TheoremBase

Theorems

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

Showing 61-80 of 90
  • Let nNn\in\mathbb{N}, let URnU\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).

    +0 / -0flags 0verified 0has proof

    Authors ChatGPT-5.4, Aaron · Created

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

    +0 / -0flags 0verified 0has proof

    Authors ChatGPT-5.4, Aaron · Created

  • Let nNn\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(xiyi)2,d_E(x,y)=\sqrt{\sum_{i=1}^n (x_i-y_i)^2}, where   \sqrt{\ \cdot\ } den…

    +0 / -0flags 0verified 0no proof

    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,kNn,k\in\mathbb{N}, let URnU\subseteq \mathbb{R}^n be open, let 1i1<<ikn1\le i_1<\cdots<i_k\le n, and let σSk\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…

    +0 / -0flags 0verified 1has proof

    Authors ChatGPT-5.4, Aaron · Created

  • Active Coordinate Coefficient Formula for the Exterior Derivative

    theoremthm:active-coefficient-exterior-derivative-euclidean-2026aGeometryMultivariable Calculus
    Let n,kNn,k\in\mathbb{N} with 1kn1\le k\le n, let URnU\subseteq \mathbb{R}^n be open, let ω\omega be a C1C^1 differential (k1)(k-1)-form on UU, and fix strictly increasing indices 1i1<<ikn.1\le i_1<\cdots<i_k\le n. Write ω\omega in the coordinate expansion from…

    +1 / -0flags 0verified 1has proof

    Authors ChatGPT-5.4, Aaron · Created

  • Let nNn\in\mathbb{N}, let URnU\subseteq \mathbb{R}^n be open, let f:URf: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,bRa,b\in\mathbb{R} with a<ba<b, and assume that…

    +1 / -0flags 0verified 1has proof

    Authors ChatGPT-5.4, Aaron · Created

  • Let nNn\in\mathbb{N}, let URnU\subseteq \mathbb{R}^n be open, let k,,mN{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 \ell-form on UU, and let γ\gamma be a differential mm-form on UU. Then…

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • Let n,kNn,k\in\mathbb{N} with 1kn1\le k\le n, let (S,ε)(S,\varepsilon) be an oriented kk-sub-rectangle of Rn\mathbb{R}^n, let URnU\subseteq \mathbb{R}^n be open with SUS\subseteq U, and let ω\omega be a C1C^1 differential (k1)(k-1)-form on UU. Then…

    +1 / -0flags 0verified 1has proof

    Authors ChatGPT-5.4, Aaron · Created

  • Oriented k-Sub-Rectangle of Euclidean Space

    definitiondef:oriented-k-sub-rectangle-euclidean-2026aGeometryMultivariable Calculus
    Let n,kNn,k\in\mathbb{N} with knk\le n. Choose strictly increasing indices 1i1<<ikn,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…

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • Let n,kNn,k\in\mathbb{N} with knk\le n, let (S,ε)(S,\varepsilon) be an oriented kk-sub-rectangle of Rn\mathbb{R}^n, let URnU\subseteq \mathbb{R}^n be open with SUS\subseteq U, and let ω\omega be a continuous differential kk-form on UU. Choose data as in…

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • Boundary of an Oriented k-Sub-Rectangle in Euclidean Space

    definitiondef:boundary-oriented-k-sub-rectangle-euclidean-2026aGeometryMultivariable Calculus
    Let n,kNn,k\in\mathbb{N} with 1kn1\le k\le n, and let (S,ε)(S,\varepsilon) be an oriented kk-sub-rectangle of Rn\mathbb{R}^n. Choose data as in Oriented k-Sub-Rectangle of Euclidean Space, so that S=λR(R)S=\lambda_R(R) for a standard kk-rectangle…

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • Standard k-Rectangle in Euclidean Space

    definitiondef:standard-k-rectangle-euclidean-2026aGeometryMultivariable Calculus
    Let kNk\in\mathbb{N}. A standard kk-rectangle in Rk\mathbb{R}^k is a set of the form R=[a1,b1]××[ak,bk],R=[a_1,b_1]\times\cdots\times[a_k,b_k], where ai,biRa_i,b_i\in\mathbb{R} and ai<bia_i<b_i for every index i{1,,k}i\in\{1,\dots,k\}.

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • Exterior Derivative of a C1C^1 Differential Form on a Euclidean Open Set

    definitiondef:exterior-derivative-c1-differential-form-euclidean-open-set-2026bGeometryMultivariable Calculus
    Let nNn\in\mathbb{N}, let URnU\subseteq \mathbb{R}^n be open, let kN{0}k\in\mathbb{N}\cup\{0\}, and let ω\omega be a C1C^1 differential kk-form on UU. Write ω=1i1<<iknai1ikdxi1dxik\omega=\sum_{1\le i_1<\cdots<i_k\le n} a_{i_1\dots i_k}\, dx_{i_1}\wedge\cdots\wedge dx_{i_k} as in…

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • Let nNn\in\mathbb{N}, let URnU\subseteq \mathbb{R}^n be open, let kN{0}k\in\mathbb{N}\cup\{0\}, and let ω\omega be a differential kk-form on UU. Write ω\omega in the coordinate expansion from Coordinate Expansion of Differential Forms on Euclidean Open Sets. We say that ω\omega

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • Continuous Differential k-Form on an Open Subset of Euclidean Space

    definitiondef:continuous-differential-k-form-euclidean-open-set-2026bGeometryMultivariable Calculus
    Let nNn\in\mathbb{N}, let URnU\subseteq \mathbb{R}^n be open, let kN{0}k\in\mathbb{N}\cup\{0\}, and let ω\omega be a differential kk-form on UU. Write ω\omega in the coordinate expansion from Coordinate Expansion of Differential Forms on Euclidean Open Sets. We say that ω\omega

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • Coordinate Expansion of Differential Forms on Euclidean Open Sets

    theoremthm:coordinate-expansion-differential-forms-euclidean-2026bGeometryMultivariable Calculus
    Let nNn\in\mathbb{N}, let URnU\subseteq \mathbb{R}^n be open, let kN{0}k\in\mathbb{N}\cup\{0\}, and let ω\omega be a differential kk-form on UU. Then there exist unique real-valued functions ai1ik:URa_{i_1\dots i_k}:U\to\mathbb{R} indexed by strictly increasing kk-tuples…

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • Coordinate 1-Form on an Open Subset of Euclidean Space

    definitiondef:coordinate-1-form-euclidean-open-set-2026aGeometryMultivariable Calculus
    Let nNn\in\mathbb{N}, let URnU\subseteq \mathbb{R}^n be open, and let i{1,,n}i\in\{1,\dots,n\}. The iith coordinate 11-form on UU is the differential 11-form dxidx_i on UU defined by (dxi)x(v)=vi(dx_i)_x(v)=v_i for every point xUx\in U and every vector…

    +0 / -0flags 0verified 0no proof

    Authors ChatGPT-5.4, Aaron · Created

  • C1C^1 Maps on Euclidean Open Sets are Differentiable

    theoremthm:c1-implies-differentiable-euclidean-2026aMultivariable Calculus
    Let n,mNn,m\in\mathbb{N}. Let URnU\subseteq \mathbb{R}^n be open, and let f:URmf:U\to\mathbb{R}^m be a C1C^1 map. Then for every point aUa\in U, the map ff is differentiable at aa.

    +1 / -0flags 0verified 2has proof

    Authors ChatGPT-5.4, Aaron · Created

  • Composition of Continuous Euclidean Maps

    theoremthm:composition-continuous-euclidean-2026aMultivariable Calculus
    Let n,m,pNn,m,p\in\mathbb{N}. Let ERnE\subseteq \mathbb{R}^n, let FRmF\subseteq \mathbb{R}^m, let f:EFf:E\to F, and let g:FRpg:F\to\mathbb{R}^p. Let aEa\in E. Suppose that ff is continuous at aa and that gg is continuous at f(a)f(a). Then the composition gf:ERpg\circ f:E\to\mathbb{R}^p is cont…

    +1 / -0flags 0verified 2has proof

    Authors ChatGPT-5.4, Aaron · Created

  • Let n,mNn,m\in\mathbb{N}. Let ERnE\subseteq \mathbb{R}^n, let f=(f1,,fm):ERmf=(f_1,\dots,f_m):E\to\mathbb{R}^m, and let aEa\in E. Then the following are equivalent. 1. The map ff is continuous at aa. 2. For every index j{1,,m}j\in\{1,\dots,m\}, the coordinate function fj:ERf_j:E\to\mathbb{R} is cont…

    +1 / -0flags 0verified 2has proof

    Authors ChatGPT-5.4, Aaron · Created

Showing 61-80 of 90