune engines, strengthen invariants, and audit constraints continuously. Strong teams preserve legal reachability while improving convergence.