Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
- Let be a natural number with and let be the real numbers, a Dedekind complete ordered field, with the order , the strict order and the quotient notation fixed there; write for the real number , which satisfies by claim 8 of…
- Let be a natural number with , let be the real numbers with the order of their ordered field structure, write to mean that and , let be the absolute value of , and let be the metric on of…
- Let be a natural number with , let be the real numbers with the order of their ordered field structure, and write to mean that and . Regard Euclidean space as a real vector space, with the sum of points and th…
Quadratic Increment Characterisation of Semiconvexity
lemmalem:semiconvex-quadratic-inequality-2026aAnalysisLet be a natural number with and let be the real numbers with the order of their ordered field structure; write for , which satisfies and therefore has a multiplicative inverse by claim 8 of…The Squared Norm of a Convex Combination of Two Points
lemmalem:norm-convex-combination-identity-2026aLinear AlgebraLet be a natural number with , let be the real numbers with the order of their ordered field structure, and for a real number write for the power . Regard Euclidean space as a real vector space, with the sum of…Mollification Converges Uniformly on Compact Subsets
theoremthm:mollification-uniform-convergence-compact-2026aAnalysisLet be a natural number with , let be the real numbers with the order of their ordered field structure, write to mean that and , write for the multiplicative inverse of , let be the absolute value of …Uniform Continuity Along a Compact Subset of the Domain
lemmalem:uniform-continuity-near-compact-2026aTopologyLet be a metric space, equipped with the collection of all subsets open in , which is a topology by The Open Subsets of a Metric Space Form a Topology. Let be the real numbers with the order of their ordered field structure, write to mean t…A Compact Subset of an Open Set Admits a Uniform Ball Radius
lemmalem:compact-in-open-positive-distance-2026aTopologyLet be a metric space, equipped with the collection of all subsets open in , which is a topology by The Open Subsets of a Metric Space Form a Topology. Let be the real numbers. Write for the closed ball in with centre and…- Let be a natural number with , let be the real numbers, and let satisfy and . Write for the multiplicative inverse of , and let powers with a natural exponent be those of…
- Let be a natural number with , let be the real numbers, let be the Euclidean norm on Euclidean space , and let be the Euclidean distance, a metric on ; by…
- Let be a natural number with , let be the real numbers, and let be the Euclidean norm on Euclidean space , which is an open subset of itself by claim 1 of Euclidean Space Is Open in Itself. Let be…
The Squared Euclidean Norm is Smooth
lemmalem:squared-norm-smooth-euclidean-2026aMultivariable CalculusLet be a natural number, let be the real numbers, and let be the Euclidean norm on Euclidean space , which is an open subset of itself by claim 1 of Euclidean Space Is Open in Itself. For write for…Euclidean Space Is Open in Itself
lemmalem:euclidean-space-open-ck-continuous-2026bMultivariable Calculusℝⁿ is an open subset of itself, and every real- or vector-valued function of class Cᵏ on an open subset U of ℝⁿ is continuous on U.The Exponential Bump Building Block is Smooth on the Real Line
lemmalem:exponential-bump-smooth-2026aAnalysisLet be the real numbers, an ordered field with order , regarded also as the Euclidean space , which is an open subset of itself by claim 1 of Polynomial Functions on the Real Line are Smooth. Write for the multiplicative inverse of…- Let be the real numbers, an ordered field; write for the multiplicative inverse of with , and for . Let be an interval and let be an interior point of ; differentiability at…
One-Dimensional Derivatives, Partial Derivatives, and Smoothness on the Real Line
lemmalem:derivative-smoothness-real-line-2026aAnalysisLet be the real numbers, regarded also as the Euclidean space . Differentiability of a function on an interval at an interior point is that of Derivative of a Real Function on an Interval, and denotes the derivative there. Then the following…The Exponential Function Dominates Every Polynomial Function
theoremthm:exponential-dominates-polynomial-2026aAnalysisLet be the real numbers, an ordered field with order , write for the absolute value of and for the multiplicative inverse of , and let be the exponential function. Let be a polynomial function on .…- Let be the real numbers, an ordered field with order , and let be the exponential function. Let be the set of natural numbers, with successor map as in that definition, let be the canonical map…
Growth Bound for a Polynomial Function on the Real Line
lemmalem:polynomial-growth-bound-real-2026aAnalysisLet be the real numbers, an ordered field with order , and write for the absolute value of . Let be the set of natural numbers, with the order also written , and let powers be the natural number powers of . Th…- Let be the real numbers, regarded as the Euclidean space , and let be a polynomial function on . Then the following hold. 1. (The whole space is open) is an open subset of .…