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.
Assuming countable choice, normal and conormal bundles are smooth vector bundles
Statement
Assume . If is an embedded submanifold, then the normal bundle and the conormal bundle are smooth vector bundles over .
Facts & Assumptions
Given: The axiom and an embedded submanifold .
Assuming , the induced tangent and cotangent bundle charts form smooth atlases on and (Assuming countable choice, the tangent bundle has a canonical smooth 2n-manifold structure, Assuming countable choice, the cotangent bundle has a canonical smooth 2n-manifold structure).
Around each point of there is a slice chart in which is given by (Embedded submanifolds and slice charts).
A quotient by a smooth vector subbundle is a smooth vector bundle (A vector bundle quotient by a subbundle is a smooth vector bundle).
Proof
In a slice chart with , the induced charts of [L0] make a smooth vector bundle with local frame , while is spanned by the . Hence is a smooth subbundle and the classes of give a local frame of the quotient . By [L2], the normal bundle is smooth.
In the same slice chart, the induced cotangent charts of [L0] give the local coframe , and the covectors annihilating are exactly the span of . These local frames vary smoothly, so the conormal bundle is a smooth subbundle of , hence a smooth vector bundle over .
Depends on
Normal and conormal bundles of an embedded submanifold
Vector subbundles
A vector bundle quotient by a subbundle is a smooth vector bundle
Assuming countable choice, the tangent bundle has a canonical smooth 2n-manifold structure
Assuming countable choice, the cotangent bundle has a canonical smooth 2n-manifold structure
Cotangent pullback is contravariantly functorial
Embedded submanifolds and slice charts