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.
Nonconstant Boolean functions have adversary value at least one
Statement
If f is nonconstant, then . In particular the finite optimal adversary value A used by the reflection evaluator may be taken with A≥1.
Facts & Assumptions
Given: A finite nonconstant Boolean function f.
General adversary matrix and spectral bound: admissible Γ are nonzero real symmetric and vanish on equal-output pairs.
Input-mismatch masks and entrywise filtering: Δ_i marks the coordinates on which two inputs differ.
The operator norm is zero on the zero domain and otherwise is max_{||v||=1} ||Tv||: the off-diagonal two-point swap matrix has norm one.
Proof
Choose x,y∈D with f(x)≠f(y). They are distinct bit strings, so x_i≠y_i for at least one i. Set Γ_{xy}=Γ_{yx}=1 and every other entry to zero. This Γ is nonzero and real symmetric; its only nonzero entries join opposite outputs, so Γ∘F=0.
The restriction of Γ to span{|x⟩,|y⟩} is [[0,1],[1,0]], whose eigenvalues are ±1; hence ||Γ||=1. For every i, Γ∘Δ_i is either Γ or zero, and at least one differing coordinate gives Γ itself. Thus max_i||Γ∘Δ_i||=1 and the ratio is one.
Depends on
Used by
Dependency tree · two levels
6 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
- Andrew M. Childs, Lecture Notes on Quantum Algorithms (17 April 2025) (standard reference, not scraped)
- Ronald de Wolf, Quantum Computing: Lecture Notes, arXiv:1907.09415v6 (standard reference, not scraped)