Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
Measurable Reconstruction of the Controlled N-Agent Dynamics from Observation Records
lemmalem:n-agent-record-reconstruction-2026bProbabilityAdopt the setting of the controlled -agent dynamics with agents, states, observation channels, and control dimension , with a nonempty control set in Euclidean space: a transition-rate family wit…The Record-Frozen Control Path and Record-Frozen Policy
definitiondef:record-frozen-control-2026bProbabilityLet and be natural numbers, let be a real number, let be an observation-driven control policy with horizon , control dimension , and channels, and let be a member of the observation record space…The Observation Record of a Solution of the Controlled N-Agent Dynamics
definitiondef:observation-record-2026bProbabilityAdopt the setting of the controlled -agent dynamics with control dimension , and let be a nonempty subset of Euclidean space : a transition-rate family with control set and rate bound , an observation-rate family…- Let be a natural number and let be a real number. Write , whose members are called channels, and write and for the -fold Borel -algebra and product Lebesgue measure on . An…
Independence Fubini: Integration in an Independent Random Vector Given a Sub-Sigma-Algebra
lemmalem:independence-fubini-2026aAnalysisProbabilityLet be a probability space, let be a -algebra on with , let be a natural number, and let be measurable with respect to and the -fold…Cumulative-Rate Time Change: Regularity, Substitution, and Crossing Times
lemmalem:cumulative-rate-substitution-2026bAnalysisLet and be real numbers and let be measurable with respect to the trace Borel -algebra . Define the cumulative rate by the…Uniqueness of Finite Measures on a Generating Pi-System and the Density of the Exponential Law
lemmalem:finite-measure-uniqueness-2026aAnalysisProbability(Uniqueness) Let be a measurable space, let be a -system of subsets of whose generated -algebra is , and let and be measures on with and for every…- Let be a natural number and let be a real number. Write and for the -fold Borel -algebra and product Lebesgue measure on , and for the factorial. The ordered time simplex with horizon is t…
Assembly of Measure Spaces: Restriction, Transport, One-Point Spaces, and Countable Disjoint Unions
lemmalem:measure-space-assembly-2026aAnalysisMeasurability of maps between measurable spaces is that of Measurable Function and Real-Valued Measurable Function; measurability and integrals of -valued functions are those of Lebesgue Integral of a Nonnegative Measurable Function; measures use the conventions of…- Let be a probability space, let be a natural number, let be a measurable space, and let be a -finite measure on it. Let and be the -fold product -algebra and product of Lebesgu…
Finite Products of Lebesgue Measure and Coordinate Integration on
lemmalem:lebesgue-product-coordinate-integration-2026aAnalysisProbabilityLet be a natural number. Write for the Borel -algebra on the real numbers and for Lebesgue measure on it. Members of the -fold Cartesian product are written as tuples , and f…Image Measures, Measures with Densities, and Change of Variables
lemmalem:image-measure-density-2026aAnalysisProbabilityLet be a measure space and let be a measurable space. Measurability of maps between measurable spaces is that of Measurable Function and Real-Valued Measurable Function; measurability and integrals of -valued functions are those…Variational Representation and Convexity of the Matrix Inverse
lemmalem:matrix-inverse-convexity-2026aLinear AlgebraLet be a natural number. All matrices below are real matrices, combined entrywise by the matrix sum and scalar multiple; denotes the dot product on the Euclidean space , and denotes the matrix-vector product.…- A function of class is a classical solution when vanishes at its own value, gradient and Hessian at every point.
Classical Subsolution and Supersolution of a Second-Order Equation
definitiondef:classical-sub-supersolution-2026cAnalysisPDEA function of class is a classical subsolution if pointwise at its own derivatives, and a classical supersolution if .- Let be a natural number, let be an open subset of Euclidean space , let be the set of real numbers with the order of its ordered field structure, let be the…
Degenerate Elliptic Second-Order Equation Operator
definitiondef:degenerate-elliptic-operator-2026aAnalysisPDELet be a natural number, let be an open subset of Euclidean space , let be the set of real numbers with the order of its ordered field structure, let be the…Second-Order Equation Operator on a Euclidean Open Set
definitiondef:second-order-equation-operator-2026aAnalysisPDELet be a natural number, let be an open subset of Euclidean space , let be the set of real numbers, and let be the set of symmetric real matrices. We write…Gradient of a Real-Valued Function on a Euclidean Open Set
definitiondef:gradient-euclidean-open-set-2026bAnalysisMultivariable CalculusLet be a natural number, let be an open subset of Euclidean space , let be the set of real numbers, let , and let . Assume that for every the partial derivative of with respe…Monotonicity of Squaring on the Nonnegative Elements of an Ordered Field
lemmalem:squares-monotone-nonnegative-2026aAnalysisAlgebraLet together with be an ordered field, with additive identity , and for let denote the associated strict order, that is, together with . For write for . Let satisfy…