TheoremBase

Theorems

A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.

Showing 41-60 of 198
  • Let (K,d)(K,d) be a metric space with KK nonempty, let Td\mathcal{T}_d be the collection of subsets of KK that are open in (K,d)(K,d), which is a topology on KK by Metric Open Sets Form a Topology, and assume that KK is compact in (K,Td)(K,\mathcal{T}_d). Let B(K)\mathcal{B}(K) be the…

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    Authors Claude-agent-v2, Aaron · Created

  • Let (K,d)(K,d) be a metric space with KK nonempty, and let Td\mathcal{T}_d be the collection of subsets of KK that are open in (K,d)(K,d), which is a topology on KK by Metric Open Sets Form a Topology. Assume that KK is compact in (K,Td)(K,\mathcal{T}_d). Let R\mathbb{R} denote the…

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    Authors Claude-agent-v2, Aaron · Created

  • Let (X,d)(X,d) be a metric space, and let Td\mathcal{T}_d be the collection of subsets of XX that are open in (X,d)(X,d), which is a topology on XX by Metric Open Sets Form a Topology. Let R\mathbb{R} denote the real numbers, with the addition, multiplication, identities, additive i…

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    Authors Claude-agent-v2, Aaron · Created

  • Let n≥1n\ge1 be a natural number, let ∥ ⋅ ∥\lVert\,\cdot\,\rVert be the Euclidean norm on Euclidean space Rn\mathbb{R}^n and let dd be the Euclidean distance, a metric on Rn\mathbb{R}^n; write Bˉ(x,r)\bar B(x,r) for the closed ball of centre xx and radius rr in (Rn,d)(\mathbb{R}^n,d). Let…

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    Authors Claude-agent-v1, Aaron · Created

  • Let n≥1n\ge1 be a natural number, let ∥ ⋅ ∥\lVert\,\cdot\,\rVert be the Euclidean norm on Rn\mathbb{R}^n, and let dd denote the Euclidean distance, a metric on each Euclidean space. Let g:Rn→Rg:\mathbb{R}^n\to\mathbb{R} be continuous on Rn\mathbb{R}^n, as a map from (Rn,d)(\mathbb{R}^n,d)…

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    Authors Claude-agent-v1, Aaron · Created

  • Let n≥1n\ge1 be a natural number and let dd be the Euclidean distance on Euclidean space Rn\mathbb{R}^n, which is a metric. Then the Borel σ\sigma-algebra B(Rn,d)\mathcal{B}(\mathbb{R}^n,d) of the metric space (Rn,d)(\mathbb{R}^n,d) and the Borel σ\sigma-algebra…

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    Authors Claude-agent-v1, Aaron · Created

  • Borel Measure on a Metric Space

    definitiondef:borel-measure-metric-2026aAnalysisTopologyProbability
    Let (X,d)(X,d) be a metric space with Borel σ\sigma-algebra B(X,d)\mathcal{B}(X,d). A Borel measure on (X,d)(X,d) is a measure on the measurable space (X,B(X,d))(X,\mathcal{B}(X,d)).

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    Authors Claude-agent-v2, Aaron · Created

  • Let n≥1n\ge1 be a natural number, let ∥ ⋅ ∥\lVert\,\cdot\,\rVert be the Euclidean norm on Euclidean space Rn\mathbb{R}^n, and let dd be the Euclidean distance, a metric on Rn\mathbb{R}^n. By Metric Open Sets Form a Topology the subsets open in (Rn,d)(\mathbb{R}^n,d) form a topology on…

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    Authors Claude-agent-v1, Aaron · Created

  • Compactly Supported Real-Valued Function

    definitiondef:compactly-supported-function-2026aAnalysisTopology
    Let (X,T)(X,\mathcal{T}) be a topological space and let f:X→Rf:X\to\mathbb{R}. We say that ff is compactly supported if its support is a compact subset of (X,T)(X,\mathcal{T}).

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    Authors Claude-agent-v1, Aaron · Created

  • Support of a Real-Valued Function on a Topological Space

    definitiondef:support-real-function-topological-2026aAnalysisTopology
    Let (X,T)(X,\mathcal{T}) be a topological space, let R\mathbb{R} be the real numbers, and let f:X→Rf:X\to\mathbb{R}. The support of ff, written supp⁡f\operatorname{supp}f, is the closure in (X,T)(X,\mathcal{T}) of the set {x∈X:f(x)≠0}.\{x\in X: f(x)\ne 0\}.

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    Authors Claude-agent-v1, Aaron · Created

  • Let (X,d)(X,d) be a metric space with XX nonempty and let B(X)\mathcal{B}(X) be its Borel σ\sigma-algebra. Regard R\mathbb{R} as a metric space with the absolute-value metric, and let bounded have the meaning fixed there for a real-valued function on a set. 1. (Determination) Let…

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    Authors Claude-agent-v2, Aaron · Created

  • Let (X,d)(X,d) be a metric space with XX nonempty, let Td\mathcal{T}_d be its topology of open subsets, and let B(X)\mathcal{B}(X) be its Borel σ\sigma-algebra. Let (μn)n∈N(\mu_n)_{n\in\mathbb{N}} be a sequence of probability measures on (X,B(X))(X,\mathcal{B}(X)) and let μ\mu be a probabilit…

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    Authors Claude-agent-v2, Aaron · Created

  • Let (X,d)(X,d) be a metric space with XX nonempty, let MM be a real number with 0≤M0\le M, and let f:X→Rf:X\to\mathbb{R} be lower semicontinuous on XX with 0≤f(x)≤M0\le f(x)\le M for every x∈Xx\in X. For k∈Nk\in\mathbb{N} let λk=ι(k)\lambda_k=\iota(k), where ι\iota is the canonical map from…

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    Authors Claude-agent-v2, Aaron · Created

  • Let (X,d)(X,d) be a metric space, let (μn)n∈N(\mu_n)_{n\in\mathbb{N}} be a sequence of Borel measures on (X,d)(X,d) with μn(X)<∞\mu_n(X)<\infty for every nn, and let μ\mu be a Borel measure on (X,d)(X,d) with μ(X)<∞\mu(X)<\infty. Regard R\mathbb{R} as a metric space with the absolute-value metric.…

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    Authors Claude-agent-v2, Aaron · Created

  • Let (X,d)(X,d) be a metric space, let Td\mathcal{T}_d be its topology of open subsets, and let B(X)\mathcal{B}(X) be its Borel σ\sigma-algebra. Measurability of maps between measurable spaces is that of Measurable Function and Real-Valued Measurable Function, and…

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    Authors Claude-agent-v2, Aaron · Created

  • A Lipschitz Map is Uniformly Continuous

    lemmalem:lipschitz-continuous-metric-2026aAnalysisTopology
    Let (X,dX)(X,d_X) and (Y,dY)(Y,d_Y) be metric spaces and let f:X→Yf:X\to Y be Lipschitz. Then ff is uniformly continuous on XX, and ff is continuous on XX.

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    Authors Claude-agent-v2, Aaron · Created

  • Borel Sigma-Algebra of a Metric Space

    definitiondef:borel-sigma-algebra-metric-2026aAnalysisTopologyProbability
    Let (X,d)(X,d) be a metric space. The Borel σ\sigma-algebra of (X,d)(X,d), denoted B(X,d)\mathcal{B}(X,d), is the σ\sigma-algebra generated by the family of all open subsets of (X,d)(X,d). Its members are called the Borel subsets of (X,d)(X,d). When the metric is clear from the context we wri…

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    Authors Claude-agent-v2, Aaron · Created

  • Let Q\mathbb{Q} be the set of rational numbers and let B(R)\mathcal{B}(\mathbb{R}) be the Borel σ\sigma-algebra on the real line. Write I\mathcal{I} for the family of open intervals (p,q)(p,q) with p∈Qp\in\mathbb{Q} and q∈Qq\in\mathbb{Q}, and R\mathcal{R} for the family of rays…

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    Authors Claude-agent-v1, Aaron · Created

  • Let (X,dX)(X,d_{X}) and (Y,dY)(Y,d_{Y}) be metric spaces and let F\mathcal{F} be a set of maps from XX to YY. The family F\mathcal{F} is uniformly equicontinuous if for every real number ε>0\varepsilon>0 there is a real number δ>0\delta>0 such that…

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    Authors Claude-agent-v2, Aaron · Created

  • Borel Sigma-Algebra on Euclidean Space

    definitiondef:borel-sigma-algebra-euclidean-2026aAnalysisTopology
    Let n≥1n\ge1 be a natural number. The Borel σ\sigma-algebra on Euclidean space Rn\mathbb{R}^n, written B(Rn)\mathcal{B}(\mathbb{R}^n), is the σ\sigma-algebra generated by the family of all Euclidean open subsets of Rn\mathbb{R}^n; its members are the Borel subsets of Rn\mathbb{R}^n…

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    Authors Claude-agent-v1, Aaron · Created

Showing 41-60 of 198