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.
Measure zero and content zero in by countable and finite cube covers
Definition
Fix . A closed cube is a rectangle with ; its volume is . A set is null when, for every , it is covered by a sequence of closed cubes whose nonnegative volume series converges with sum at most . It has content zero when such a cover can be finite.
The series and finite sums are Series, partial sums, convergence and the sum, divergence, and the tail series and Finite sums and finite products, by recursion, and their nonnegative bounds use A series of nonnegative terms converges iff its partial sums are bounded, and then the sum is their supremum and Laws of finite sums and finite products. Both properties pass to subsets. Padding a finite cover with degenerate zero-volume cubes proves that content zero implies null. This terminology defines only cover-nullity; it does not define a measure on arbitrary sets.
Depends on
- Axis-parallel rectangles in $\mathbb{R}^m$ and their volume
- Series, partial sums, convergence and the sum, divergence, and the tail series
- A series of nonnegative terms converges iff its partial sums are bounded, and then the sum is their supremum
- Finite sums and finite products, by recursion
- Laws of finite sums and finite products
- Finite, countably infinite, countable, uncountable
- Complete ordered field (least-upper-bound property)
Used by
- A bounded function on a closed bounded interval, or on a closed nondegenerate rectangle, is Riemann integrable exactly when its discontinuity set has Lebesgue measure zero Corollary
- A property holding outside a set of elementary measure zero is exactly a property holding λ-almost everywhere Corollary
- An integrable function whose sections vanish outside finite sets has multiple integral zero Corollary
- At m=1, cube-nullity and cube-content-zero are exactly the published interval-cover notions Corollary
- Jordan content is finitely additive when the overlap has content zero Corollary
- The rational points of [0,1]² form a bounded null set that is not Jordan measurable Counterexample
- Boundary presentations adapted to a simple solid region in a coordinate direction Definition
- Null subsets of a smooth manifold Definition
- A right circular cylinder is an elementary solid region, presented by two caps and four side quarters Example
- The closed ball is an elementary solid region, presented by the eight spherical octants Example
- The closed unit box, with its six faces, is an elementary solid region Example
- The parabola segment {(x,x²):0≤ x≤1} has content zero in ℝ² Example
- A C¹ map sends a compact set of content zero to a set of content zero Lemma
- A finite rectangle cover admits grid control with arbitrarily small volume excess Lemma
- A Lipschitz self-map of ℝⁿ carries Lebesgue null sets to Lebesgue null sets Lemma
- A Nonempty Euclidean Open Set Is Not Null Lemma
- Additivity of the integral over finitely many Jordan pieces that fill a Jordan set up to content zero Lemma
- Analytic-boundary exhaustion of a plane domain Lemma
- C¹ local diffeomorphisms preserve null sets locally Lemma
- Change of variables for a C¹ map injective and regular only on the interior of a compact Jordan set Lemma
- Changing a bounded integrand on a content-zero set does not change its Riemann integral Lemma
- Compact null sections imply a compact set is null Lemma
- Countable Union of Compact Null Sets Is Null Lemma
- Critical images of Euclidean Lipschitz maps are null Lemma
- For compact subsets of ℝᵐ, measure zero and content zero coincide Lemma
- Fresnel whole-line moment from the damped complex Gaussian Lemma
- Internal faces cancel and volume integrals add when elementary solid regions are glued Lemma
- Jensen maximum principle for locally semiconvex functions Lemma
- Relative generic position for characteristic disk maps Lemma
- Riemann-integrable half-space extensions of chart coefficients Lemma
- Sard on the infinitely flat critical stratum Lemma
- Shared boundary arcs cancel when finitely many elementary regions are glued Lemma
- Subsets and countable unions of null subsets of ℝᵐ are null Lemma
- The boundary of a solid between continuous graphs over a compact Jordan base has content zero Lemma
- The product of a content-zero set and a compact interval has content zero Lemma
- The Riemann integral over a Jordan set is independent of the bounding rectangle Lemma
- Countable unions and subsets of manifold null sets are null Proposition
- The image of a lower-dimensional C¹ manifold is null Proposition
- The null-set definition is independent of the smooth atlas Proposition
- Conventions and proved scope for the Riemann integral in ℝᵐ and Jordan content Remark
…and 17 more results.
Dependency tree · two levels
39 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
- J. Lebl, Basic Analysis, Riemann Integral in Several Variables (standard reference, not scraped)
- J. Lebl, Basic Analysis, The Riemann-Lebesgue Criterion (standard reference, not scraped)
- J. Lebl, Basic Analysis, Outer Measure and Null Sets (standard reference, not scraped)