Observed arrival · 2026-11-09
SeamCert looks for the gap between Lean statements and claims
It offers a free static scan of Lean 4 statement files, checking for patterns that can make a theorem weaker or more vacuous than its intended claim.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Lean 4 theorem authors and specification reviewers
- Worth noticing
- The scan is static: it does not compile or execute files, and says generated reports—not source files—are stored for 30 days.
Field notes
The scan accepts pasted source or a local Lean file and describes its checks as static text analysis, not kernel verification. Its listed probes include custom definitions, non-Mathlib imports, contradictory hypotheses and vacuous bounds; it can also generate mutation tests for a proof to reject. The public ledger cites sources for its entries and explicitly says at least one headline claim was not replayed by SeamCert.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
$PaidCommerce or pricing visible
✦PrettyNotable craft visible
◎NicheUnusually specific use
One card from the complete issue