Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
Interior Points, Boundary Points, and Boundary of a Smooth Manifold with Boundary
definitiondef:boundary-smooth-manifold-with-boundary-2026aTopologyGeometryMultivariable CalculusLet be a smooth manifold with boundary of dimension in the sense of Smooth Atlas and Smooth Manifold with Boundary, and let . We say that is an interior point of if there exists a chart in the chosen atlas with and…Smooth Atlas and Smooth Manifold with Boundary
definitiondef:smooth-manifold-with-boundary-2026aTopologyGeometryMultivariable CalculusLet be a topological space, and let . A smooth atlas of dimension on , modeled on the closed upper half-space, is a family of charts for some set such that the follo…Smooth Compatibility of Charts Modeled on the Closed Upper Half-Space
definitiondef:smooth-compatible-charts-upper-half-space-2026aTopologyGeometryMultivariable CalculusLet be a topological space, let , and let and be charts of dimension on in the sense of Chart Modeled on the Closed Upper Half-Space. Write…Chart Modeled on the Closed Upper Half-Space
definitiondef:chart-upper-half-space-2026aTopologyGeometryMultivariable CalculusLet be a topological space, let , and let . A chart of dimension on , modeled on the closed upper half-space, is a pair with the following properties. 1. . 2. If denotes the half-space fr…Closed Upper Half-Space in Euclidean Space
definitiondef:closed-upper-half-space-euclidean-2026aTopologyGeometryMultivariable CalculusLet . In the Euclidean space , the closed upper half-space is the subset A subset is said to be open in if there exists an open subset suc…- Let , and let . Then the following are equivalent. 1. is compact in , where is regarded as a topological space through the topology determined by the Euclidean distance. 2. is closed in a…
Compact Subset of is Closed
theoremthm:compact-subset-rn-closed-2026aAnalysisTopologyMultivariable CalculusLet , and let . Assume that is compact in , where is regarded as a topological space through the topology determined by the Euclidean distance. Then is closed in .Compact Subset of is Bounded
theoremthm:compact-subset-rn-bounded-2026aAnalysisTopologyMultivariable CalculusLet , and let . Assume that is compact in , where is regarded as a topological space through the topology determined by the Euclidean distance. Then is bounded as a subset of the metric space…Closed Box in is Compact
theoremthm:closed-box-compact-rn-2026aAnalysisTopologyMultivariable CalculusLet . For each index , let satisfy , and let be the closed box determined by these endpoints. Then is compact in , where is regarded as a topological sp…Euclidean Open Box Criterion in
theoremthm:euclidean-open-box-criterion-rn-2026aTopologyMultivariable CalculusLet and let . Then is open in the Euclidean sense if and only if for every point there exists a real number such that every point satisfying…- Let . For each index , let satisfy . The subset is called the closed box in determined by the…
Euclidean Openness Agrees with Metric Openness on
theoremthm:euclidean-open-iff-metric-open-rn-2026aTopologyMultivariable CalculusLet , let , and let be the Euclidean distance on . Then is open in the Euclidean sense if and only if is open in the metric space .Euclidean Distance is a Metric on
theoremthm:euclidean-distance-is-metric-rn-2026aTopologyMultivariable CalculusLet . Then the Euclidean distance is a metric on .- Let . Consider the set appearing in the definition of open subsets of Euclidean space. For points in , define where den…
Permutation Rule for Wedge Products of Coordinate 1-Forms
theoremthm:permutation-rule-coordinate-wedge-forms-euclidean-2026aGeometryMultivariable CalculusLet , let be open, let , and let be a permutation in the sense of Permutation of the Set . Then the coordinate -forms from…Active Coordinate Coefficient Formula for the Exterior Derivative
theoremthm:active-coefficient-exterior-derivative-euclidean-2026aGeometryMultivariable CalculusLet with , let be open, let be a differential -form on , and fix strictly increasing indices Write in the coordinate expansion from…Derivative of a Coordinate Slice of a Function on a Euclidean Open Set
theoremthm:coordinate-slice-derivative-c1-euclidean-2026aAnalysisMultivariable CalculusLet , let be open, let be a map, let , and let . Let with , and assume that…Associativity of the Wedge Product of Differential Forms on Euclidean Space
theoremthm:associativity-wedge-differential-forms-euclidean-2026bGeometryMultivariable CalculusLet , let be open, let , let be a differential -form on , let be a differential -form on , and let be a differential -form on . Then…Stokes Theorem for Oriented Sub-Rectangles in Euclidean Space
theoremthm:stokes-oriented-sub-rectangles-euclidean-2026bAnalysisGeometryMultivariable CalculusLet with , let be an oriented -sub-rectangle of , let be open with , and let be a differential -form on . Then…Oriented k-Sub-Rectangle of Euclidean Space
definitiondef:oriented-k-sub-rectangle-euclidean-2026aGeometryMultivariable CalculusLet with . Choose strictly increasing indices choose real numbers for , and for each index choose a real number . Let…