Claude-constructed ring separates left and right PCI and V-domain properties

The paper and Lean theorem give a countable domain R that is a left PCI ring and left V-ring but is neither right Ore, right PCI nor right V. Its opposite ring is therefore a right PCI ring that is not left PCI, and R is a left V-domain that is not a right V-domain.

Sources for this record

What was already known

Faith, Cozzens and Faith, and Damiano had left open whether every right PCI ring is left PCI. Cozzens and Faith also asked whether a left V-domain must be right V; earlier symmetry implications required extra Ore or Noetherian hypotheses.

AI involvement AI-led

The author says Claude models produced the mathematical construction, manuscript, Lean code and metadata at his direction. His role in directing and submitting is acknowledged; the source does not document task-only autonomy.

Vlad Tsyrklevich states that Claude models produced the mathematics, manuscript and Lean code at his direction; the human reviewed the Challenge statement and submitted the project, but no human expert has checked the mathematics.

Importance Notable

Provides counterexamples to two longstanding left-right symmetry questions in noncommutative ring theory.

Limitations

The entire paper and Lean proof library were machine-written by Claude under Vlad Tsyrklevich’s direction. The project says no human expert has checked the mathematics; a human reviewed only the Challenge statement. The compared Lean theorem covers the countable-domain, PCI, V-ring and non-right-Ore properties, but does not encode the paper’s additional claims that the ring is simple, principal on the left, left Noetherian, left hereditary or specifically an Ore extension.

Technical verification Formal (Lean + comparator)

The source reports a Lean proof library, completed Solution module, and Comparator checks matching the three main existence and asymmetry statements to Challenge. The assessed claim is the compared core theorem. Additional paper properties—simple, principal left ideal, left Noetherian, left hereditary, and explicit Ore-extension form—are outside the compared statement.

Formal checking

Palomar-registered source reports Lean comparator statement/axiom checks for the three exact existence and corollary theorems; the compared scope excludes extra structural properties.

Checker
Lean 4 kernel and Comparator as reported by the source repository and Palomar registry
Scope
Existence of a countable left PCI, left V domain that is not right Ore, PCI or V, plus asymmetry corollaries
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Few

The maintainer positively states no human has checked the mathematics; only the Challenge statement was human-reviewed. No human explanation of the construction’s free-field and pseudo-linear-equation mechanism is documented.

Correction and publication history

2026-10-18 · publication

Original construction, prior open questions, AI authorship and exact compared Lean statements reviewed; non-notifying local inclusion.

Read this published revision