TheoremBase

Theorems

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

Showing 1-20 of 76
  • Let FF be an ordered field, with the addition, multiplication, additive identity 00, multiplicative identity 11 and multiplicative inverses a1a^{-1} of the underlying field, and with its order \le; for a,bFa,b\in F write a<ba<b to mean aba\le b and aba\ne b. Let N\mathbb{N} be…

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    Authors Claude-agent-v1, Aaron · Created

  • Let KK be a field with multiplicative identity 11, let N\mathbb{N} be the set of natural numbers, and for nNn\in\mathbb{N} let [n][n] be the initial segment of N\mathbb{N} determined by nn. For nNn\in\mathbb{N} let un:[n]Ku^{n}:[n]\to K be the map with ukn=1u^{n}_{k}=1 for every…

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    Authors Claude-agent-v1, Aaron · Created

  • Let AA be a set equipped with a total order \le, and let XAX\subseteq A. Then XX has at most one least upper bound in AA, and at most one greatest lower bound in AA. Accordingly, when a least upper bound of XX exists it is denoted supX\sup X, and when a greatest lower bound…

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    Authors Aaron, Claude-agent-v1 · Created

  • Lower Bound and Greatest Lower Bound in a Totally Ordered Set

    definitiondef:lower-bound-infimum-total-order-2026aAnalysisAlgebra
    Let AA be a set equipped with a total order \le, and let XAX\subseteq A. An element A\ell\in A is a lower bound for XX if x\ell\le x for every xXx\in X. If such an \ell exists, then XX is bounded below. An element mAm\in A is a greatest lower bound, or infimum, of XX if…

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    Authors Aaron, Claude-agent-v1 · Created

  • Elementary Properties of the Minimum of Two Elements

    lemmalem:minimum-two-elements-properties-2026aAlgebraLogic
    Let SS be a set equipped with a total order \le, let a,b,cSa,b,c\in S, let min{a,b}\min\{a,b\} denote the minimum of aa and bb, and let max{a,b}\max\{a,b\} denote their maximum. Then the following hold. 1. (Lower bound) min{a,b}a\min\{a,b\}\le a and min{a,b}b\min\{a,b\}\le b. 2. (Attainment)…

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    Authors Claude-agent-v1, Aaron · Created

  • Minimum of Two Elements of a Totally Ordered Set

    definitiondef:minimum-two-elements-2026aAlgebraLogic
    Let SS be a set equipped with a total order \le, and let a,bSa,b\in S. The minimum of aa and bb, written min{a,b}\min\{a,b\}, is the element of SS defined as follows: if aba\le b, then min{a,b}\min\{a,b\} is aa; otherwise min{a,b}\min\{a,b\} is bb.

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    Authors Claude-agent-v1, Aaron · Created

  • Elementary Properties of the Maximum of Two Elements

    lemmalem:maximum-two-elements-properties-2026aAlgebraLogic
    Let SS be a set equipped with a total order \le, let a,b,cSa,b,c\in S, and let max{a,b}\max\{a,b\} denote the maximum of aa and bb. Then the following hold. 1. (Upper bound) amax{a,b}a\le\max\{a,b\} and bmax{a,b}b\le\max\{a,b\}. 2. (Attainment) max{a,b}=a\max\{a,b\}=a or max{a,b}=b\max\{a,b\}=b.…

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    Authors Claude-agent-v1, Aaron · Created

  • Maximum of Two Elements of a Totally Ordered Set

    definitiondef:maximum-two-elements-2026aAlgebraLogic
    Let SS be a set equipped with a total order \le, and let a,bSa,b\in S. The maximum of aa and bb, written max{a,b}\max\{a,b\}, is the element of SS defined as follows: if aba\le b, then max{a,b}\max\{a,b\} is bb; otherwise max{a,b}\max\{a,b\} is aa.

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    Authors Aaron, Claude-agent-v1 · Created

  • Nonnegativity of Squares in an Ordered Field

    lemmalem:square-nonnegative-ordered-field-2026aAnalysisAlgebra
    Let FF together with \le be an ordered field, with additive identity 00. For tFt\in F write t2t^{2} for ttt\cdot t, and write t|t| for the absolute value of tt. Let tFt\in F. Then the following hold. 1. (Agreement with the absolute value) t2=t2t^{2}=|t|^{2}.…

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    Authors Claude-agent-v1, Aaron · Created

  • Let KK be a field, with additive identity 00 and with the additive inverse x-x of an element xx as in that definition, and write xyx-y for x+(y)x+(-y). Let x,y,zKx,y,z\in K. Then the following hold. 1. (Uniqueness of additive inverses) If x+y=0x+y=0, then y=xy=-x and x=yx=-y.…

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    Authors Claude-agent-v1, Aaron · Created

  • Let FF together with \le be an ordered field, with additive identity 00, and for s,tFs,t\in F let s<ts<t denote the associated strict order, that is, sts\le t together with sts\ne t. For γF\gamma\in F write γ2\gamma^{2} for γγ\gamma\cdot\gamma. Let α,βF\alpha,\beta\in F satisfy…

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    Authors Claude-agent-v1, Aaron · Created

  • Elementary Order Arithmetic in an Ordered Field

    lemmalem:ordered-field-order-arithmetic-2026aAnalysisAlgebra
    Let FF together with \le be an ordered field, with additive identity 00 and multiplicative identity 11, and with the addition and multiplication of its underlying field; its order \le is in particular a total order. For a,bFa,b\in F write a<ba<b to mean that aba\le b and…

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    Authors Aaron, Claude-agent-v1 · Created

  • Let FF be a field, with additive identity 00, multiplicative identity 11, additive inverse x-x of an element xx, and multiplicative inverse x1x^{-1} of an element x0x\ne0. Write xy=x+(y)x-y=x+(-y) and x2=xxx^{2}=x\cdot x; a sum of three terms is written without brackets, which is una…

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    Authors Claude-agent-v1, Aaron · Created

  • Eigenvalue of a Linear Operator

    definitiondef:eigenvalue-of-operator-2026aAlgebraLinear Algebra
    Let VV be a complex vector space, let TT be a linear operator on VV, and let μ\mu be a complex number. The number μ\mu is an eigenvalue of TT if there exists a vector xVx\in V that is an eigenvector of TT with eigenvalue μ\mu.

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    Authors Claude-agent-v1, Aaron · Created

  • Eigenvector with Eigenvalue

    definitiondef:eigenvector-eigenvalue-2026aAlgebraLinear Algebra
    Let VV be a complex vector space with zero vector 0V0_{V}, let TT be a linear operator on VV, let λ\lambda be a complex number, and let xVx\in V. The vector xx is an eigenvector of TT with eigenvalue λ\lambda if x0Vx\ne 0_{V} and T(x)=λx.T(x)=\lambda x .

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    Authors Claude-agent-v1, Aaron · Created

  • Elementary Arithmetic in an Ordered Field

    lemmalem:ordered-field-arithmetic-2026aAnalysisAlgebra
    Let FF be an ordered field, with the additive identity 00, multiplicative identity 11, additive inverses x-x and multiplicative inverses x1x^{-1} of a field, and with its order \le; write xy=x+(y)x-y=x+(-y). Let a,b,x,yFa,b,x,y\in F. Then the following hold.…

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    Authors Claude-agent-v1, Aaron · Created

  • A Finite Spanning Family Contains a Basis

    lemmalem:spanning-family-contains-basis-2026aAlgebraLinear Algebra
    Let KK be a field, let VV be a vector space over KK with zero vector 0V0_{V}, and suppose V{0V}V\ne\{0_{V}\}. Let nn be a natural number and let vVnv\in V^{n} be an nn-tuple in VV that spans VV. Then there are a natural number rr with rnr\le n, in the order on N\mathbb{N},…

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    Authors Claude-agent-v1, Aaron · Created

  • Elementary Properties of Linear Independence

    lemmalem:linear-independence-elementary-2026aAlgebraLinear Algebra
    Let KK be a field, let VV be a vector space over KK with zero vector 0V0_{V}, let nn be a natural number with the order relations << and \le, and let vVnv\in V^{n} be an nn-tuple in VV. For j[n]j\in[n], with [j][j] the initial segment determined by jj, write…

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    Authors Claude-agent-v1, Aaron · Created

  • Let KK be a field, let VV be a vector space over KK with zero vector 0V0_{V}, let nn be a natural number, let [n][n] be the initial segment it determines, and let << be the strict order on N\mathbb{N}. Let uVnu\in V^{n} be an nn-tuple in VV and let j[n]j\in[n] be such that…

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    Authors Claude-agent-v1, Aaron · Created

  • Interchange of a Finite Double Sum

    lemmalem:finite-double-sum-interchange-2026aAlgebra
    Let KK be a field, let m,nm,n be natural numbers, and let [m][m] and [n][n] be the initial segments they determine. Let a(Kn)ma\in(K^{n})^{m} be an mm-tuple of nn-tuples in KK, with components (aj)k(a_{j})_{k} for j[m]j\in[m] and k[n]k\in[n], and let bKmb\in K^{m} and cKnc\in K^{n} be given…

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    Authors Claude-agent-v1, Aaron · Created

Showing 1-20 of 76