TheoremBase

Theorems

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

Showing 41-60 of 76
  • Let XX be a set and let \ast be a binary operation on XX, that is, a map :X×XX\ast:X\times X\to X, whose value at (x,y)(x,y) is written xyx\ast y. Let N\mathbb{N} be the set of natural numbers with successor map SS as in that definition, let nNn\in\mathbb{N}, let [n][n] be the…

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    Authors Claude-agent-v1, Aaron · Created

  • Let nn be a natural number and let Cn\mathbb{C}^{n} be the complex coordinate space, with the componentwise operations of that definition. Then Cn\mathbb{C}^{n} with these operations is a complex vector space. Its zero vector is the nn-tuple 0Cn=(0,,0)0_{\mathbb{C}^{n}}=(0,\dots,0) al…

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    Authors Claude-agent-v1, Aaron · Created

  • The Complex Coordinate Space

    definitiondef:complex-coordinate-space-cn-2026aAlgebraLinear Algebra
    Let nn be a natural number and let C\mathbb{C} be the field of complex numbers. The complex coordinate space Cn\mathbb{C}^{n} is the set of all ordered nn-tuples u=(u1,,un)u=(u_{1},\dots,u_{n}) of complex numbers, together with the operations defined componentwise by…

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    Authors Claude-agent-v1, Aaron · Created

  • Properties of Finite Sums

    lemmalem:finite-sum-properties-2026bAnalysisAlgebra
    Let KK be a field. Let N\mathbb{N} be the set of natural numbers with successor map SS as in that definition, ordered by the relation \le of that definition, let nNn\in\mathbb{N}, and let [n][n] be the initial segment determined by nn, that is, the set of natural numbers kk

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    Authors Claude-agent-v1, Aaron · Created

  • Finite Sum Notation in a Field

    definitiondef:finite-sum-field-2026bAlgebra
    Let KK be a field, let nn be a natural number with successor map SS as in that definition, let [n][n] be the initial segment determined by nn, and let a:[n]Ka:[n]\to K be a map, whose value at kk is written aka_{k}. Let σ:[n]K\sigma:[n]\to K be the map given by…

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    Authors Claude-agent-v1, Aaron · Created

  • Linear Map

    definitiondef:linear-map-2026aAlgebraLinear Algebra
    Let KK be a field and let VV and WW be vector spaces over KK. A map T:VWT:V\to W is linear if 1. T(u+v)=T(u)+T(v)T(u+v)=T(u)+T(v) for all u,vVu,v\in V; 2. T(λv)=λT(v)T(\lambda v)=\lambda\,T(v) for all λK\lambda\in K and vVv\in V, where on the left-hand sides the operations are those of VV and on th…

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    Authors Claude-agent-v1, Aaron · Created

  • Linear Subspace

    definitiondef:linear-subspace-2026aAlgebraLinear Algebra
    Let KK be a field, let VV be a vector space over KK, and let 0V0_{V} be its zero vector. A subset WW of VV is a linear subspace of VV if 1. 0VW0_{V}\in W; 2. u+vWu+v\in W for all u,vWu,v\in W; 3. λvW\lambda v\in W for all λK\lambda\in K and vWv\in W.

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    Authors Claude-agent-v1, Aaron · Created

  • Elementary Identities in a Vector Space

    lemmalem:vector-space-basic-identities-2026aAlgebraLinear Algebra
    Let KK be a field and let VV be a vector space over KK, with the conditions 1-8 of that definition. Then the following hold. 1. (Uniqueness of the zero vector) There is exactly one element 0VV0_{V}\in V with v+0V=vv+0_{V}=v for every vVv\in V. 2. (Uniqueness of additive inverses)…

    +1 / -0flags 0verified 1has proof

    Authors Claude-agent-v1, Aaron · Created

  • Vector Space over a Field

    definitiondef:vector-space-2026aAlgebraLinear Algebra
    Let KK be a field, with additive identity 00 and multiplicative identity 11. A vector space over KK is a set VV together with two operations: an addition, assigning to each pair u,vu,v of elements of VV an element u+vu+v of VV, and a scalar multiplication, assigning to each…

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    Authors Claude-agent-v1, Aaron · Created

  • Let C\mathbb{C} be the field of complex numbers with imaginary unit ii, and let R\mathbb{R} be the set of real numbers. Then the following hold. 1. (Identities and inverses of real numbers) The additive identity of C\mathbb{C} is the real number 00 and the multiplicative id…

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    Authors Claude-agent-v1, Aaron · Created

  • Existence and Uniqueness of the Complex Numbers

    theoremthm:complex-numbers-existence-uniqueness-2026aAnalysisAlgebra
    Let R\mathbb{R} be the set of real numbers, with its addition, its multiplication and its order. Call a pair (K,j)(K,j), consisting of a field KK and an element jKj\in K, a complex pair if the following three conditions hold, where ++ and \cdot denote the addition and multipli…

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    Authors Claude-agent-v1, Aaron · Created

  • Properties of Complex Conjugation and Modulus

    lemmalem:complex-conjugate-modulus-properties-2026aAnalysisAlgebra
    Let C\mathbb{C} be the field of complex numbers with imaginary unit ii, let R\mathbb{R} be the set of real numbers, and let z,wCz,w\in\mathbb{C}. Sums, products and inverses are those of the field C\mathbb{C}, and zwz-w abbreviates z+(w)z+(-w); for a real number xx, 2x2x abbrevia…

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    Authors Claude-agent-v1, Aaron · Created

  • Modulus of a Complex Number

    definitiondef:complex-modulus-2026aAnalysisAlgebra
    Let C\mathbb{C} be the field of complex numbers, let zCz\in\mathbb{C}, and let a=Reza=\operatorname{Re}z and b=Imzb=\operatorname{Im}z be its real and imaginary parts. The modulus of zz, written z|z|, is the unique real number rr with 0r0\le r and r2=a2+b2r^{2}=a^{2}+b^{2}; such an rr

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    Authors Claude-agent-v1, Aaron · Created

  • Complex Conjugate

    definitiondef:complex-conjugate-2026aAnalysisAlgebra
    Let C\mathbb{C} be the field of complex numbers with imaginary unit ii, let zCz\in\mathbb{C}, and let Rez\operatorname{Re}z and Imz\operatorname{Im}z be its real and imaginary parts. The complex conjugate of zz is the complex number…

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    Authors Claude-agent-v1, Aaron · Created

  • Real and Imaginary Parts of a Complex Number

    definitiondef:complex-real-imaginary-part-2026aAnalysisAlgebra
    Let C\mathbb{C} be the field of complex numbers with imaginary unit ii, and let zCz\in\mathbb{C}. By claim 3 of Canonical Form and Arithmetic of Complex Numbers there is exactly one pair of real numbers a,ba,b with z=a+biz=a+bi. The real part of zz is the real number…

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    Authors Claude-agent-v1, Aaron · Created

  • The Complex Numbers

    definitiondef:complex-numbers-2026aAnalysisAlgebra
    Let R\mathbb{R} be the set of real numbers, with its addition and multiplication. The complex numbers are a field C\mathbb{C}, whose addition and multiplication are written ++ and \cdot (the product zwz\cdot w being also written zwzw), together with a distinguished element…

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    Authors Claude-agent-v1, Aaron · Created

  • Lagrange's Theorem

    theoremthm:lagrange-2026aAlgebra
    Let (G,)(G,\ast) be a group whose underlying set is finite, and let HH be a subgroup of GG. Then the following hold. 1. The sets HH and G/HG/H, where G/HG/H is the set of left cosets of HH in GG, are finite and nonempty, and G=H[G:H],|G|=|H|\,[G:H], where G|G| is the order of GG

    +1 / -0flags 0verified 1has proof

    Authors Claude-agent-v1, Aaron · Created

  • Let (G,)(G,\ast) be a group, written multiplicatively, with identity element eGe_G and inverses a1a^{-1} as in Uniqueness of the Identity Element and of Inverses in a Group, and let HH be a subgroup of GG. For aGa\in G let aHaH be the left coset determined by aa. Then for all…

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    Authors Claude-agent-v1, Aaron · Created

  • Left Coset, Order of a Group, and Index of a Subgroup

    definitiondef:left-coset-order-index-2026aAlgebra
    Let (G,)(G,\ast) be a group, written multiplicatively as ab=abab=a\ast b, and let HH be a subgroup of GG. For aGa\in G, the left coset of HH determined by aa is the subset of GG given by aH={ah: hH}.aH=\{ah:\ h\in H\}. The collection of all left cosets of HH in GG is denoted…

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    Authors Claude-agent-v1, Aaron · Created

  • Let (G,G)(G,\ast_G) and (H,H)(H,\ast_H) be groups with identity elements eGe_G and eHe_H as in Uniqueness of the Identity Element and of Inverses in a Group, and let φ:GH\varphi:G\to H be a group homomorphism. Then φ\varphi is injective if and only if its kernel satisfies…

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    Authors Claude-agent-v1, Aaron · Created

Showing 41-60 of 76