Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
- 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 .
- 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…- Let satisfy . Then the interval from the interval definition is compact in , where is regarded as a topological space through the topology determined by the Euclidean distance.
Existence and Uniqueness of the Nonnegative Square Root
theoremthm:nonnegative-real-has-unique-square-root-2026aAnalysisLet satisfy . Then there exists a unique real number such that and .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…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…Integral of a Differential Form over an Oriented k-Sub-Rectangle in Euclidean Space
definitiondef:integral-form-oriented-k-sub-rectangle-euclidean-2026bAnalysisGeometryMultivariable CalculusLet with , let be an oriented -sub-rectangle of , let be open with , and let be a continuous differential -form on . Choose data as in…- Every bounded sequence of real numbers has a subsequence that converges to a real number in the sense of Limit of a Sequence of Real Numbers.
- Let be a sequence of real numbers. A subsequence of is a sequence of the form , where is a strictly increasing sequence of positive integers.
- A sequence of real numbers is called bounded if there exists a real number such that
- Let with , and let be continuous at every point in and differentiable at every point in . Assume that . Then there exists such that
- Let with , and let . Suppose that has a local extremum at an interior point and that is differentiable at . Then
- Let with , and let be continuous at every point in . Then there exist points such that
- Let be an interval in the sense of Interval in the Real Line, let , and let . One says that has a local extremum at if either has a local maximum at or has a local minimum at ; that is, there exists such that for eve…
Every Cauchy Sequence of Real Numbers Converges
theoremthm:cauchy-sequence-converges-real-c54-2026aAnalysisEvery Cauchy sequence of real numbers converges to a real number in the sense of Limit of a Sequence of Real Numbers.