A focused proof is a type of logical reasoning and argumentation used primarily in formal settings, such as mathematics or computer science, to establish the validity of a statement or the correctness of a program. The concept emphasizes clarity and direct relevance, ensuring that each step of the proof contributes meaningfully to the conclusion without extraneous information.
"LowerUnits" is not a specific term or concept that is widely recognized or defined in general knowledge or popular culture as of my last update in October 2023. It could refer to one of several things depending on the context—such as a technical term in a specific industry, a component of a software application, or even a nickname for a product or service.
Peano–Russell notation, also known as the Peano-Russell system or Russell's notation, is a formal language developed in logic and mathematics, primarily associated with the work of Giuseppe Peano and Bertrand Russell. This notation is intended to express mathematical concepts, particularly in the context of set theory and the foundations of mathematics, using symbols and a structured format. ### General Features 1.
Resolution proof reduction via local context rewriting is a method used in automated theorem proving and logic reasoning that involves simplifying or reducing proofs in propositional logic or predicate logic. This approach typically aims to improve the efficiency of proof search or to generate more compact proofs by leveraging the concept of local context and rewriting rules. Here's a breakdown of the key components of this method: 1. **Resolution**: This is a rule of inference used in propositional and first-order logic.
Sequent calculus is a formal system that is used in mathematical logic and proof theory. Developed by Gerhard Gentzen in the 1930s, it provides a framework for representing and manipulating logical arguments through sequences, known as sequents.
An **orthocompact space** is a concept in topology that generalizes certain properties of compact spaces. A topological space \( X \) is defined to be orthocompact if every open cover of \( X \) has a certain "sufficient" refinement property.
An **H-closed space** is a concept from topology, typically used in the study of general topological spaces. A topological space \( X \) is said to be **H-closed** if every open cover of \( X \) has a finite subcover, but only if every totally bounded subset of \( X \) is relatively compact. In simpler terms, H-closed spaces are spaces where every continuous map from a compact space into \( X \) is closed.
A **hemicompact space** is a type of topological space that is defined based on the properties of its open cover. Specifically, a topological space \( X \) is called hemicompact if every open cover of \( X \) has a countable subcover that is also locally finite. To unpack this a little further: - **Open Cover**: A collection of open sets whose union contains the entire space \( X \).
Nikolai Aleksandrovich Kozyrev (1908-1983) was a Soviet astronomer and physicist, known primarily for his work in astrophysics and for his controversial theories on the nature of time and space. He became notable for his research on the potential for physical effects arising from the gravitational influence of celestial bodies and for his hypothesis concerning the relationship between time and physical processes.
In topology, a space is said to be **limit point compact** if every infinite subset of the space has at least one limit point.
In mathematics, particularly within the field of topology, a **topological property** is a property that is preserved under homeomorphisms. A homeomorphism is a continuous function between topological spaces that has a continuous inverse. Because of this, topological properties are often called "topological invariants." Some common examples of topological properties include: 1. **Connectedness**: A space is connected if it cannot be divided into two disjoint non-empty open sets.
An ultraconnected space is a concept in topologya branch of mathematics that studies the properties of space that are preserved under continuous transformations. A topological space \( X \) is called **ultraconnected** if it is non-empty and any two open sets in \( X \) intersect non-trivially, meaning that the intersection of any two non-empty open sets is not empty.
Harry Grindell Matthews (1886–1965) was a British inventor and entrepreneur known for his work in the field of early radio technology. He gained notoriety for developing various inventions related to radio communications and wireless technology during the early 20th century. Matthews is particularly remembered for his attempts to create devices that could transmit and receive wireless signals over long distances, including efforts to develop a wireless telephone.
Alfred Lawson was an American aviation pioneer, businessman, and inventor active in the early 20th century. He is perhaps best known for developing the Lawson Airliner, which he promoted as a revolutionary aircraft design. Lawson also founded the Lawson Aviation Corporation and was involved in various ventures throughout his career, including efforts to advance the field of aviation and promote air travel. In addition to his work in aviation, Lawson was also known for his eccentric ideas and beliefs, which sometimes garnered criticism.
As of my last knowledge update in October 2023, I don't have any specific information on "Arthur Patschke." It’s possible that he is not a widely known public figure or his relevance may be limited to specific fields or locales.
The "Gunslinger effect" typically refers to a phenomenon observed in competitive environments, particularly in fields like sports or gaming, where individuals or teams make aggressive decisions or take high-risk actions in response to pressure or to compensate for perceived shortcomings. This term can also appear in contexts like trading or investments, where participants might overreach or take bold risks after a series of losses or failures.
Stefan Marinov was a Bulgarian-born physicist and entrepreneur known for his work in the fields of gravitational physics and alternative energy. Born in 1933, he emigrated to the United States where he became involved in various scientific endeavors. Marinov is perhaps best known for his controversial claims regarding the nature of gravity and his experiments aimed at demonstrating the effects of gravitational waves.
Psychoacoustics is the study of the psychological and physiological responses associated with sound. It explores how humans perceive, interpret, and react to various aspects of sound, including pitch, loudness, timbre, and spatial location. This interdisciplinary field combines principles from psychology, acoustics, and neuroscience to understand the relationship between sound waves and human perception.
The odor detection threshold is the minimum concentration of a substance that can be detected by the human sense of smell. It is the lowest level at which a particular odor can be perceived, and it can vary widely depending on the substance, the individual's sensitivity, and environmental factors. In scientific studies, the odor detection threshold is often quantified in terms of parts per million (ppm), milligrams per cubic meter (mg/m³), or other relevant units, depending on the context.
A second-order stimulus, also known as a conditioned stimulus, refers to a stimulus that has become associated with an unconditioned stimulus through a process called second-order conditioning. In classical conditioning, an unconditioned stimulus (US) naturally elicits a response (unconditioned response, UR) without prior learning, such as food causing salivation in dogs.

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 2.
    You can publish local OurBigBook lightweight markup files to either https://OurBigBook.com or as a static website
    .
    Figure 3.
    Visual Studio Code extension installation
    .
    Figure 4.
    Visual Studio Code extension tree navigation
    .
    Figure 5.
    Web editor
    . 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.
    Video 4.
    OurBigBook Visual Studio Code extension editing and navigation demo
    . Source.
  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