Alphabeta Math
LemmaStatement: Literature-sourcedProof: AI-adaptedPipeline-generatedprecheck passjudge pass (gpt-6.1-sol)
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.

Separately holomorphic functions vanishing on a real box are zero

Statement

Let n≥1 and let G:Cn→C be separately holomorphic: for every j and every fixed w∈Cn, the one-variable map z↦G(w1,…,wj−1,z,wj+1,…,wn) is entire on C. If there are nondegenerate intervals I1,…,In⊆R with G=0 on I1×⋯×In, then G≡0 on Cn.

Facts & Assumptions

Given: An integer n≥1, a separately holomorphic G:Cn→C, and nondegenerate intervals I1,…,In (that is, each Ij contains a nonempty open subinterval, so it has more than one point) with G=0 on I1×⋯×In.

[F1]

Identity theorem: if two functions holomorphic on a complex domain Ω⊆C agree on a set having an accumulation point in Ω, then they agree on Ω (Identity theorem for holomorphic functions).

[F2]

A function is entire when it is complex differentiable on all of C, that is, holomorphic on the domain C; a separately holomorphic G has every one-variable slice entire by hypothesis (Complex differentiability at a point, the complex derivative, holomorphic functions, and entire functions).

[F3]

If J⊆R has nonempty interior and p lies in that interior, then p is an accumulation point of J in C: some open ball (p−ε,p+ε) is contained in J, and for every neighbourhood radius r>0, p+min⁡(ε,r)/2 is a point of J different from p within that neighbourhood. Every coordinate slice of a separately holomorphic function is determined by the values it takes on such a set.

Proof

technique · induction on $n$
1.1baseF1F2F3given

Base case n=1. Here G is an entire function of one variable and vanishes on the nondegenerate interval I1. Choose p in the interior of I1; by [F3], p is an accumulation point in C of the set where G and the zero function agree, and both are entire [F2]. The identity theorem [F1] on the domain C gives G≡0.

1.2ihgivenchoose

Inductive hypothesis and setup. Assume n≥2 and that the assertion holds for n−1 variables. Choose p∈int⁡I1, which is possible because I1 is nondegenerate, and fix an arbitrary z′∈Cn−1; it remains to show G(p,z′)=0.

2.1F2givenstep 1.2

The slice in the last n−1 variables. The map z′↦G(p,z′) on Cn−1 is separately holomorphic, because each of its one-variable slices is a slice of G with all other coordinates fixed, hence entire by [F2]. It vanishes on the box I2×⋯×In, whose factors are nondegenerate, so the induction hypothesis of step 1.2 applies and gives G(p,z′)=0.

3.1step 2.1

Vanishing on a slab. The point p∈int⁡I1 in step 1.2 was chosen arbitrarily in the interior, so step 2.1 gives G=0 on int⁡I1×Cn−1.

4.1F1F2F3step 1.2step 3.1

The slice in the first variable. For the fixed z′ of step 1.2, the one-variable map w↦G(w,z′) is entire by [F2] and vanishes on the nondegenerate interval int⁡I1 by step 3.1. Its zero set therefore has the accumulation point p of [F3] inside the domain C, and [F1] gives G(w,z′)=0 for every w∈C.

5.1step 1.2step 4.1discharge-induction∎

Conclusion. Since z′∈Cn−1 was arbitrary in step 1.2, step 4.1 gives G≡0 on Cn, which discharges the induction step and completes the induction.

Depends on

Used by

Dependency tree · two levels

12 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