TheoremBase

Theorems

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

Showing 161-180 of 199
  • Let MM be a smooth manifold with boundary of dimension nn in the sense of Smooth Atlas and Smooth Manifold with Boundary, and let p∈Mp\in M. We say that pp is an interior point of MM if there exists a chart (U,φ)(U,\varphi) in the chosen atlas with p∈Up\in U and…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let (X,T)(X,\mathcal{T}) be a topological space, and let n∈Nn\in\mathbb{N}. A smooth atlas of dimension nn on XX, modeled on the closed upper half-space, is a family of charts A=((Uα,φα))α∈A\mathcal{A}=\bigl((U_\alpha,\varphi_\alpha)\bigr)_{\alpha\in A} for some set AA such that the follo…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let (X,T)(X,\mathcal{T}) be a topological space, let n∈Nn\in\mathbb{N}, and let (U,φ)(U,\varphi) and (V,ψ)(V,\psi) be charts of dimension nn on XX in the sense of Chart Modeled on the Closed Upper Half-Space. Write…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let (X,T)(X,\mathcal{T}) be a topological space, let n∈Nn\in\mathbb{N}, and let U⊆XU\subseteq X. A chart of dimension nn on XX, modeled on the closed upper half-space, is a pair (U,φ)(U,\varphi) with the following properties. 1. U∈TU\in\mathcal{T}. 2. If HnH^n denotes the half-space fr…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}. In the Euclidean space Rn\mathbb{R}^n, the closed upper half-space is the subset Hn={x=(x1,…,xn)∈Rn:xn≥0}.H^n=\{x=(x_1,\dots,x_n)\in\mathbb{R}^n : x_n\ge 0\}. A subset Ω⊆Hn\Omega\subseteq H^n is said to be open in HnH^n if there exists an open subset U⊆RnU\subseteq\mathbb{R}^n suc…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}, and let A⊆RnA\subseteq\mathbb{R}^n. Then the following are equivalent. 1. AA is compact in Rn\mathbb{R}^n, where Rn\mathbb{R}^n is regarded as a topological space through the topology determined by the Euclidean distance. 2. AA is closed in Rn\mathbb{R}^n a…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}, and let A⊆RnA\subseteq\mathbb{R}^n. Assume that AA is compact in Rn\mathbb{R}^n, where Rn\mathbb{R}^n is regarded as a topological space through the topology determined by the Euclidean distance. Then AA is closed in Rn\mathbb{R}^n.

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}, and let A⊆RnA\subseteq\mathbb{R}^n. Assume that AA is compact in Rn\mathbb{R}^n, where Rn\mathbb{R}^n is regarded as a topological space through the topology determined by the Euclidean distance. Then AA is bounded as a subset of the metric space…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}. For each index i∈{1,…,n}i\in\{1,\dots,n\}, let ai,bi∈Ra_i,b_i\in\mathbb{R} satisfy ai≤bia_i\le b_i, and let B⊆RnB\subseteq\mathbb{R}^n be the closed box determined by these endpoints. Then BB is compact in Rn\mathbb{R}^n, where Rn\mathbb{R}^n is regarded as a topological sp…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N} and let U⊆RnU\subseteq \mathbb{R}^n. Then UU is open in the Euclidean sense if and only if for every point x=(x1,…,xn)∈Ux=(x_1,\dots,x_n)\in U there exists a real number δ>0\delta>0 such that every point y=(y1,…,yn)∈Rny=(y_1,\dots,y_n)\in\mathbb{R}^n satisfying…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}. For each index i∈{1,…,n}i\in\{1,\dots,n\}, let ai,bi∈Ra_i,b_i\in\mathbb{R} satisfy ai≤bia_i\le b_i. The subset B={x=(x1,…,xn)∈Rn:ai≤xi≤bi for every i∈{1,…,n}}B=\{x=(x_1,\dots,x_n)\in\mathbb{R}^n : a_i\le x_i\le b_i \text{ for every } i\in\{1,\dots,n\}\} is called the closed box in Rn\mathbb{R}^n determined by the…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}, let U⊆RnU\subseteq \mathbb{R}^n, and let dEd_E be the Euclidean distance on Rn\mathbb{R}^n. Then UU is open in the Euclidean sense if and only if UU is open in the metric space (Rn,dE)(\mathbb{R}^n,d_E).

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}. Then the Euclidean distance dEd_E is a metric on Rn\mathbb{R}^n.

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}. Consider the set Rn\mathbb{R}^n appearing in the definition of open subsets of Euclidean space. For points x=(x1,…,xn),y=(y1,…,yn)x=(x_1,\dots,x_n),\qquad y=(y_1,\dots,y_n) in Rn\mathbb{R}^n, define dE(x,y)=∑i=1n(xi−yi)2,d_E(x,y)=\sqrt{\sum_{i=1}^n (x_i-y_i)^2}, where  ⋅ \sqrt{\ \cdot\ } den…

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    Authors ChatGPT-5.4, Aaron · Created

  • Permutation Rule for Wedge Products of Coordinate 1-Forms

    theoremthm:permutation-rule-coordinate-wedge-forms-euclidean-2026aGeometryMultivariable Calculus
    Let n,k∈Nn,k\in\mathbb{N}, let U⊆RnU\subseteq \mathbb{R}^n be open, let 1≤i1<⋯<ik≤n1\le i_1<\cdots<i_k\le n, and let σ∈Sk\sigma\in S_k be a permutation in the sense of Permutation of the Set {1,…,r}\{1,\dots,r\}. Then the coordinate 11-forms from…

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    Authors ChatGPT-5.4, Aaron · Created

  • Active Coordinate Coefficient Formula for the Exterior Derivative

    theoremthm:active-coefficient-exterior-derivative-euclidean-2026aGeometryMultivariable Calculus
    Let n,k∈Nn,k\in\mathbb{N} with 1≤k≤n1\le k\le n, let U⊆RnU\subseteq \mathbb{R}^n be open, let ω\omega be a C1C^1 differential (k−1)(k-1)-form on UU, and fix strictly increasing indices 1≤i1<⋯<ik≤n.1\le i_1<\cdots<i_k\le n. Write ω\omega in the coordinate expansion from…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}, let U⊆RnU\subseteq \mathbb{R}^n be open, let f:U→Rf:U\to\mathbb{R} be a C1C^1 map, let i∈{1,…,n}i\in\{1,\dots,n\}, and let x=(x1,…,xn)∈Ux=(x_1,\dots,x_n)\in U. Let a,b∈Ra,b\in\mathbb{R} with a<ba<b, and assume that…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n∈Nn\in\mathbb{N}, let U⊆RnU\subseteq \mathbb{R}^n be open, let k,ℓ,m∈N∪{0}k,\ell,m\in\mathbb{N}\cup\{0\}, let α\alpha be a differential kk-form on UU, let β\beta be a differential ℓ\ell-form on UU, and let γ\gamma be a differential mm-form on UU. Then…

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    Authors ChatGPT-5.4, Aaron · Created

  • Let n,k∈Nn,k\in\mathbb{N} with 1≤k≤n1\le k\le n, let (S,ε)(S,\varepsilon) be an oriented kk-sub-rectangle of Rn\mathbb{R}^n, let U⊆RnU\subseteq \mathbb{R}^n be open with S⊆US\subseteq U, and let ω\omega be a C1C^1 differential (k−1)(k-1)-form on UU. Then…

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    Authors ChatGPT-5.4, Aaron · Created

  • Oriented k-Sub-Rectangle of Euclidean Space

    definitiondef:oriented-k-sub-rectangle-euclidean-2026aGeometryMultivariable Calculus
    Let n,k∈Nn,k\in\mathbb{N} with k≤nk\le n. Choose strictly increasing indices 1≤i1<⋯<ik≤n,1\le i_1<\cdots<i_k\le n, choose real numbers ar<bra_r<b_r for r∈{1,…,k}r\in\{1,\dots,k\}, and for each index j∈{1,…,n}∖{i1,…,ik}j\in\{1,\dots,n\}\setminus\{i_1,\dots,i_k\} choose a real number cjc_j. Let…

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    Authors ChatGPT-5.4, Aaron · Created

Showing 161-180 of 199