Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
Induced Orientation on the Boundary of an Oriented Smooth Manifold with Boundary
definitiondef:induced-orientation-boundary-manifold-2026aTopologyGeometryMultivariable CalculusLet with , and let be an oriented smooth manifold with boundary of dimension with nonempty boundary . Equip with the smooth manifold structure of dimension from…Transition Maps of Induced Boundary Charts of an Oriented Atlas are Orientation-Preserving
lemmalem:positive-jacobian-boundary-transition-2026bTopologyGeometryMultivariable CalculusLet with , and let be an oriented smooth manifold with boundary of dimension with nonempty boundary , the orientation being given by the chosen oriented smooth atlas. Then the following hold. 1. Let and be…Boundary of a Smooth Manifold with Boundary as a Smooth Manifold of Dimension n-1
theoremthm:boundary-smooth-manifold-structure-2026aTopologyGeometryMultivariable CalculusLet with , and let be a smooth manifold with boundary of dimension whose boundary is nonempty. Give the subspace topology inherited from . Then the following hold. 1. is a closed subset of . 2. Wit…Exterior Derivative of a Smooth Differential Form on a Smooth Manifold with Boundary
definitiondef:exterior-derivative-smooth-form-manifold-boundary-2026aTopologyGeometryMultivariable CalculusLet , let be a smooth manifold with boundary of dimension with chosen smooth atlas , write , let , and let …Smooth Differential k-Form on a Smooth Manifold with Boundary
definitiondef:smooth-differential-k-form-manifold-boundary-2026bTopologyGeometryMultivariable CalculusLet , and let be a smooth manifold with boundary of dimension , with chosen smooth atlas ; for each write . Each is open in the…Existence of Smooth Bump Functions on Euclidean Space
lemmalem:smooth-bump-function-euclidean-2026aAnalysisMultivariable CalculusLet , let be a point of Euclidean space , and let with . Then there exists a smooth map such that, with denoting the Euclidean distance on : 1. …Pullback Invariance of the Integral under Orientation-Preserving Smooth Diffeomorphisms
theoremthm:pullback-invariance-integral-diffeomorphism-euclidean-2026bAnalysisGeometryMultivariable CalculusLet , let be admissible domains in Euclidean space in the sense of Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain, and let be an orientation-preserving…Pullback by a Smooth Map Commutes with the Exterior Derivative
theoremthm:pullback-commutes-exterior-derivative-euclidean-2026aGeometryMultivariable CalculusLet and . Let and be open subsets of Euclidean space, let be a smooth map, and let be a differential -form on . Then the pullback is a…Smooth Diffeomorphism of Euclidean or Half-Space Domains, Jacobian, and Pullback
definitiondef:smooth-diffeomorphism-euclidean-half-space-domain-2026cGeometryMultivariable CalculusLet and let be admissible domains in Euclidean space in the sense of Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain. A smooth diffeomorphism is a bijection with the follo…Integral of a Compactly Supported Continuous n-Form on a Euclidean or Half-Space Domain
definitiondef:integral-compactly-supported-n-form-euclidean-2026aAnalysisMultivariable CalculusLet , let be an admissible domain in Euclidean space with ambient set in the sense of Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain, and let be a continuous differential -form on…Zero Extension Continuity and Box Independence of the Iterated Integral
lemmalem:zero-extension-box-integral-euclidean-2026aAnalysisMultivariable CalculusLet , let be an admissible domain in Euclidean space with ambient set in the sense of Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain, and let be a continuous differential -form on…Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain
definitiondef:continuous-n-form-support-euclidean-domain-2026cAnalysisMultivariable CalculusDefines admissible domains (open subsets of R^n or relatively open subsets of the closed upper half-space), differential n-forms on them with their coefficient functions, continuity, support, compact support, and the zero extension of the coefficient function.Stokes Theorem for Compact Oriented Smooth Manifolds with Boundary
theoremthm:stokes-smooth-manifold-boundary-2026aAnalysisTopologyGeometryMultivariable CalculusLet with , and let be an oriented smooth manifold with boundary of dimension that is compact as defined in Smooth Atlas and Smooth Manifold with Boundary. Let be a smooth differential -form on and let denote the…Positive Compatibility of Charts on the Interior of a Smooth Manifold with Boundary
definitiondef:positive-compatibility-charts-interior-manifold-boundary-2026aTopologyGeometryMultivariable CalculusLet be a smooth manifold with boundary of dimension , and let and be charts in the chosen smooth atlas. We say that these charts are positively compatible if either or else the following conditio…Jacobian Determinant of a Differentiable Map Between Euclidean Open Sets
definitiondef:jacobian-determinant-euclidean-open-set-2026aGeometryMultivariable CalculusLet , let be open, let , and let . Suppose that is differentiable at in the sense of Differentiability at a Point and Jacobian Matrix for Maps Between Euclidean Spaces, so that the Jacobian matrix…Determinant of a Real Square Matrix
definitiondef:determinant-real-square-matrix-2026aLinear AlgebraMultivariable CalculusLet , and let be an real matrix. The determinant of is the real number where is the set of permutations from…Smooth Map on an Open Subset of Euclidean Space
definitiondef:smooth-map-euclidean-open-set-2026aMultivariable CalculusLet , let be open, and let . We say that is smooth on if for every multi-index of length and every index , the partial derivative of of order exi…Partial Derivative of Order
definitiondef:partial-derivative-order-alpha-2026aMultivariable CalculusLet , let be open, let , and let be a multi-index of length . We define recursively what it means for the partial derivative of of order to exist on , and when it…Order and Factorial of a Multi-Index
definitiondef:order-factorial-multi-index-2026aCombinatoricsMultivariable CalculusLet , and let be a multi-index of length in the sense of Multi-Index of Length . The order of is the nonnegative integer The factorial of is the natural number…- Let . A multi-index of length is an element That is, a multi-index of length is an ordered -tuple of nonnegative integers. The zero multi-index of length is For e…