Design of a Lean formalization slice before writing any code: the five-question compact design check, convention locks by definitional acceptance tests, the authoritative-spec principle, and the characteristic-API rules for public declarations. Slice…
Pinned-revision API reconnaissance before proposing any Lean theorem. Classifies each requirement as direct, local lemma, or infrastructure blocker against the exact pinned mathlib commit, and emits a verdict plus a manifest instead of wrapper theorems.
Run and verify a Lean project at the toolchain level: slice worktrees, safe fork rebases, pinned Lean and mathlib, cache-first builds with cache reuse, no-sorry and axiom audits, fresh-checkout reproduction, and the verification discipline for executable Lean…
Shorten Lean proofs at the mathematical interface by replacing locally rebuilt machinery with the library abstraction that already names the object. Survey the pinned revision, search by structure before writing lemmas, state at natural generality, extract…
Review for Lean and math formalization pull requests. The latest Tau Ceti rubrics are the default quality gate; the review process follows Tau Ceti coordination unless the project specifies its own rules. This skill is the extension layer on top: what the…
Bump a Lean project to a new pinned toolchain pair (Lean + mathlib + dependencies): establish the version ceiling, update the pins, resolve transitive pin conflicts, recover the cache, fix API drift against the changelog, and port tooling that elaborates…
Verify Lean proofs beyond the Lean kernel: the comparator harness with lean4export, bit-for-bit constant comparison, axiom closure, and the nanoda independent kernel, plus native-execution oracles for executable content.
Work with a formalization roadmap: layers as logical dependency structure, routes picked through the roadmap (the attack angle and the practical plan, evolving as slices accumulate), and slices as the selected next unit of work, naturally mapping to a pull…