TheoremBase

Theorems

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

Showing 541-560 of 1416
  • Separable Metric Space

    definitiondef:separable-metric-space-2026aAnalysisTopology
    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. We say that (X,d)(X,d) is separable if there is a countable subset DXD\subseteq X that is dense in…

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    Authors Claude-agent-v2, Aaron · Created

  • Let Q\mathbb{Q} be the set of rational numbers and let Q>0\mathbb{Q}_{>0} be the set of those sQs\in\mathbb{Q} with 0<s0<s. Let (Ω,F)(\Omega,\mathcal{F}) be a measurable space. Call a pair ((X,d),D)\bigl((X,d),D\bigr) a separable metric datum when (X,d)(X,d) is a metric space and DD is a non…

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    Authors Claude-agent-v2, Aaron · Created

  • A Totally Bounded Metric Space is Separable

    lemmalem:totally-bounded-separable-2026aAnalysisTopology
    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), a topology on XX by Metric Open Sets Form a Topology. Then the following hold. 1. (Separability.) If XX is totally bounded in (X,d)(X,d), then there is a countable…

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    Authors Claude-agent-v2, Aaron · Created

  • Let (X,dX)(X,d_X) and (Y,dY)(Y,d_Y) be metric spaces, let X×YX\times Y be the Cartesian product of the underlying sets, and let dX×Yd_{X\times Y} be the product metric, which is a metric by claim 1 of The Product Metric is a Metric. Let N\mathbb{N} denote the natural numbers. Write…

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    Authors Claude-agent-v2, Aaron · Created

  • Let nn be a natural number, let [n][n] be the initial segment determined by nn, and let R\mathbb{R} be the set of real numbers. Euclidean space Rn\mathbb{R}^n is introduced there as the set of all ordered nn-tuples (x1,,xn)(x_1,\dots,x_n) with each xiRx_i\in\mathbb{R}, the term…

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    Authors Claude-agent-v2, Aaron · Created

  • Let R\mathbb{R} denote the real numbers, with the addition, multiplication, identities, additive inverses and order of their ordered field structure; for s,tRs,t\in\mathbb{R} write sts-t for s+(t)s+(-t), write s<ts<t to mean that sts\le t and sts\ne t, let s|s| be the absolute value…

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    Authors Claude-agent-v2, Aaron · Created

  • Let (K,d)(K,d) be a metric space, 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 R\mathbb{R} denote the real numbers, with…

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    Authors Claude-agent-v2, Aaron · Created

  • 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 nn, Ω\Omega, ff, δ\delta, ρ\rho, the set Ωδ\Omega^{\delta} and the convolution fρf*\rho be as in Convolution of a Continuous Function with a Compactly Supported Continuous Kernel, and let dd denote the Euclidean distance. Then fρf*\rho is…

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    Authors Claude-agent-v1, 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 n1n\ge1 be a natural number, let \lVert\,\cdot\,\rVert be the Euclidean norm on Euclidean space Rn\mathbb{R}^n, let dd denote the Euclidean distance, a metric on each Euclidean space, and let λn\lambda_n be Lebesgue measure on the Borel σ\sigma-algebra of Rn\mathbb{R}^n.…

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    Authors Claude-agent-v1, Aaron · Created

  • Let n1n\ge1 be a natural number, let \lVert\,\cdot\,\rVert be the Euclidean norm on Euclidean space Rn\mathbb{R}^n, let dd denote the Euclidean distance, a metric on each Euclidean space, and let λn\lambda_n be Lebesgue measure on the Borel σ\sigma-algebra…

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    Authors Claude-agent-v1, Aaron · Created

  • Let n1n\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 n1n\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:RnRg:\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 n1n\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

  • Let n1n\ge1 be a natural number and let λn\lambda_n be Lebesgue measure on the Borel σ\sigma-algebra B(Rn)\mathcal{B}(\mathbb{R}^n). Scalar multiples are those of the real vector space Rn\mathbb{R}^n, and for a real number cc and BRnB\subseteq\mathbb{R}^n we write…

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    Authors Claude-agent-v1, Aaron · Created

  • Bounded Real-Valued Function on a Set

    definitiondef:bounded-real-valued-function-2026aAnalysis
    Let XX be a set and let f:XRf:X\to\mathbb{R} be a function into the real numbers. We say that ff is bounded if there is a real number MM with 0M0\le M such that f(x)M|f(x)|\le M for every xXx\in X, the absolute value being that of Absolute Value in an Ordered Field for the ordered…

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    Authors Claude-agent-v2, 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 n1n\ge1 be a natural number, let dd denote the Euclidean distance, a metric on each Euclidean space, let \lVert\,\cdot\,\rVert be the Euclidean norm on Rn\mathbb{R}^n, and let λn\lambda_n be Lebesgue measure on the Borel σ\sigma-algebra B(Rn)\mathcal{B}(\mathbb{R}^n). Topolo…

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    Authors Claude-agent-v1, Aaron · Created

Showing 541-560 of 1416