Alphabeta Math
CounterexampleConstruction: Literature-sourcedVerification: AI-adaptedPipeline-generatedjudge pass (gpt-6-luna)
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.

A single high-degree gate defeats the stated small-k separation

Statement refuted

For every integer k≥1 and dimension d≥1, the stated Telgarsky bound asserts that there is a function f(x)=hk3+4(x1), where h(z)=ρ(2ρ(z)−4ρ(z−1/2)), computed by a ReLU network with 2k3+8 layers, 3k3+12 computation nodes, and 4+d distinct parameters, such that for every positive integer triple t,α,β its L1([0,1]d) distance from every function in the following union is at least 1/64: functions computed in at most k computational layers by networks with at most 2k/(tαβ) gate nodes whose gates are (t,α,β)-semi-algebraic; and sums of at most t affine-threshold decision trees, each with at most 2k3/t total nodes, including leaves. Here a (t,α,β)-semi-algebraic gate is a map g:Rq→R expressible as a finite sum of polynomial pieces pj of degree at most β, each multiplied by indicators of conjunctions of signs of at most t predicate polynomials qi of degree at most α; an affine-threshold decision tree recursively branches on tests ⟨a,x⟩−b≥0 and has constant real outputs at its leaves.

Facts & Assumptions

Given: The parameters and target in the counterexample description.

[F1]

The map τ(x)=2ρ(x)−4ρ(x−1/2) maps [0,1] to itself and is 2-Lipschitz (Tent-map iterates and ReLU implementation).

[F2]

A degree-N Bernstein polynomial approximates an L-Lipschitz function on [0,1] within L/(2N) (Uniform error bound for Bernstein approximation of a Lipschitz function).

Counterexample

Take d=k=t=α=1 and β=222. The target is h5(x) on [0,1], where h(x)=ρ(2ρ(x)−4ρ(x−1/2)). A single polynomial gate of degree at most 222 can compute the Bernstein polynomial of h5 of degree 222; the gate-node cap 21/222 permits one node.

1.1givenF1F2algebra

On [0,1], h(x)=2x for x≤1/2 and h(x)=2−2x for x≥1/2, so it equals the tent map in [F1], maps the interval into itself, and is 2-Lipschitz. Thus h5 is 32-Lipschitz. For N=222, [F2] gives a degree-N polynomial PN with sup⁡[0,1]∣h5−PN∣≤32/(2N)=1/128.

2.1step 1.1algebra∎

A single gate with the constant predicate polynomial q1(z)=1, condition q1(z)≥0, and polynomial piece PN is (1,1,N)-semi-algebraic; the predicate is always true and has degree 0. Since 21/N<2, the allowed integer node count is one. The normalized Lebesgue integral on [0,1] of its error is at most 1/128<1/64, so this is a counterexample to the claimed uniform lower bound.

Depends on

Used by

Nothing in the library uses this result yet.

Dependency tree · two levels

3 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