The Erdős–Fuchs theorem is a result in number theory concerning the distribution of prime numbers. It provides a characterization of the divisibility of numbers in the context of prime factors.
Dilworth's theorem is a result in order theory, a branch of mathematics that studies the properties of ordered sets. The theorem states that in any finite partially ordered set (poset), the size of the largest antichain (a subset of elements in which no two elements are comparable) is equal to the smallest number of chains (totally ordered subsets) that can cover the poset. In more formal terms: - Let \( P \) be a finite poset.
Baranyai's theorem is a result in combinatorial design theory, specifically within the area of finite set systems. It is named after its discoverer, Zsolt Baranyai. The theorem deals with the partitioning of a complete graph into smaller structures, namely, it provides conditions under which it is possible to partition the complete graph on a certain number of vertices into disjoint complete subgraphs of smaller sizes.
The Whitney extension theorem is a fundamental result in the field of analysis and differential geometry, concerning the extension of functions defined on a subset of a Euclidean space to the entire space while preserving certain properties.
The Unique Homomorphic Extension Theorem is a result in the field of algebra, particularly concerning rings and homomorphisms. It typically states that if you have a ring \( R \) and a subring \( S \), along with a homomorphism defined on \( S \), then there exists a unique (in the case of certain conditions) homomorphic extension of this mapping up to the whole ring \( R \).
Trudinger's theorem, often discussed in the context of variational calculus and partial differential equations, refers to a result concerning minimization problems for integral functionals that involve "non-standard" growth conditions. Specifically, it addresses the existence of solutions to certain minimization problems that contain terms with exponential growth.
The Sturm separation theorem is a fundamental result in real analysis and the theory of differential equations, particularly in the context of Sturm-Liouville problems. It deals with the properties of the roots of Sturm polynomials, which are solutions to a certain class of linear differential equations.
The Stone–Weierstrass theorem is a fundamental result in analysis that provides conditions under which a set of functions can approximate continuous functions on a compact space. It generalizes the Weierstrass approximation theorem, which specifically addresses polynomial functions. Here is a more formal statement of the theorem: Let \( X \) be a compact Hausdorff space, and let \( C(X) \) denote the space of continuous real-valued functions on \( X \).
Stahl's theorem is a result in the field of mathematics, specifically in complex analysis and the theory of analytic functions. It deals with the boundary behavior of meromorphic functions and their poles.
The Silverman-Toeplitz theorem is a result in functional analysis and operator theory concerning the convergence of certain types of series of bounded linear operators. Specifically, it addresses the behavior of a series of projections in a Hilbert space. The theorem can be stated as follows: Let \( H \) be a Hilbert space and let \( \{ P_n \} \) be a sequence of orthogonal projections in \( H \).
The Shift Theorem, often associated with the field of signal processing and control theory, provides a useful relationship between the time domain and the frequency domain of a signal. It primarily refers to how a time shift in a signal affects its Fourier transform.
Sard's theorem is a result in differential topology that pertains to the behavior of smooth functions between manifolds. Specifically, it addresses the notion of the image of a smooth function and the measure of its critical values.
The Remez inequality is a result in approximation theory that provides a bound on the deviation of a continuous function from its best approximation by a polynomial. Specifically, it relates the norm of a polynomial approximation to the maximum deviation of the approximated function over a given interval.
The Rellich–Kondrachov theorem is a significant result in functional analysis and the theory of differential equations, particularly in the context of Sobolev spaces. It essentially states conditions under which the embedding of Sobolev spaces into Lp spaces is compact.
The Rademacher–Menchov theorem is a result in the field of measure theory and functional analysis. It is particularly significant in the study of series of functions, specifically in the context of rearrangement of series in Banach spaces.
The Picard–Lindelöf theorem, also known as the Picard existence theorem or the Picard-Lindelöf theorem, is a fundamental result in the theory of ordinary differential equations (ODEs). It provides conditions under which a first-order ordinary differential equation has a unique solution in a specified interval.
The Peano existence theorem, often referred to in the context of ordinary differential equations (ODEs), is a fundamental result that provides conditions under which solutions to certain initial value problems exist.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact