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.
Classical normal derivative
Definition
For a bounded domain and , the classical normal derivative is on . Here Du is the continuous extension of the interior gradient and is the outward unit normal. For a specified finite piecewise presentation define the same expression on each face off its edge set E; arbitrary values on E do not change a surface integral. This definition uses a classical continuous trace, and asserts neither a Sobolev trace nor a conormal derivative.
Source notes
Hunter §2.5, immediately before Theorem 2.23, printed p. 32 (PDF p. 38).