The formal loop
The formal loop closes the gap between "we computed a rigorous enclosure" and "a theorem prover agrees." It is the strongest guarantee omnibias offers — and it is deliberately narrow and honest.
The pieces
omnibias.core.proof.lean_check— the bridge.formal/omnibias-verified-kernel— a Mathlib-free Lean 4 kernel with soundZIntervalalgebra and a finite rational obligation checker (sorry-free).
What gets checked
The bridge extracts a certificate's finite, rational obligation — for
example, a spectral-gap positivity, the sign of an enclosed quantity, or an
error bound below a threshold — and emits Lean that chains the kernel's proven
soundness lemmas. It then runs lake build.
from omnibias.core.proof.lean_check import verify_with_lean
verdict = verify_with_lean(certificate)
print(verdict.theorem_prover_verified) # True only on a genuine kernel pass
The honesty guarantees
theorem_prover_verified is set only on a genuine kernel pass. It can never
be set by the certificate itself, and asserting the claim without a pass
blocks the verdict. There is no path by which a fabricated certificate earns
the flag.
- Graceful degradation. If no Lean toolchain is present, the bridge degrades
gracefully and the flag stays
False— the rest of omnibias is unaffected. - Mathlib-free by design. The kernel uses Lean 4 core only, so CI can
kernel-check it cheaply. The infinite analytic obligations (for example, the
Clay-class statements scaffolded in
formal/yang-mills-mass-gap) stay honestlysorry. We do not claim otherwise.
Why "finite and rational"?
A Lean kernel can decisively check a finite inequality over rational numbers. It cannot, in a cheap CI pass, discharge an infinite analytic theorem. omnibias therefore reduces a certificate to the finite arithmetic core that a kernel can check, and is explicit that the surrounding analytic obligations remain open.
Reading a verdict
A Verdict tells you exactly three things:
- The certified enclosure (the rigorous interval / Taylor model).
- Whether the finite obligation passed the Lean kernel
(
theorem_prover_verified). - The schema version of the certificate.
That is the complete, falsifiable statement of what was verified — and an honest boundary around what was not.