What was already known
Ordinary interpolation results for Sacchetti’s logics and familiar depth/congruence restrictions provide the setting. The project classifies arbitrary labels rather than only one chosen congruence labeling.
AI involvement
JD Jones directed the project. GPT-6/Codex and GPT-6 Pro assisted with mathematical arguments, Lean proofs, review and verification; separate internal checks are not outside assessments.
The source attributes mathematical and formal-proof collaboration broadly; identify the retained model-origin classification idea rather than infer it from agent reviews.
Importance
Gives an exact structural criterion, with supporting positive transfers and negative obstructions, for this modal substitution/interpolation setup.
Limitations
The source atom type must be nonempty for the substitution characterization. Ordinary uniform/Lyndon/Craig interpolation properties remain explicit inputs where used; they are not proved by this project. This concerns the disclosed Hilbert calculus and labeling conventions, not arbitrary modal logics. Worldwide priority and independent human specialist review are not established. AIProofWatch read the exact challenge and disclosure but did not rebuild the proof or audit every formal definition.
Technical verification
A completed rigorous check is documented for the scoped statement. Palomar: Lean, NanoDa and con-ron (reported): The registered depth-labeling, simultaneous-substitution and structural interpolation contracts at 8c5fc2afd424a0fc593c97031ada788befdc5b10. Ordinary interpolation remains explicit; only propext, Quot.sound and Classical.choice permitted.
Formal checking
Reported checking of the stated formal scope; not reproduced by AIProofWatch. Separate kernels and author-produced checkers do not establish outside researcher review.
- Checker
- Palomar: Lean, NanoDa and con-ron (reported)
- Scope
- The registered depth-labeling, simultaneous-substitution and structural interpolation contracts at 8c5fc2afd424a0fc593c97031ada788befdc5b10. Ordinary interpolation remains explicit; only propext, Quot.sound and Classical.choice permitted.
- Basis
- Reported by the linked checker
- Check date
- 2026-10-15
Checking a formal statement does not establish that it matches the original problem.
Human understanding
Few is the default when evidence for a higher level is insufficient. No sufficient account of a named human explaining the scoped central reasoning is established in this assessment. Missing disclosure is not evidence of little understanding.
Correction and publication history
Primary statement, hypotheses, prior bounds, AI role and evidence scope reviewed on 16 October 2026 against every current catalog/update page and existing immutable revisions. New recent scoped contribution; ordinary notifying editor publication.
Read this published revision