DefinitionDefinition: Literature-sourcedProof: Not applicablejudge pass (gpt-5.6-terra)audited 2026-09-04
How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Critical points and critical values of a smooth function
Definition
Let be a smooth function and let .
- The point is a critical point of when (The differential of a smooth real-valued function).
- A real number is a critical value of when for some critical point .
This is the specialization of Regular and critical points and values to real-valued functions: for a map to , the empty-fibre case is still regular, so a value is critical exactly when it is attained at a critical point.