Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
Pythagorean Theorem in Euclidean Space
theoremthm:pythagorean-theorem-rn-2026aGeometryMultivariable CalculusLet , and let , , be points of Euclidean space . Assume that the differences and are orthogonal, that is, Then, with denoting the Euclidean distance on ,…Difference, Dot Product, and Orthogonality in
definitiondef:dot-product-orthogonality-rn-2026aGeometryMultivariable CalculusLet , and let and be points of Euclidean space . 1. The difference is the point of defined by where in each coordinate the difference is that of real…Integral of a Smooth n-Form over a Compact Oriented Smooth Manifold with Boundary
definitiondef:integral-form-oriented-manifold-boundary-2026aAnalysisGeometryMultivariable CalculusLet and let be an oriented smooth manifold with boundary of dimension that is compact in the sense of Smooth Atlas and Smooth Manifold with Boundary, with chosen oriented smooth atlas , and write…Independence of the Manifold Integral from Chart and Partition Choices
theoremthm:integral-manifold-independence-choices-2026aAnalysisGeometryMultivariable CalculusLet and let be an oriented smooth manifold with boundary of dimension that is compact in the sense of Smooth Atlas and Smooth Manifold with Boundary, with chosen oriented smooth atlas , and write…Smooth Partitions of Unity on a Compact Smooth Manifold with Boundary
theoremthm:smooth-partition-unity-compact-manifold-boundary-2026aAnalysisGeometryTopologyLet be a smooth manifold with boundary that is compact in the sense of that definition, with chosen smooth atlas . Then there exist , indices , and smooth differential -forms…Restriction of a Smooth Differential Form to the Boundary
definitiondef:restriction-form-boundary-manifold-2026aGeometryTopologyMultivariable CalculusLet with , let be a smooth manifold with boundary of dimension with nonempty boundary , and equip with the smooth manifold structure of dimension from…Induced Orientation on the Boundary of an Oriented Smooth Manifold with Boundary
definitiondef:induced-orientation-boundary-manifold-2026aGeometryTopologyMultivariable 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-2026aGeometryTopologyMultivariable 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-2026aGeometryTopologyMultivariable 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-2026aGeometryTopologyMultivariable 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-2026aGeometryTopologyMultivariable CalculusLet , and let be a smooth manifold with boundary of dimension , with chosen smooth atlas ; for each write . Each is open in the…Pullback Invariance of the Integral under Orientation-Preserving Smooth Diffeomorphisms
theoremthm:pullback-invariance-integral-diffeomorphism-euclidean-2026aAnalysisGeometryMultivariable 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-2026bGeometryMultivariable 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…Stokes Theorem for Compact Oriented Smooth Manifolds with Boundary
theoremthm:stokes-smooth-manifold-boundary-2026aAnalysisGeometryTopologyMultivariable 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…Orientable and Oriented Smooth Manifold with Boundary
definitiondef:oriented-smooth-manifold-boundary-2026aGeometryTopologyLet be a smooth manifold with boundary. We say that is orientable if it admits an oriented smooth atlas in the sense of Oriented Smooth Atlas on a Smooth Manifold with Boundary. An oriented smooth manifold with boundary is a smooth manifold with boundary together with a…Oriented Smooth Atlas on a Smooth Manifold with Boundary
definitiondef:oriented-smooth-atlas-manifold-boundary-2026aGeometryTopologyLet be a smooth manifold with boundary. An oriented smooth atlas on is a smooth atlas such that for every , the charts and are po…Positive Compatibility of Charts on the Interior of a Smooth Manifold with Boundary
definitiondef:positive-compatibility-charts-interior-manifold-boundary-2026aGeometryTopologyMultivariable 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…Interior Points, Boundary Points, and Boundary of a Smooth Manifold with Boundary
definitiondef:boundary-smooth-manifold-with-boundary-2026aGeometryTopologyMultivariable 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…