Unicode in the context of "Perpendicular symbol"

In predicate logic, an existential quantification is a type of quantifier which asserts the existence of an object with a given property. It is usually denoted by the logical operator symbol ∃, which, when used together with a predicate variable, is called an existential quantifier ("∃x" or "∃(x)" or "(∃x)"), read as "there exists", "there is at least one", or "for some". Existential quantification is distinct from universal quantification ("for all"), which asserts that the property or relation holds for all members of the domain. Some sources use the term existentialization to refer to existential quantification.

Quantification in general is covered in the article on quantification (logic). The existential quantifier is encoded as U+2203 ∃ THERE EXISTS in Unicode, and as \exists in LaTeX and related formula editors.

In computing and telecommunications, a character is the encoded representation of a natural language character (including letter, numeral and punctuation), whitespace (space or tab), or a control character (controls computer hardware that consumes character-based data). A sequence of characters is called a string.

Some character encoding systems represent each character using a fixed number of bits whereas other systems use varying sizes. Various fixed-length sizes were used for now obsolete systems such as the six-bit character code, the five-bit Baudot code and even 4-bit systems (with only 16 possible values). The more modern ASCII system uses the 8-bit byte for each character. Today, the Unicode-based UTF-8 encoding uses a varying number of byte-sized code units to define a code point which combine to encode a character.

The ancient Egyptian Hill-country or "Foreign land" hieroglyph (𓈉) is a member of the sky, earth, and water hieroglyphs. A form of the hieroglyph in color, has a green line-(banding) at the base of the hieroglyph. The hieroglyph refers to the hills, and mountains, on both sides of the Nile River, and thus the green references the verdant black farming land adjacent to the river proper. It is coded N25 in Gardiner's sign list, and U+13209 in Unicode. It is a determinative hieroglyph, simply conveying a meaning, and has no phonetic value.

Various colors, and patterning, may adorn the rest of the hieroglyph when the bottom is green.

In typography, a dingbat (sometimes more formally known as a printer's ornament or printer's character) is an ornament, specifically, a glyph used in typesetting, often employed to create box frames (similar to box-drawing characters), or as a dinkus (section divider). Some of the dingbat symbols have been used as signature marks or used in bookbinding to order sections.

In the computer industry, a dingbat font or pi font is a computer font that has symbols and shapes located at the code points normally designated for alphabetical or numeric characters. This practice was necessitated by the limited number of code points available in 20th century operating systems. Modern computer fonts containing dingbats are based on Unicode encoding, which has unique code points for dingbats.

The equals sign (British English) or equal sign (American English), also known as the equality sign, is the mathematical symbol =, which is used to indicate equality. In an equation it is placed between two expressions that have the same value, or for which one studies the conditions under which they have the same value.

In Unicode and ASCII it has the code point U+003D. It was invented in 1557 by the Welsh mathematician Robert Recorde.

Blackboard bold is a style of writing bold symbols on a blackboard by doubling certain strokes, commonly used in mathematical lectures, and the derived style of typeface used in printed mathematical texts. The style is most commonly used to represent the number sets ${\displaystyle \mathbb {N} }$ (natural numbers), ${\displaystyle \mathbb {Z} }$ (integers), ${\displaystyle \mathbb {Q} }$ (rational numbers), ${\displaystyle \mathbb {R} }$ (real numbers), and ${\displaystyle \mathbb {C} }$ (complex numbers).

To imitate a bold typeface on a typewriter, a character can be typed over itself (called double-striking); symbols thus produced are called double-struck, and this name is sometimes adopted for blackboard bold symbols, for instance in Unicode grapheme names.

Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. The World Wide Web Consortium's XML 1.0 Specification of 1998 and several other related specifications—all of them free open standards—define XML.

The design goals of XML emphasize simplicity, generality, and usability across the Internet. It is a textual data format with strong support via Unicode for different human languages. Although the design of XML focuses on documents, the language is widely used for the representation of arbitrary data structures, such as those used in web services.

Character encoding is a convention of using a numeric value to represent each character of a writing script. Not only can a character set include natural language symbols, but it can also include codes that have meanings or functions outside of language, such as control characters and whitespace. Character encodings have also been defined for some constructed languages. When encoded, character data can be stored, transmitted, and transformed by a computer. The numerical values that make up a character encoding are known as code points and collectively comprise a code space or a code page.

Early character encodings that originated with optical or electrical telegraphy and in early computers could only represent a subset of the characters used in languages, sometimes restricted to upper case letters, numerals and limited punctuation. Over time, encodings capable of representing more characters were created, such as ASCII, ISO/IEC 8859, and Unicode encodings such as UTF-8 and UTF-16.