Technical Lean evidence record
Checked Artifact: Myhill–Nerode Theorem (mathlib)
Proof Atlas collected build, no-sorry, axiom, and clean-source evidence directly from the pinned upstream declaration.
ProofAtlas record
What has been checked
These states distinguish upstream identity, local reproduction, review, and Atlas acceptance. This page is part of the public, read-only Mathlib landmark collection.
Mechanical evidence
- Declaration checked
Language.isRegular_iff_finite_range_leftQuotient- Module
Mathlib.Computability.MyhillNerode- Source file checked
Mathlib/Computability/MyhillNerode.lean- Package commit
5e932f97dd25535344f80f9dd8da3aab83df0fe6- Build
- passed · transcript retained
- Unfinished proof steps
- None found by the recorded no-sorry scan
- Axiom closure
- Classical.choice, Quot.sound, propext
- Clean collection provenance
- Recorded
Evidence boundary
This target indexes Mathlib's left-quotient formulation of the Myhill–Nerode theorem. For a language L, leftQuotient sends a word x to the language of suffixes y such that x ++ y ∈ L. The theorem identifies regularity of L with finiteness of the range of that function. It does not, in this declaration, assert uniqueness of a minimal DFA, state finite index of the Nerode equivalence, or derive the pumping lemma.
This checker record is evidence for the exact formal statement only. It does not establish novelty, transfer a historical acceptance decision, or authorize publication.