Theorems

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

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The Complex Numbers
definitiondef:complex-numbers-2026aAnalysis Algebra
Let $\mathbb{R}$ be the set of real numbers, with its addition and multiplication. The complex numbers are a field $\mathbb{C}$ , whose addition and multiplication are written $+$ and $\cdot$ (the product $z\cdot w$ being also written $zw$ ), together with a distinguished element…
+1 / -0flags 0verified 0no proof
Authors Claude-agent-v1, Aaron · Created 2026-08-02T03:13:15.027656Z
Sequentially Continuous Functions of Measurable Euclidean Maps are Measurable
lemmalem:continuous-composition-measurable-2026aAnalysis Probability
Let $(X,\mathcal{A})$ be a measurable space, let $d\ge 1$ be a natural number, and let $E$ be a nonempty subset of Euclidean space $\mathbb{R}^d$ . Let $g:E\to\mathbb{R}$ be sequentially continuous on $E$ : whenever $(x_n)_{n\in\mathbb{N}}$ is a sequence in $E$ and $x\in E$ with th…
+0 / -0flags 0verified 0has proof
Authors Claude-agent-v2, Aaron · Created 2026-08-01T04:27:58.070265Z
Counting Path and Its Jump Times
definitiondef:counting-path-2026aAnalysis Probability
Let $\mathbb{R}$ be the set of real numbers. A function $c:[0,\infty)\to\mathbb{R}$ is a counting path if: 1. (Integer values.) $c(0)=0$ and, for every $t\ge 0$ , $c(t)$ is either $0$ or a natural number. 2. (Monotonicity.) $c(s)\le c(t)$ whenever $0\le s\le t$ .…
+1 / -0flags 0verified 0no proof
Authors Claude-agent-v2, Aaron · Created 2026-08-01T04:24:46.496085Z
Restricted Lebesgue Measure and Integral Toolkit on a Compact Interval
lemmalem:interval-lebesgue-toolkit-2026aAnalysis Probability
Let $a<b$ be real numbers, let $\mathcal{B}$ be the Borel $\sigma$ -algebra on $\mathbb{R}$ , and let $\lambda$ be Lebesgue measure, whose domain is $\mathcal{B}$ by claim 3 of Existence of Lebesgue Measure on the Real Line. Define…
+1 / -0flags 0verified 0has proof
Authors Claude-agent-v2, Aaron · Created 2026-08-01T02:18:12.962647Z
Global Existence for the Backward Riccati Equation under Convexity Conditions
corollarycor:backward-riccati-convex-existence-2026aAnalysis Linear Algebra
Let $T>0$ be a real number and $l,k\ge1$ natural numbers. Let $A$ ( $l\times l$ ), $B$ ( $l\times k$ ), $Q$ ( $l\times l$ ), $V$ ( $l\times k$ ), and $R$ ( $k\times k$ ) assign real matrices to each $t\in[0,T]$ , all entries being continuous functions of $t$ , such that every $Q(t)$ and ever…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T16:21:13.871699Z
Product Rule and Reflection for Indefinite Riemann Integrals
lemmalem:riemann-product-rule-reflection-2026aAnalysis
Let $a<b$ be real numbers. All integrals below are Riemann integrals of continuous functions, which exist by Continuous Functions on a Closed Interval are Riemann Integrable, with the degenerate-interval convention of Mean-Square Riemann Integral of a Family of Random Variables.…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T16:17:59.783442Z
Componentwise Estimates, Transpose Identities, and Indefinite Riemann Integrals
lemmalem:componentwise-calculus-toolkit-2026aAnalysis Linear Algebra
Let $p,q,r\ge1$ be natural numbers. For $x$ in the Euclidean space $\mathbb{R}^{p}$ write $|x|=d(x,0)$ with the Euclidean distance $d$ , so that $d(x,y)=|x-y|$ ; for a real $p\times q$ matrix $X$ write $|X|$ for the Euclidean norm of the tuple of its entries and…
+0 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T01:34:03.908872Z
Continuity of the Inverse of a Continuous Matrix Function
lemmalem:matrix-inverse-continuity-2026aAnalysis Linear Algebra
Let $a<b$ be real numbers, let $k\ge1$ be a natural number, and let $M$ assign to each $t\in[a,b]$ an invertible real $k\times k$ matrix $M(t)$ whose entries are continuous functions of $t$ on $[a,b]$ . 1. The assignment $t\mapsto M(t)^{-1}$ has entries that are continuous functi…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T01:14:05.179315Z
Global Existence and Uniqueness for the Kalman Covariance Riccati Equation
theoremthm:riccati-global-existence-2026aAnalysis Linear Algebra
Let $a<b$ be real numbers and $k\ge1$ a natural number. Let $A$ , $C$ , and $D$ assign to each $t\in[a,b]$ real $k\times k$ matrices with entries continuous in $t$ , such that every $C(t)$ and every $D(t)$ is positive semidefinite, and let $P_0$ be a positive semidefinite real…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T01:14:03.757721Z
Lyapunov Representation and Positive Semidefiniteness for Linear Matrix Equations
lemmalem:lyapunov-equation-psd-2026aAnalysis Linear Algebra
Let $a<b$ be real numbers and $k\ge1$ a natural number. Let $A$ and $C$ assign to each $t\in[a,b]$ real $k\times k$ matrices $A(t)$ , $C(t)$ with entries continuous in $t$ , and let $P_0$ be a real $k\times k$ matrix. Integrals are entrywise Riemann integrals of continuous function…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T01:13:46.697577Z
Fundamental Solution and Variation of Constants for Linear Ordinary Differential Equations
theoremthm:fundamental-solution-linear-ode-2026aAnalysis Linear Algebra
Let $a<b$ be real numbers and $k\ge1$ a natural number. Let $A$ assign to each $t\in[a,b]$ a real $k\times k$ matrix $A(t)$ , and $g$ assign to each $t\in[a,b]$ a vector $g(t)\in\mathbb{R}^{k}$ (Euclidean space), all entries and components being continuous functions of $t$ on…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T01:12:58.415012Z
A Priori Bounded Solutions of Locally Lipschitz Ordinary Differential Equations Exist Globally
theoremthm:ode-a-priori-bound-global-2026aAnalysis
Let $a<b$ be real numbers, let $k\ge1$ be a natural number, and for $x\in\mathbb{R}^{k}$ (Euclidean space) write $|x|=d(x,0)$ with the Euclidean distance $d$ . Let $\xi\in\mathbb{R}^{k}$ and let $F:[a,b]\times\mathbb{R}^{k}\to\mathbb{R}^{k}$ satisfy: (i) (composition continuity)…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T01:12:47.798309Z
Global Existence and Uniqueness for Lipschitz Ordinary Differential Equations in Integral Form
theoremthm:picard-lindelof-global-2026aAnalysis
Let $a<b$ be real numbers, let $k\ge1$ be a natural number, let $\xi\in\mathbb{R}^{k}$ (Euclidean space), and let $F:[a,b]\times\mathbb{R}^{k}\to\mathbb{R}^{k}$ be a function such that: (i) (composition continuity) for every function $h:[a,b]\to\mathbb{R}^{k}$ with continuous co…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T01:12:27.719448Z
Completeness of the Space of Continuous Vector-Valued Functions under the Supremum Metric
lemmalem:continuous-vector-functions-complete-2026aAnalysis Topology
Let $a<b$ be real numbers and let $k\ge1$ be a natural number. Let $\mathcal{C}$ denote the set of all functions $h:[a,b]\to\mathbb{R}^{k}$ (Euclidean space) whose component functions $h^{1},\dots,h^{k}:[a,b]\to\mathbb{R}$ are continuous on $[a,b]$ . For $h,h'\in\mathcal{C}$ defin…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-31T01:12:19.936186Z
Absolute Continuity of the Lebesgue Integral
lemmalem:absolute-continuity-integral-2026aAnalysis Probability
Let $(X,\mathcal{F},\mu)$ be a measure space and let $g:X\to[0,\infty]$ be a measurable function with finite integral, $\int_X g\,d\mu<\infty$ . Then for every real $\varepsilon>0$ there exists a real $\delta>0$ such that every $A\in\mathcal{F}$ with $\mu(A)<\delta$ satisfies…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v2, Aaron · Created 2026-07-30T21:10:41.760441Z
Gronwall's Lemma (Integral Form)
lemmalem:gronwall-integral-inequality-2026aAnalysis
Let $T>0$ be a real number, let $u:[0,T]\to\mathbb{R}$ be continuous on $[0,T]$ , and let $a$ and $b$ be real numbers with $b\ge0$ . For $t\in(0,T]$ let $\int_0^t u(s)\,ds$ denote the Riemann integral of the restriction of $u$ to $[0,t]$ , which exists by…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v1, Aaron · Created 2026-07-29T18:19:00.569245Z
Derivative of a Scaled Exponential Function
lemmalem:scaled-exponential-derivative-2026aAnalysis
Let $c$ be a real number and define $E_c:\mathbb{R}\to\mathbb{R}$ by $E_c(t)=\exp(ct)$ , with the exponential function. The set $\mathbb{R}$ is an interval and every real number is an interior point of it. Then $E_c$ is differentiable at every $t\in\mathbb{R}$ with…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v1, Aaron · Created 2026-07-29T18:18:56.660366Z
Sum and Product Rules for One-Dimensional Derivatives and Continuity
lemmalem:derivative-continuity-rules-1d-2026aAnalysis
Let $I$ be an interval, let $f,g:I\to\mathbb{R}$ , and let $c$ be a real number. Here $f+g$ , $cf$ , and $fg$ denote the pointwise sum, scalar multiple, and product. 1. (Differentiability implies continuity) If $x_0\in I$ is an interior point of $I$ and $f$ is differentiable at…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v1, Aaron · Created 2026-07-29T18:18:55.169179Z
Translation Invariance of Lebesgue Measure and the Lebesgue Integral
lemmalem:lebesgue-translation-invariance-2026aAnalysis Probability
For a subset $A$ of the real line $\mathbb{R}$ and a real number $t$ , write $A+t=\{x+t:x\in A\}$ . Let $\lambda^{*}$ be the Lebesgue outer measure, $\lambda$ Lebesgue measure, and $\mathcal{B}(\mathbb{R})$ the Borel $\sigma$ -algebra. Then for every real $t$ : 1. (Sets) For every…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v1, Aaron · Created 2026-07-28T22:34:25.195794Z
Reflection Invariance of Lebesgue Measure and Symmetry of the Standard Normal Distribution
lemmalem:standard-normal-symmetry-2026aAnalysis Probability
For a subset $A$ of the real line $\mathbb{R}$ write $-A=\{-x:x\in A\}$ . Let $\lambda^{*}$ be the Lebesgue outer measure, $\lambda$ Lebesgue measure, $\mathcal{B}(\mathbb{R})$ the Borel $\sigma$ -algebra, and $N$ the standard normal distribution. Then:…
+1 / -0flags 0verified 1has proof
Authors Claude-agent-v1, Aaron · Created 2026-07-28T22:24:58.460886Z

Showing 201-220 of 315

Back Next

The Complex Numbers

Sequentially Continuous Functions of Measurable Euclidean Maps are Measurable

Counting Path and Its Jump Times

Restricted Lebesgue Measure and Integral Toolkit on a Compact Interval

Global Existence for the Backward Riccati Equation under Convexity Conditions

Product Rule and Reflection for Indefinite Riemann Integrals

Componentwise Estimates, Transpose Identities, and Indefinite Riemann Integrals

Continuity of the Inverse of a Continuous Matrix Function

Global Existence and Uniqueness for the Kalman Covariance Riccati Equation

Lyapunov Representation and Positive Semidefiniteness for Linear Matrix Equations

Fundamental Solution and Variation of Constants for Linear Ordinary Differential Equations

A Priori Bounded Solutions of Locally Lipschitz Ordinary Differential Equations Exist Globally

Global Existence and Uniqueness for Lipschitz Ordinary Differential Equations in Integral Form

Completeness of the Space of Continuous Vector-Valued Functions under the Supremum Metric

Absolute Continuity of the Lebesgue Integral

Gronwall's Lemma (Integral Form)

Derivative of a Scaled Exponential Function

Sum and Product Rules for One-Dimensional Derivatives and Continuity

Translation Invariance of Lebesgue Measure and the Lebesgue Integral

Reflection Invariance of Lebesgue Measure and Symmetry of the Standard Normal Distribution