Alphabeta Math
PropositionStatement: Literature-sourcedProof: AI-adaptedprecheck passjudge pass (deepseek-v4-pro + claude-opus-5[1m])audited 2026-08-24
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.

The tangent plane is invariant under regular reparametrization

Statement

Regular reparametrizations preserve the tangent plane at corresponding interior parameter points.

Precisely, if ψ=φ∘h and (s,t) is interior, then span⁡{ψs,ψt}=span⁡{φu,φv}∣h(s,t).

Facts & Assumptions

Given: A regular reparametrization ψ=φ∘h and an interior parameter point (s,t).

[L1]

The tangent plane is the span of the two parameter derivatives (The tangent plane of a regular surface patch), and a regular reparametrization is induced by a parameter diffeomorphism (Surface reparametrizations and their orientation sign).

[L2]

The chain rule gives Dψ=Dφ∘Dh, and total derivatives applied to standard basis vectors are the parameter partial derivatives (The chain rule for total derivatives: D(g∘f)(a)=Dg(f(a))∘Df(a), A total derivative computes every directional derivative, and its matrix is the Jacobian).

Proof

technique · direct
1.1givenL1L2

By [L2], each of ψs and ψt is a linear combination of φu and φv at h(s,t), so the new tangent span is contained in the old one.

2.1step 1.1L1L2

Apply the same argument to the inverse parameter diffeomorphism h−1; it expresses φu and φv as linear combinations of ψs and ψt, giving the reverse containment.

3.1step 1.1step 2.1∎

The two spans are equal. Invertibility of Dh ensures neither independent tangent pair loses rank.

Depends on

Used by

Nothing in the library uses this result yet.

Dependency tree · two levels

15 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.

Sources