Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
- Let be natural numbers with . Let be an open subset of Euclidean space , and let . We say that is of class on if for every multi-index of length with order and every…
Smooth Inverse Function Theorem on Euclidean Open Sets
theoremthm:smooth-local-inverse-euclidean-2026bLet be a natural number, let be an open subset of Euclidean space , and let be a smooth map. Let , and suppose that the Jacobian determinant satisfies . Then there exist open sets with…Inverse Function Theorem for Maps on Euclidean Open Sets
theoremthm:inverse-function-c1-euclidean-open-set-2026bLet be a natural number, let be an open subset of Euclidean space , and let be a map. Let , and suppose that the Jacobian determinant satisfies . Then is a local diffeomorphism at .Local Diffeomorphism on a Euclidean Open Set
definitiondef:locally-invertible-c1-map-euclidean-open-set-2026bLet be a natural number, let be an open subset of Euclidean space , and let be a map. Let . We say that is a local diffeomorphism at if there exist open sets with …- Let be natural numbers. Let be an real matrix, let be an real matrix, and let be a real matrix, with all products taken in the sense of the matrix product definition. Then
- Let be a natural number, and let be an invertible real matrix. Then the inverse of is unique.
- Let be a metric space, and let be a sequence in . We say that is a Cauchy sequence in if for every real number there exists such that for every…
Convergent Sequence in a Metric Space
definitiondef:convergent-sequence-metric-space-2026aAnalysisTopologyLet be a metric space, let be a sequence in , and let . We say that converges to in the metric space if for every real number there exists such that for eve…- Let be a set. A sequence in is a family indexed by the natural numbers such that for every .
Contraction Mapping Theorem on a Nonempty Complete Metric Space
theoremthm:contraction-mapping-complete-metric-space-2026bAnalysisTopologyLet be a complete metric space, and suppose that is nonempty. Let be a contraction. Then has a unique fixed point in . Moreover, for every , the iterated sequence converges to that fixed…- Let be a metric space, and let be a map. We say that is a contraction if there exists a real number satisfying such that for every .
- Let be a set, and let be a map. A point is called a fixed point of if
- Let be a metric space. We say that is complete if every Cauchy sequence in converges to a point of .
Inverse Matrix and Invertible Real Square Matrix
definitiondef:inverse-matrix-invertible-real-square-matrix-2026aLinear AlgebraLet , and let and be real matrices. We say that is an inverse of if where matrix multiplication is the product from the matrix product definition and is the identity matrix from…- Let . The identity matrix of size is the real matrix where
Orientable and Oriented Smooth Manifold with Boundary
definitiondef:oriented-smooth-manifold-boundary-2026aTopologyGeometryLet 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-2026aTopologyGeometryLet 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-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…