i

Pronunciation of IPA [iː]

* (mathematics, imaginary number): abbreviation of imaginary
* (engineering, electric current): abbreviation of French intensité du courant first used by M. André-Marie Ampère
* (computer programming, generic index): abbreviation of index
* (linguistics): abbreviation of identity

a+bi with a is real part and b is imaginary part

(mathematics, often in italics or bold) The imaginary unit; a fixed square root of -1. Graphically, i is shown on the vertical (y-axis) plane.

(mathematics, programming) A common variable name representing a generic index, especially in loops.

(financial mathematics) annual effective interest rate


tan

trigonometric function
trigonometric function

(trigonometry) The trigonometric function tangent.


sin

trigonometric function
trigonometric function#English

(mathematics) The trigonometric function sine.


r

Pronunciation of IPA [rɑː, ɑrrɑː] with the sound [r]


d

Pronunciation of IPA [dɑː, ɑdːɑː] with the sound [d]

(mathematics) the (path-independent, exact) differential of a quantity

(financial mathematics) annual effective discount rate


n

From the old Latin N, from the Greek Ν (nu), from an archaic reversed Greek N, from the Phoenician symbol 𐤍; possibly from an earlier Egyptian hieroglyph of a resting Egyptian cobra, D (𓆓).

(mathematics) An arbitrary natural number.


c

(mathematics) The space of convergent sequences.


z

Pronunciation of IPA [zɑː, ɑzzɑː] with the sound [z]

f(x,y,z)= sin x+ cos y+ tan z

(mathematics) Used to denote a real variable when x and y are already in use.

coordinate system
coordinate system#English

(mathematics) Used to denote the third coordinate in three-dimensional Cartesian and cylindrical coordinate systems.

‖z‖=z·̄z

(mathematics) Used to denote a complex variable.

(statistics) Used to denote a value of a standard normal random variable.


e

Close-mid front unrounded vowel
e
e (mathematical constant

Pronunciation of IPA [eː]

Modification of capital letter E in uncial script, from Ancient Greek Ε (E, Epsilon).

(mathematics) The base of natural logarithms, also known as Euler's number, a transcendental number with a value of approximately 2.718281828459…

1.2566e-6 = 1.2566 × 10⁻⁶

(sciences, computing) Symbol separating mantissa from the exponent in scientific notation.

a ∘ e = e ∘ a = a

(algebra, group theory) identity element.

In addition, we included here another effect—the modulation of the radiation pressure force by the orbital eccentricity of Mars, e#x5F;M#x3D;0.093—an effect, whose existence was first pointed out by Juhász and Horányi (1995) […]

2006 August, Alexander V. Krivov, Artem G. Feofilov, Valeri V. Dikarev, “Search for the putative dust belts of Mars: The late 2007 opportunity”, in Planetary and Space Science, volume 54, numbers 9–10 (in English), →DOI, page 873:


ln

(mathematics): Probably from New Latin logarithmus naturalis (“natural logarithm”). At the time of the discovery of logarithms and e, Latin was the language of science.

der

ln x= log ₑx
ln e=1

(mathematics) natural logarithm; logarithm to the base e.


XXX

From the reduplication of X (“a placeholder for any letter or word”).
The currency code was adopted in October 1976 and officially introduced in 1978 with ISO 4217 by the International Organization for Standardization (ISO).

rdp

(computing) Used as a placeholder in source code to mark that some work still has to be done.


Pr

Pr(B|A)=(Pr(A|B)·Pr(B))/(Pr(A))


li

logarithmic integral
logarithmic integral

(mathematics) The symbol for the logarithmic integral function.


Derives from overset Io, an abbreviation of either interiectiō (“interjection”) or the interjection iō (“hey!”), placed at the end of an exclamation to mark it as such. It expresses admiratio (“awe, wonderment”) in the clause.

5! = 5 × 4 × 3 × 2 × 1 = 120

five factorial equals 120

(mathematics) The factorial: the result of a multiplication of all integers from 1 to the given number.

programming language
programming language

(computing, in many programming languages) A Boolean negation, the not operator, serving to invert the truth value of what follows.

(computing, e-mail) Formerly used as a separator between hostnames in an e-mail address for the purpose of routing a message (called bang path notation).

(computing, IRC) Used as a separator between a user's nickname and ident.


Tenth century “West Arabic” variation of the Nepali form of Hindu-Arabic numeral ٠ (compare Devanāgarī script ० (0)), adopted for use with the Latin script in Europe. See 0 § History for more.

0̸

slashed zero, available only as a combination of Unicode characters, variation selector or through font features

x5C;exists#x5C;,#x5C;mathbf#x7B;0#x7D;#x3A;#x5C;foralla#x5C;inA#x3A;#x5C;mathbf#x7B;0#x7D;#x2B;a#x3D;a#x2B;#x5C;mathbf#x7B;0#x7D;#x3D;a

(mathematics) The identity element with respect to addition.

f : Bᵏ → B : B = {0, 1}

A&B&C=0 → A=0 || B=0 || C=0

(mathematics, computer science) A Boolean or truth value corresponding to false.

(computing) Indicates that the number that follows is in octal.

select currency expressions containing ‘0’


A West Arabic numeral, ultimately from Indic numerals (compare Devanagari २ (2)), from a cursive form of two lines to represent the number two. See 2 § Evolution for more.

(mathematics) The two-element Boolean algebra, two-point discrete space or a (canonical) two-element set.


Tenth century “West Arabic” variation of the Nepali form of Hindu-Arabic numerals (compare Devanagari script १ (1, “éka”)), possibly influenced by Roman numeral Ⅰ, both ultimately from using a single stroke to represent the number one. See 1 § As a digit on WikipediaWikipedia for more.

a×1 = a

(mathematics) The identity element with respect to multiplication in a ring.

(computer science) Bit state corresponding to binary digit 1, or on or true.

f : Bᵏ → B : B = {0, 1}

(mathematics) A Boolean or truth value corresponding to true.

topological space
topological space#English

(mathematics) The one-point topological space, trivial ring, trivial group, a category with a single object or a (canonical) singleton.

indicator function
indicator function#English

(mathematics, set theory) indicator function of a set.


A stylized form of Latin et (“and”). Romans used such symbols (ligatures) from at least the first century C.E., but the character may not have acquired its present form until the advent of calligraphy in the Middle Ages. Compare ⁊ and +, of same meaning and similar derivation.

Ꜳꜳ Ææ ᴁᴭ Ǽǽ Ǣǣ Ꜵꜵ Åå Ꜷꜷ Ꜹꜹ Ꜻꜻ Ꜽꜽ ct ȸ Ǳǲǳ Ǆǅǆ ᴂᵆ ᴔ & ﬀ ﬁ ﬃ ﬂ ﬄ ℔ Ĳĳ Ǉǈǉ Ỻỻ Ŋŋ Ǌǋǌ Œœ ɶ Ꝏꝏ Ȣȣᴕ ȹ ẞß ﬅﬆ ᵫ Ůů Ww Ꝡꝡ

(programming) Used in some programming languages for different purposes.

(networking) In a URL, separates each field-value pair of a query string .


log

if x=bʸ then log _b(x)=y


א

Modification of Aramaic 𐡀 (ā, ē, “Ālef”), closely related to Syriac ܐ (“Ālap, Olaf”) and Arabic ا (ā ʾ, “alif”), ultimately from Phoenician 𐤀 (“alef”).

(mathematics) ℵ (a transfinite cardinal number)


sinh

(trigonometry) The hyperbolic function hyperbolic sine.


π

(mathematics) Pi, an irrational constant representing the ratio of the circumference of a circle to its diameter; approximately 3.14159265.


Σ

(mathematics) Σ. Sum over a set of like terms:

(topology) suspension or reduced suspension

existential quantifier
existential quantifier

(mathematics) A class (in the arithmetical hierarchy) of formulae whose outermost unbounded quantifiers are existential quantifiers


Introduced by Gerhard Gentzen who based it on the Latin letter A, by analogy with ∃.

universal quantifier
universal quantifier

(mathematics, logic) The symbol used in predicate calculus, etc, to represent the universal quantifier, meaning “for all”.


Introduced by Giuseppe Peano in Formulaire de mathematiqués (1897), from the uppercase Latin letter E. The modern variable-binding syntax first appeared in Principia Mathematica (1910).

(mathematics, logic) The existential quantifier, meaning "there exists (at least one)".


Derives from the punctus versus.
The Italian printer Aldus Manutius established the practice of using the semicolon mark to separate words of opposed meaning, and to indicate interdependent statements. The earliest, general use of the semicolon in English was in 1591.

<?php echo '
Hello World
'; ?>

(programming) Marks the end of a statement in some programming languages.


η

quantum field theory
quantum field theory

(mathematics) The metric tensor in quantum field theory.


NP

(computer science) The class of problems whose solutions can be checked in polynomial time.


sec

(trigonometry) Symbol of the trigonometric function secant.


Im

Im(a + bi) = b

(mathematics) Symbol for the imaginary part of a complex number.


Coordinate term: ∵


$ appears to have evolved circa 1775 in the United States from a common abbreviation for pesos, also known as piastres or pieces of eight, a P/raised-S ligature P^S. It was used in the US before the adoption of the dollar in 1785.
The "computing" sense is the result of homophony between English cache and cash, dollars being a form of cash.

How to provide additional D$ bandwidth?

2010, CIS501 lecture notes (in English), University of Pennsylvania:


(programming) Prefix indicating a variable in some languages, such as Perl, PHP, or shell scripts.


Use as a multiplication sign is usually attributed to English mathematician William Oughtred.

{1,2} × {3,4} = {(1,3),(1,4),(2,3),(2,4)}

(set theory, category theory) Cartesian product, categorical product.

(1,2,5) × (3,4,−1) = (−22, 16, −2)

(linear algebra) Vector product, cross product.


id

identity function
identity function#English


(computing) Used as a multiplication symbol; ×.

(algebra) Complex or transpose conjugate; conjugate.

In the language defined by AB*A, each string starts with an A, ends with a distinct A, and between them has zero or more Bs.

(algebra, computer science) Free monoid or Kleene star.

(linear algebra, functional analysis) Dual space.


trans*

(chiefly computing) Uses especially in computing.

Used as a wildcard to denote zero or more characters.

(Internet) Used to indicate a field of a form that must be filled out.

I'm our of time. / *out

(Internet slang) Used before or after a word to show a correction has been made, chiefly by the same participant.


res

mathematical analysis
mathematical analysis


A cursive variation of ᾱ or ᾱᾱ, the abbreviation of Greek ἀνά (aná) used in recipes and prescriptions with the meaning "of each", and later extended to accounting. (Other explanations have that it is ā, an abbreviation of Latin ad (“to”), or French à (“to”).)

My e-mail address is psychonaut@example.com.

(computing) The symbol used as a separator between a username and a domain name in an e-mail address ("at" the domain name).

(computing, IRC) The most common choice of configurable prefix symbol to identify a channel operator.


cosh

(trigonometry) The hyperbolic function hyperbolic cosine.


mod

7 mod 2 = 1


cis

Abbreviation, presumably from either English cosine and sine and the number i or translingual cos, i, and sin.

(mathematics) The function cis(x)= cos x+i sin x.


(logic) intensional disjunction, as in some relevant logics.

(mathematics) An operator indicating special-defined operation that is similar to addition.


The lunar crescent is an ancient symbol for the moon.
Its orientation varies between increscent and decrescent.

rarely 🌙. In the medieval Marcianus graecus 299 manuscript

graphical user interface
graphical user interface

(graphical user interface, signage) Do not disturb; quiet.

(graphical user interface, computing) Sleep mode; off.

(graphical user interface) Night mode: a colour scheme with light text on a dark background.


SAT

Abbreviation of Boolean satisfiability problem.

abbrev

(computing theory) The decision problem of deciding whether a given Boolean formula has an assignment of Boolean values to its variables that makes it true. A famous NP-complete problem.


Introduced by Arend Heyting in “Die formalen Regeln der intuitionistischen Logik” (1930)

(x ≠ y) ↔ ¬(x = y)


½

Lonely GM seeking yng penpals to pass ½ century sentence.

1979 April 14, Larry Beerli, “Personal advertisement”, in Gay Community News, page 15:


¾

4 pages on loose leaf notebook pages, 6 x 9 ¾.

2010, Peter Haring Judd, Elizabeth Wade White Papers Catalog and Finding Aid, Volume 1 (in English), New York Public Library, →ISBN, page 439:


(computing) A common prefix for escape characters.

Coordinate term: /

(computing) A pathname component separator in some operating systems, predominantly Microsoft ones.


exclusive disjunction
exclusive disjunction

(programming) Bitwise exclusive disjunction.

Press ^F to find text in your document.

(computing, as part of a keyboard shortcut) Control key.

^W = end of control block

control character
control character#English

(computing) Indicates an ASCII control character in caret notation.


(a,b]=x∈ R ,|,a<x<b

(mathematics) Denotes an open endpoint of an interval.


[a,b)=x∈ R ,|,a<x<b


From ᵒ/c, from Nᵒ/c, an abbreviation of Italian numero per cento (“number per hundred”). For the extension to Astraea is derived from the shift-5 key on the keyboard for asteroid (5).

der

(computing) Used as a wildcard, usually in SQL, to stand for zero or more characters.

(computing, programming) Used as the symbol for the modulus, placed between two numbers, to get the remainder of the division of those numbers.


(mathematics) "is equivalent to"; "twiddles"

~p

(computing) user's home directory in Unix-like operating systems


(mathematics) An ASCII substitute for ′ (prime symbol).


lb

(computer science): From New Latin logarithmus binarii (“binary logarithm”).

lb(x)= log ₂(x). lb(2)=1

(computer science) Binary logarithm; logarithm to the base 2.


α

alpha

for names of this symbol in other language


ℵ

Introduced by Georg Cantor, based on the Hebrew letter א, initial letter of אינסוף (infinity).

(set theory) Symbol for the transfinite enumeration of the infinite cardinal numbers in order of magnitude, a function mapping ordinal numbers to infinite cardinals.


Bd

(computing) Symbol for baud, a unit of data transfer rate.


Con

ZFC ⊨ Con(PA)

(mathematics, logic) consistency predicate


Re

Re(a + bi) = a

(mathematics) The real part of a complex number.


Π

∏ₙ₌₁⁴n²=1²·2²·3²·4²=576

Capital pi notation
w:Multiplication#Capital pi notation

(mathematics) Product over a set of like terms:

arithmetical hierarchy
arithmetical hierarchy

polynomial hierarchy
polynomial hierarchy

(mathematics, logic, computer science) A class (in some hierarchy of formulae, like the arithmetical hierarchy or polynomial hierarchy) of those formulae whose outermost quantifiers are universal quantifiers.


F

From the Etruscan letter 𐌅 (v, “ve”), from the Ancient Greek letter Ϝ (W, “digamma”), derived from the Phoenician letter 𐤅 (w, “waw”), from the Egyptian hieroglyph 𓏲.


(mathematics, physics) The second time-differential. E.g. x (position), ẋ (velocity), ẍ (acceleration).


peru

Clipping of Peruvian brown. Added to X11's rgb.txt file on October 26 1989.

peru:

(computer science) The X11 color name of RGB hexadecimal value #CD853F.


L

From the Etruscan letter 𐌋 (l, “el”), from the Ancient Greek letter Λ (L, “lambda”), derived from the Phoenician letter 𐤋 (l, “lamed”), from the Egyptian hieroglyph 𓌅.

(computer science) Deterministic logarithmic space


tg

In the sense of ISO 639-1 code, from Italian tagico.

trigonometric function
trigonometric function

(mathematics) The symbol of the trigonometric function tangent.


D

* (chemistry, deuterium): abbreviation of deuterium
* (computing, hexadecimal 13): From its position as the thirteenth element of the series {1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F}
* (Germany): abbreviation of German word Deutschland (“Germany”)

(computing) Hexadecimal symbol for thirteen.

(mathematics) The differential operator in calculus and analysis.


E

From the Etruscan letter 𐌄 (e, “e”), from the Ancient Greek letter Ε (E, “epsilon”), derived from the Phoenician letter 𐤄 (h, “he”), from the Egyptian hieroglyph 𓀠.

2E5 = 2 × 10⁵

(sciences, computing) Symbol separating mantissa from the exponent in scientific notation.


C

* (element symbol, carbon): abbreviation
* (metrology, coulomb): abbreviation
* (computing, hexadecimal 12): From its position as the twelfth element of the series {1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F}

(computing, hexadecimal) The digit for 12.

C¹ functions are differentiable once, and C² functions are twice differentiable

∫ cos x,dx= sin x+C

constant of integration
constant of integration

(mathematics) The constant of integration.


P

From the Etruscan letter 𐌐 (p, “pe”), from the Ancient Greek letter Π (P, “pi”), derived from the Phoenician letter 𐤐 (p, “pe”), from the Egyptian hieroglyph 𓂋.

P(A) is the probability of A occurring

(computer science) class of problems solvable in polynomial time


V

From the Etruscan letter 𐌖 (u, “u”), from the Ancient Greek letter Υ (U, “ypsilon”), derived from the Phoenician letter 𐤅 (w, “waw”), from the Egyptian hieroglyph 𓏲. Doublet of Y and U.


T

From the Etruscan letter 𐌕 (t, “te”), from the Ancient Greek letter Τ (T, “tau”), derived from the Phoenician letter 𐤕 (t, “taw”), from the Egyptian hieroglyph 𓏴.


H

From the Etruscan letter 𐌇 (h, he), from the Ancient Greek letter Η (Ē, eta), derived from the Phoenician letter 𐤇 (ḥ, het), from the Egyptian hieroglyph 𓈈 or maybe 𓉗.

(mathematics) Homology group or cohomology group


Y

A late borrowing from the Ancient Greek letter Υ (U, “ypsilon”), first used to write Greek loanwords in Latin, derived from the Phoenician letter 𐤅 (w, “waw”), from the Egyptian hieroglyph 𓏲. Doublet of U and V.

(mathematics, computer science) A Fixed-point combinator; especially Haskell Curry's combinator defined as λ f.(λ x.f (x x)) (λx.f (x x))


Z

From the Etruscan letter 𐌆 (z, “ze”), from the Ancient Greek letter Ζ (Z, “zeta”), derived from the Phoenician letter 𐤆 (z, “zayin”), from the Egyptian hieroglyph 𓏭.

(physics, computer graphics) the depth dimension in a 3D environment


U

From the Etruscan letter 𐌖 (u, “u”), from the Ancient Greek letter Υ (U, “ypsilon”), derived from the Phoenician letter 𐤅 (w, “waw”), from the Egyptian hieroglyph 𓏲. Doublet of Y and V.

uniform distribution
uniform distribution

(mathematics, statistics) uniform distribution


M

(mathematical analysis) A generic manifold.


S

From the Etruscan letter 𐌔 (s, “es”), from the Ancient Greek letter Σ (S, “sigma”), derived from the Phoenician letter 𐤔 (š, “šin”), from the Egyptian hieroglyph 𓌒.

(mathematics, computer science) The S ("substitution") combinator, defined as Sxyz = xz(yz), used in SKI calculus


Q

English: max Q

Ancient Greek language
Egyptian language
Etruscan language
Phoenician language
Q

From the Etruscan letter 𐌒 (q, “cu”), from the Ancient Greek letter Ϙ (Q, “qoppa”), derived from the Phoenician letter 𐤒 (q, “qop”), from the Egyptian hieroglyph 𓃻.

(logic, mathematics) Robinson arithmetic.


O

From the Etruscan letter 𐌏 (o, “o”), from the Ancient Greek letter Ο (O, “omikron”), derived from the Phoenician letter 𐤏 (ʿ, “ʿayin”), from the Egyptian hieroglyph 𓁹.

(mathematics) big O: a class of functions asymptotically bounded from above by a specific function, up to a constant factor

(linear algebra, group theory) orthogonal group


diag

(linear algebra) a function that takes an n-element vector a and outputs an n by n diagonal matrix A where A_ii=a_i


I

From the Etruscan letter 𐌉 (i), from the Ancient Greek letter Ι (I, iota), derived from the Phoenician letter 𐤉 (y, yod), from the Egyptian hieroglyph 𓂝.

(mathematics, linear algebra) identity matrix

(mathematical analysis, topology) the (closed) unit interval; [0, 1]


ANG

(computing) Animated Network Graphics; an alternate name for APNG (Animated Portable Network Graphics)


exp

exp(x) = eˣ

exponential function
exponential function


SU

special unitary group
special unitary group


tr

(mathematics) The symbol for the trace function on square matrices.


ax²+bx+c=0 rArr x=(-b plusmn √)/(2a).

(mathematics) Either value as a result of addition or subtraction.


There are two primary theories of the origin of the question mark. One is that ⟨?⟩ descends from the punctus interrogativus ⟨⹔⟩, which instructed the reader (or singer) to raise the pitch of their voice while coming to a stop.
Another theory is that it derives from overset Qo, an abbreviation of Latin quaestio (“question”), placed at the end of a question to mark it as such, and analogous to the derivation of ⟨!⟩.
There are no documented intermediary forms to support one theory over the other.

(programming) A wildcard for one character in query language.

(programming) The ternary operator in some programming languages.

(networking) In a URL, begins a query string (a series of data formatted as field-value pairs).


Coordinate term: ∴


arcsec

(mathematics) The symbol of the inverse secant, or arcsecant, function.


(mathematics) ∑. Sum over a set of like terms:


Gottfried Leibniz based the symbol on the Latin word summa (“sum”), which he wrote ſumma (with a long s ⟨ſ⟩). This use first appeared publicly in his paper De Geometria, published in Acta Eruditorum of June, 1686, but he had been using it in private manuscripts since at least 1675.

(mathematics) Denotes the integral over a given integrand, which follows this symbol.


From the Ancient Greek letter ϵ (lunate epsilon). The coinage is commonly attributed to Giuseppe Peano, who used the letter epsilon for set membership in his two papers from 1889.

x ∈ ℕ denotes that x is within the set of natural numbers.

(mathematics) Is an element in the set of…


approximately equal to; congruent to; isomorphic to

If two quantities A and B are approximately equal, this is written A ≈ B.

Eric Weisstein, Wolfram Mathworld, "Approximately Equal"


The functions f and g satisfy f≡g if and only if their respective domain of definition coincide, and if f(x)=g(x) for all x in this domain.

(mathematics) "Is identically equal to".

(mathematics) "Is defined as, is set to".

15≡3 mod 4, since both 15 and 3 gives a remainder of 3 when divided by 4.

(number theory) "Is congruent to"; used in calculations of modulo.

elementary equivalence
elementary equivalence

(computing, dated) ISO 2047 symbol for Line Feed.


f′(x)= df(x)/dx

A′ = Aᵀ

t, t′, t″, t‴, t⁗, …

A, A′, A″, A‴, A⁗, …

(geometry) Used to distinguish two or more points, lines, etc. with the same name


In the modern sense as the equal sign, first attested in The Whetstone of Witte (1557) by Welsh mathematician Robert Recorde, in which the two parallel lines expressed equality, because, as Recorde wrote, "bicauſe noe .2. thynges, can be moare equalle" ("because no two things can be more equal").

abbr

The whetstone of witte, whiche is the seconde parte of Arithmetike: containyng thextraction of Rootes: The Coßike practise, with the rule of Equation: and the woorkes of Surde Nombers

(mathematics) The equal sign. It asserts that two quantities or expressions have the same value.

(depending on context)

The statement f(x)=O(log²x) means that as x gets arbitrarily large, f(x) will never grow faster than some constant multiple of log²x.

(mathematics, computing theory, abuse of notation, with big O notation) Is. Used to state the relation that the growth rate of the expression on the left side of the sign is bounded or limited by that of the expression on the right.

$price=18.95 (this causes $price to be 18.95 from now on)

(programming) The assignment operator. It assigns a value to a variable.

(programming) An operator that compares if two values are equal. In some languages, == is used instead.


β

IPA


Γ

(mathematics) the gamma function (usually written as Γ-function). An extension of the factorial to complex numbers


ζ

Riemann zeta function
Riemann zeta function

(mathematics) A mathematical function formally known as the Riemann zeta function.


γ

Euler-Mascheroni constant
Euler-Mascheroni constant

(mathematics) the Euler-Mascheroni constant


ι

(mathematics) sometimes used to write the imaginary unit


δ

(mathematics) A (path-dependent, inexact) differential.

For any ϵ>0, there is a δ>0 …

(mathematics) A small number, usually accompanied by ε.

(mathematics) Kronecker delta or Dirac delta.


Θ

(set theory) Θ, the ordinal number with the same cardinality as the smallest set larger than the real numbers; the smallest nonzero ordinal number such that there exists no surjection onto it from the real numbers.


ξ

Joined, cursive variant of Ξ; see joined variant of Ξ at right, showing development of ξ.


Λ

von Mangoldt function
von Mangoldt function

de Bruijn-Newman constant
de Bruijn-Newman constant

(mathematics) the de Bruijn-Newman constant


σ

(mathematics, statistics) Standard deviation.


τ

(mathematics, neologism) An irrational constant defined as the ratio of the circumference of a circle to its radius, equal to the radian measure of a full turn; approximately 6.283185307 (equal to 2π, or twice the value of π).


Φ

(mathematics) golden ratio conjugate ≈ 0.618...


ε

For each ε > 0, there exists a δ > 0, ...

(mathematics) An arbitrarily small number, usually in the company of δ.


Δ

(mathematics, sciences) Alternative form of ∆: change in a variable

symmetric difference
symmetric difference

(mathematics, set theory) Used to represent the symmetric difference (also known as the disjunctive union) of two sets


λ

mathematical analysis
mathematical analysis

(mathematical analysis) Lebesgue measure


φ

Named by mathematician Mark Barr after Ancient Greek Φειδίας (Pheidías) (Phidias), who supposedly used the golden ratio in his work.

(mathematics) The golden ratio, an irrational number with a value of approximately 1.618033988 which expresses the relationship that the sum of two quantities is to the larger quantity as the larger is to the smaller.


φ

Euler's totient function
Euler's totient function

(mathematics) Euler's totient function, an arithmetic function that counts totatives


χ

IPA

characteristic function
characteristic function#English

characteristic polynomial
characteristic polynomial#English

(mathematics) characteristic function (any meaning) or characteristic polynomial


ω

(mathematics, set theory) The first (countably) infinite ordinal number, its corresponding cardinal number ℵ₀ or the set of natural numbers (the latter of which are often defined to equal the former).


x

History of the International Phonetic Alphabet

Pronunciation of IPA [xa axa] with the sound [x]

The variable name comes from usage in Spain, as up to the 16th century ⟨x⟩ had the sound value /ʃ/ in Spanish, so was used to transcribe Arabic ش (š) used for the purpose of a variable as an abbreviation of شَيْء (šayʔ, “thing”). Its sound value in Spanish has since then become /x/, which explains the decision made in the circle of the International Phonetic Association to assign this character to the voiceless velar fricative. Compare English hickey (“an object whose name is not recalled; bruise-like mark made during petting by pressing the mouth to the skin”) for the development of the sense of a communicated kiss.

ncog

(mathematics) A name for an unknown variable.

Cartesian coordinates
Cartesian coordinates

(mathematics) The first coordinate in Cartesian coordinates, representing horizontal position.


x

Originates in given multiples of the speeds specified in the original CD and DVD standards, then, by reason of the actual unit being without name but just implied by the multiplication sign, reinterpreted as or used as if a unit, considering also that data transfer speed is variable, so that now, bolstered by stylization of the sign in the marketing of manufacturers, either spelling, with the multiplication sign or with the ex borrowed from the iconic mathematical variable sign, seems correct.

(computing) A unit of transfer rate of CD drives, equal to 150 KiB per second.

(computing) A unit of transfer rate of DVD drives, equal 1.32 MiB per second.


ang

(computing) Alternative letter-case form of ANG.


t, t′, t″, t‴, t⁗, …

A, A′, A″, A‴, A⁗, …

(geometry) used to distinguish two or more points, lines, etc. with the same name


(∃!x: P(x)) ↔ ∃x:(P(x) ∧ ∀y:(P(y) → (y = x)))

existential quantifier
existential quantifier

(mathematics) The symbol used in predicate calculus, etc, to represent the unique existential quantifier, meaning "there exists exactly one".


(mathematics) A symbol representing a product over a set of terms.


(mathematics, physics) A vector pointing into the page.

(computing, dated) ISO 2047 symbol for Shift Out

(logic) intensional conjunction, as in some relevant logics.


The set-theoretic meaning of this symbol was introduced by the Bourbaki group in their treatise Éléments de mathématique. André Weil has said in his autobiography that he based it on the Norwegian letter Ø.

(set theory) A set with no elements: the empty set.


tanh

(trigonometry) The hyperbolic function hyperbolic tangent.


(programming) Represents null coalescing operator or an operator with similar functions in some programming languages. Returns the second operand if the first returns null or is unset, with variations depending on the programming language.


arg

(mathematics) The symbol for the argument function, which finds the polar angle of a complex number.


sinc

cardinal sine function
cardinal sine function#English

(mathematics) A symbol of the cardinal sine function. (f(x) = sin(x)/x)


head

∧ or #x5C;land (English symbol name wedge)

land (canonical)
wedge (English name symbol)

(mathematics, logic) The conjunction operator, forming a Boolean-valued function, typically with two arguments, returning true only if all of its arguments are true.

(chiefly algebra and order theory) meet, infimum


coth

hyperbolic cotangent
hyperbolic cotangent

(mathematics) The hyperbolic function hyperbolic cotangent.


sech

(mathematics) The hyperbolic function hyperbolic secant.


ent

Abbreviation of French partie entière, Spanish parta entera, etc.

(mathematics, rare) A symbol for the floor function.


plim

For a sequence {Xₙ} of random variables underset n→∞operatorname plim,X_n=X is the same as lim _(n→∞) operatorname Pr big (|X_n-X|≥ε big )=0 (∀ε>0)


used when omitting a section in quoted text

Save as...

Find and replace...

(computing) Indicates that a computer command will request further information, typically by opening a dialog box.


1, 2, 3, ..., 1000

1 + 2 + 3 + ... + 100

(mathematics) In a sequence of numbers, omits numbers, when the pattern to be followed is clear.

The square root of 2 is 1.4142135623730950488…

(mathematics) Indicates that an indefinite sequence of digits of an irrational number follows.


partial differential
partial differential


* (material implication): Adopted in Principia Mathematica, by Alfred North Whitehead and Bertrand Russell, as an adaptation of Peano's Ɔ.

(mathematics) Contains as a proper subset.

(informal, mathematics) Contains as a subset

material implication
material implication

(mathematics) material implication; "implies", "if … then"


6 ÷ 2 = 3

Since decimal numbers are based on powers of ten it is extremely easy to multiply or divide by 10ⁿ, where n is a positive integer. To multiply a number by 10ⁿ, just move the decimal place n places to the right. For example, 24.345 × 10² = 2,434.5. […] To divide a number by 10ⁿ, just move the decimal place n places to the left. For example, 24.345 ÷ 10² = 0.23345.

2009, Blair Madore, GRE Math Workbook (in English), Barron's Educational Series, →ISBN, page 73:

(mathematics, especially Anglophone countries) division

÷50% (meaning a 50% reduction)

(mathematics, non-Anglophone countries) negative, minus


Use as a multiplication or product operator is usually attributed to German polymath Gottfried Wilhelm Leibniz.

7 · 8 = 56

(1,2,5) · (3,4,−1) = 6

(mathematics, vectors) The dot product operator.

If we have f(x,y) we can analyze the properties of f(·,y) which is a function of x found by fixing a particular y.

(mathematics) Indicates what elements can vary.


ℕ

The capital "N" is used this way in Formulario mathematico (1894) by Giuseppe Peano. The usage of blackboard bold dates to the 1960s.

(mathematics) The set of natural numbers, which may either include zero or not.


cos (x±y)= cos x cos y∓ sin x sin y⟺ big ( cos (x+y)= cos x cos y- sin x sin y∧ cos (x-y)= cos x cos y+ sin x sin y big )

(mathematics) The minus-plus sign: used after ± to indicate that when the first operation is 'plus', this one is 'minus', and vice versa.


In its original sense "disjunction", probably from the initial letter of Latin vel (“or”).


ℚ

From the initial of Italian quoziente (“quotient”), notation proposed in 1895 by mathematician Guiseppe Peano.

(mathematics) The set of rational numbers.


ℤ

From abbreviation of German Zahlen (“numbers”).

(algebra, topology, order theory) That set, with some usual structure.


+ (English symbol name plus sign or plus)

plus sign (English name symbol)
plus (English name symbol)

antonym(s) of “addition or positiveness”

From a ligature of Latin et (“and”). Compare & and ⁊ of same meaning.

3 + 2 = 5

(arithmetic, algebra) Addition, additive operation.

+5 is different from −5

(mathematics) Explicitly indicates that the next number is positive.

lim _(x→a⁺)f(x) is the same as lim _(x↓a),f(x)

(mathematics) A disjoint union, a coproduct.

inclusive disjunction
inclusive disjunction

(mathematics, logic) An inclusive disjunction.

"My name is " + name + ". I am " + age + " years old."

(programming) A string concatenation in some programming languages (that might be ambiguous with an additive operation).


Press Ctrl+C to copy!

(computing) When placed between key names, indicates that they should be pressed simultaneously.


antonym(s) of “all except relative complement”

There are many theories regarding the origin of the minus sign. According to one theory, it originates from a handwriting form of the letter m (for minus) that came to resemble a horizontal bar, Another theory traces it back to a hieratic sign.

8 − 3 = 5

Aldrichimica Acta Volume 30 No 4 (pdf) from Sigma-Aldrich
Decomposition of 4 in the presence of cis-piperylene at room temperature results in the stereocontrolled formation of trans-cycloheptadiene 27 in 90% ee (96% ee at -78 °C).

−(−5) = 5

(mathematics) negative sign. "negative", "minus", "the opposite of"

{1,2,4} − {1,3,4} = {2}

(mathematics) Relative complement. "minus", "without".

lim _(x→a⁻)f(x) is the same as lim _(x↑a),f(x)


csch

(mathematics) The hyperbolic function hyperbolic cosecant.


ld

Abbreviation of Latin logarithmus dualis.

log ₂(x)=ld(x). ld(2)=1

(computer science) binary logarithm; logarithm to the base 2


lg

(mathematics and computer science): Abbreviation of Latin logarithmus generalis.

lg (x)= log ₂(x). lg (2)=1

(computer science) binary logarithm; logarithm to the base 2.

lg (x)= log ₁₀(x). lg (10)=1


△ABC

A triangle with vertices named A, B, and C in order.

(computing, dated) ISO 2047 symbol for Space


(set theory) A symbol representing symmetric difference.

(computing, dated) ISO 2047 symbol for Escape


T₂

International Union of Pure and Applied Chemistry

(topology) The Hausdorff property; a category of topological spaces with this property.


ÿ

(mathematics) The second-order differential of y, using Newtonian calculus notation; the y-component of the acceleration.


(English name slash or stroke or solidus)

slash (English name)
stroke (English name)
solidus (English name)

The various uses of the present symbol derive from several sources. The medieval virgule (Latin virgula) was an oblique or vertical line that served as a comma, period, and caesura mark and is still used in literary contexts to mark line breaks in verse. (This mark separately developed as the comma ⟨,⟩ and caesura mark ⟨‖⟩ and some senses of the vertical bar ⟨|⟩.) The shilling mark (Latin solidus) was variously written s. or as the long s ſ. This eventually developed into a single unpunctuated slash; its use to separate shillings from pence was sometimes generalized to any currency division. Most mathematical senses derived from the earlier horizontal fraction bar (as in 12, usually attributed to Arabic mathematician al-Hassar), rewritten with a slash by the 18th century to permit fractions to be written on a single line. As a separator and conjunction, it represents an oblique form of the dash ⟨–⟩ or hyphen ⟨-⟩. Its use to mark supposed actions derives from command formatting in online chat forums, while its use to comment on preceding text derives from its use in some programming languages to form closing tags. Its present British name stroke derives from its use in telegraphy; its present American name slash gained wide currency from its use in computing.

QUIT? Y/N

(computing) Used to separate commands or keys that can be typed, usually in a command prompt.

I support him completely /sarcasm

(informal, programming, text messaging) Denotes a given attribute of the preceding content in the manner of a closing tag. See tone tag.

(computing) Used to separate the nested directory levels in a file or URL path.

operating system
operating system#English

(when used in isolation) The root path of a Unix or Unix-like operating system.


(mathematics) A single-line division sign, used with full-size numerals. See also ∕ (“division slash”).

(mathematics) A single-line fraction divider, used with full-size numerals. See also ⁄ (“fraction slash”).


(logic) A contradiction; a truth value corresponding to false.

(algebra) The bottom element of a lattice.

(computing, dated) The ISO 2047 symbol for Start of Text.


⅔

(mathematics) The symbol for two-thirds.


如圖2.1-7，△ABC及△DEF兩三角形全等，△ABC ≅ △DEF。

2017, 專門用來打好幾何基礎的數學課本 [A mathematics textbook designed to build a good foundation in geometry], volume 1 (in Chinese), Wu-Nan Book Inc., →ISBN, page 95:

As shown in Figure 2.1-7, △ABC and △DEF are two congruent triangles, △ABC ≅ △DEF.

Suppose that G ≅ H. Then there exists an isomorphism f, say, from G to H.

2011 May 5, Clive Reis, Abstract Algebra: An Introduction To Groups, Rings And Fields (in English), World Scientific Publishing Company, →ISBN, page 137:

(algebra, category theory, logic) Isomorphic to.


ℝ

In Stetigkeit und irrationale Zahlen (1872) Richard Dedekind uses R to denote rational numbers and ℜ to denote real numbers. The usage of blackboard bold dates to the 1960s.

(mathematics) This set, equipped with any of its standard structure; the real line.


ℂ

(mathematics) The set of complex numbers.

(mathematics) This set, equipped with any of its standard structure.


(programming) Decrement by 1 in certain programming languages such as C and Java.

if pizza == "plain cheese" -- Checks if pizza is "plain cheese".

SELECT id, name, birth_date -- Selects fields from a table.

programming language
programming language#English

(programming) Starts a single-line comment in some programming languages, including Ada, Haskell, and Lua, as well as some query languages.


^W

control character
control character#English

(computing) The ASCII control character end of transmission block in caret notation.


^H

(computing) The ASCII control character backspace in caret notation.


Arg

(mathematics) The principal value of the argument function.


s.l.

Abbreviation of sine loco (“without place”).

abbreviation of

(bibliography, proscribed) no place of publication given


ind

* (winding number): Ultimately from Latin index.

(geometry, topology, mathematical analysis) winding number


(mathematics) Any of the Weierstrass elliptic functions.


ctn

(mathematics, obsolete) The cotangent function.


atan

trigonometric function
trigonometric function

(trigonometry) The symbol of the trigonometric function arctangent.


(mathematics) The symbol used in predicate calculus meaning "there does not exist".


Alternative form: >>

Alternative form: >>

The n-Vector p ≫ q if pᵢ > qᵢ for all i in [1,n].

(mathematics) Greater than for every element (of a set).

(programming) Alternative form of >> (right shift operator).


Alternative form: <<

Alternative form: <<

The n-Vector p ≪ q if pᵢ < qᵢ for all i in [1,n].

(mathematics) Less than for every element (of a set).

(programming) Alternative form of << (left shift operator).


Introduced by the B programming language, which also used "!" for boolean negation, and inherited by its successor C. Later adopted more widely.

(programming) In some programming languages, an operator that compares two values for inequality, yielding a true result if they differ.


A ∋ b


A ∌ b

(mathematics) Does not contain as member.


(category theory) The unique object in a category with a single object.


Reversed (or backwards) version of the lowercase lunate epsilon ϵ. Introduced by Giuseppe Peano in 1889 in "Principles of arithmetic, presented by a new method" http://jeff560.tripod.com/set.html.


(mathematics) neither greater than nor equal to


(mathematics) neither less than nor equal to


From ∧ (“AND”) and the overline meaning "NOT".

(p ⊼ q)


From ∨ (“OR”) and the overline meaning "NOT".

(p ⊽ q)


From ∨ (“OR”) and the underline meaning "Exclusive".

(p ⊻ q)


(mathematics) triple integral (an integral over three variables).


(mathematics, category theory) n-ary coproduct


(mathematics) double integral (an integral over two variables).


(mathematics) the n-ary conjunction or meet operator

universal quantifier
universal quantifier


(logic, algebra) the n-ary disjunction or join operator


From the Ancient Greek capital letter Δ.

∆x the change in variable x

(mathematics) An increment or change in a variable.

symmetric difference
symmetric difference

(set theory) The symmetric difference symbol.

(mathematics, physics) The Laplace operator.


p = −iħ∇

∇f(x, y, z)

differential operator
differential operator

(mathematics) the gradient differential operator


ż

(mathematics) The differential of z, using Newtonian calculus notation; the z-component of the velocity.


ℑ

(mathematics) The imaginary part of an complex number


ℜ

(mathematics) The real part of a complex number.


300∕60 = 5

(mathematics) Used as a division sign, the same as ⟨÷⟩ (division/minus) or ⟨:⟩ (ratio/division), depending on the country.


ℶ

(2)+ðב₀=א₀, ב_(α+1)=2, and lim ב_λ→ sup ב_α:α<λ for a limit ordinal λ.

(set theory) Symbol for the cardinality of an infinite set in a iterative hierarchy of power sets, starting with ℵ₀. Usually indexed by an ordinal number.


1⁄2 of 10 is 5

(mathematics) Used to separate the numerator from the denominator in fractions.


ℍ

The first letter of the surname of William Rowan Hamilton (1805–1865), written in blackboard bold.

(mathematics) The symbol for the set of quaternions.


ℙ

(mathematics) A symbol used to denote the probability of an event.


ℓ

(mathematics) Sequence space on Wikipedia.Wikipedia


∛x=x


∜x=x


Introduced into mathematical usage by Paul Halmos, modeled after the end sign ■ (a printer’s ornament or dingbat used to indicate the end of an article or story) found in popular print media.


{ 4, 1, 5, 3 } ∖ { 3, 1, 9 } = { 4, 5 }


If a universe U is defined, then the complement of a set A is denoted by the following equivalent notations A^C, A′, ∁A, ∁_UA, or U ∖ A.


t, t′, t″, t‴, t⁗, …

A, A′, A″, A‴, A⁗, …

(geometry) used to distinguish five or more points, lines, etc. with the same name


t, t′, t″, t‴, t⁗, …

A, A′, A″, A‴, A⁗, …

(geometry) used to distinguish four or more points, lines, etc. with the same name


(sciences, mathematics) uncertainty range


head

✓ (English symbol name tick or checkmark or check)

tick (English name symbol)
checkmark (English name symbol)
check (English name symbol)

(computing, dated) ISO 2047 symbol for Acknowledge.


(mathematics) does not divide, is not a divisor of.


From a variant of the Latin virgula, which separately developed into ∕ (division slash).

Three divides six or Three is a divisor of six.

(mathematics) Divides evenly into; used to mark divisors.


⅛

(mathematics) an eighth: the number by which 8 must be multiplied to obtain 1


⅞

(mathematics) seven-eighths: the number by which 8 must be multiplied to obtain 7


⅜

(mathematics) three-eighths: the number by which 8 must be multiplied to obtain 3


⅝

(mathematics) five-eighths: the number by which 8 must be multiplied to obtain 5


AB∥CD indicates that line AB is parallel to line CD


for all x not less than three

x is not less than three


for all x not equivalent to three

x is not equivalent to three


(set theory) A generic strict order relation.

elementary substructure
elementary substructure

(logic) is an elementary substructure of


mathbf V_ω⊧ mathsf ZFCᶠⁱⁿ

T⊧φ if and only if T⊢φ

semantic consequence
semantic consequence

(mathematics, logic) semantic consequence


⊢ developed from ⊦, used to signify assertions in Principia Mathematica; in turn derived from idiosyncratic two-dimensional notation for logic employed in Begriffsschrift.

mathsf PA⊢∀a∀b:a+b=b+a


Alternative form: >>>

(programming) Alternative form of >>> (right shift operator).


α ⧟ β means α ⊸ β and β ⊸ α


(geometry) transversal intersection (the intersection of one-dimensional submanifolds of a two-dimensional manifold)


(computing, dated) ISO 2047 symbol for Horizontal Tabulation


(computing, dated) ISO 2047 symbol for Carriage Return


Alternative form: <<<

(programming) Alternative form of <<< (left shift operator).


(computing) cloud technology (computing, storage)


(computing) The object replacement character, sometimes used to represent an embedded object in a document when it is converted to plain text.


Mordecai: He's not even here. He's playing basketball. […] You snooze, you lose. I'm sure this will only take a second anyways.

2011, "Slam Dunk", season 3, episode 7 of Regular Show Rigby: You can't even [create a website] right now, anyway. Muscle Man has the computer for the whole day. […]

[Mordecai turns on the computer, and an hourglass appears on the screen while the computer is booting.]

graphical user interface
graphical user interface

(graphical user interface) Indicates that the current application is busy performing an operation.


function composition
function composition


(mathematics) As; in the same proportion as.


In mathematics, first introduced by Nicolas Bourbaki in their treatise Éléments de mathématique.

(mathematics, computer science) Used to mark an especially difficult passage or proof in a textbook.

Bourbaki dangerous bend symbol
Nicolas Bourbaki
Éléments de mathématique


(mathematics) Used varyingly for certain kinds of equivalence, e.g. congruence or isomorphism.


(mathematics) Not asymptotically equal to.


(mathematics) Less than or greater than.


(mathematics) a volume integral (a contour integral over three variables).


(mathematics) a surface integral over a closed surface (a contour integral over two variables).


n! ≃ √(n/e)ⁿ

π(N)≃N/(log (N)), where π(N) is the prime-counting function which is the number of primes less than or equal to N.

π ≃ 3.14159

tfrac 8 9 ≃ 0.889

tfrac 2 3 ≃ 0.667

tfrac 1 9 π² ≃ 1.097

tfrac 1 12 π² ≃ 0.822


★ (English symbol name star or five-pointed star)

star (English name symbol)
five-pointed star (English name symbol)

Likely from Egyptian 𓇼 (“determinative for stars and constellations”) (image: dwA). However, around the same time in Mesopotamia, non-cuneiform depictions of a star with eight- or six-points are attested; compare Sumerian 𒀭, a cuneiform character descended from such drawings.

der

(graphical user interface) Favourite (“to add to one's list of favourite items on a website or service that allows users to compile such lists”); favourites.

Indicates something or someone noteworthy, important, special or significant.

(graphical user interface) Bookmark (“to create a record of the address of a file or Internet page, serving as a shortcut to it”); bookmarks; save; saved items.


(mathematics) a contour integral; an integral over a closed loop.


(mathematics) a contour integral operating in the clockwise direction, as defined by the right-hand rule.


(mathematics) a contour integral operating in the anticlockwise direction, as defined by the right-hand rule.


(p ⊺ q)


(computing) symbol for the backspace key.


(mathematics) Neither a superset of nor equal to.


Hermitian conjugate matrix
Hermitian matrix

(mathematics) Hermitian conjugate matrix.


(computing) Command key on Apple Macintosh computer keyboards.


(mathematics) Neither a subset of nor equal to.


⅟

(mathematics) The numerator one with a slash, used in composing certain fractions.


⅗

(mathematics) The fraction three-fifths.


(computing) Used as a visual representation of the control character “start of heading”.


(computing) Used as a visual representation of the control character "enquiry".


(computing) Used as a visual representation of the control character "end of text".


(computing) Used as a visual representation of the bell character.


(computing) Used as a visual representation of the control character “horizontal tabulation”.


(computing) Used as a visual representation of the control character “backspace”.


(computing) Used as a visual representation of the control character “line feed”.


(computing) Used as a visual representation of the control character “acknowledge”.


(computing) Used as a visual representation of the control character "start of text".


(computing) Used as a visual representation of the control character “form feed”.


(computing) Used as a visual representation of the control character “end of transmission”.


(computing) Used as a visual representation of the control character "shift in".


(computing) Used as a visual representation of the control character “vertical tabulation”.


(computing) Used as a visual representation of the control character "shift out".


(computing) Used as a visual representation of the control character "carriage return".


(computing) Used as a visual representation of the control character "data link escape".


(computing) Used as a visual representation of the control character "device control four".


(computing) Used as a visual representation of the control character "end of transmission block".


(computing) Used as a visual representation of the control character "substitute".


(computing) Used as a visual representation of the control character "file separator".


(computing) Used as a visual representation of the control character "cancel".


(computing) Used as a visual representation of the control character "record separator".


(computing) Used as a visual representation of the control character "unit separator".


(computing) Used as a visual representation of the control character "negative acknowledge".


(computing) Used as a visual representation of the control character "end of medium".


(computing) Used as a visual representation of the control character "newline".


(computing) Used as a visual representation of the control character "delete".


(computing) Used as a visual representation of the control character "group separator".


(computing, dated) ISO 2047 symbol for Substitute Character


(computing, typography) An explicit space, as opposed to a tab character, or nothing at all.


(computing) Used as a visual representation of the control character "space".


(computing) Used as a visual representation of the control character "synchronous idle".


(computing) Used as a visual representation of the control character "device control one".


(computing) Used as a visual representation of the control character "escape".


(computing, dated) ISO 2047 symbol for Delete


(computing, dated) ISO 2047 symbol for Negative Acknowledge


(computing, dated) ISO 2047 symbol for End of Transmission


material implication
material implication#English

(logic, text-style only) material implication

(mathematics, text-style only) converges to

(mathematics, category theory, text-style only) morphism or a function, pointing from the domain to the codomain

Go to File → Save As → CSV file → OK.

(computing, text-style only) Indicates a series of steps to achieve a task in software.

(computing) The right-arrow key on a computer keyboard, used for navigation and various keyboard commands.


(computing) Used as a visual representation of the control character "device control three".


(computing) Used as a visual representation of the control character "device control two".


(computing, dated) ISO 2047 symbol for Synchronization


csc

(mathematics) The symbol of the cosecant function.


ẋ

(mathematics) The differential of x, using Newtonian calculus notation; the x-component of the velocity.


ẏ

(mathematics) The differential of y, using Newtonian calculus notation; the y-component of the velocity.


c₀

(mathematics) the space of sequences which converge to zero


⁺3 − ⁻5 = ⁺8

(mathematics, rare) Unary operator + to be distinguished from the binary operator +

(mathematics) Limit approached from the positive side

(mathematics, computer science) Kleene plus


(mathematics) An operator indicating special-defined operation that is similar to division.


(computing) The left-arrow key on a computer keyboard, used for navigation and various keyboard commands.

(mathematics, computer science) assignment


(computing) The enter key or the newline character.


MNG

(computing) Multiple-image Network Graphics (a raster image file format, designed to succeed multi-image static GIF (GIF 87b))


(computing, dated) ISO 2047 symbol for Bell


(computing) print screen (a command to capture the screen display as an image)


^J

(computing) The ASCII control character line feed in caret notation.


^G

(computing) The ASCII control character bell in caret notation.


(computing) The ASCII control character null in caret notation.


^I

(computing) The ASCII control character horizontal tab in caret notation.


^F

(computing) The ASCII control character acknowledgement in caret notation.


^B

(computing) The ASCII control character start of text in caret notation.


^O

(computing) The ASCII control character shift in in caret notation.


^X

(computing) The ASCII control character cancel in caret notation.


^A

(computing) The ASCII control character start of header in caret notation.


^M

(computing) The ASCII control character carriage return in caret notation.


^P

data link escape
data link escape#English

(computing) The ASCII control character data link escape in caret notation.


^E

(computing) The ASCII control character enquiry in caret notation.


^D

(computing) The ASCII control character end of transmission in caret notation.


^C

(computing) The ASCII control character end of text in caret notation.


^L

(computing) The ASCII control character form feed in caret notation.


^N

(computing) The ASCII control character shift out in caret notation.


^Q

(computing) The ASCII control character device control 1 in caret notation.


^K

(computing) The ASCII control character vertical tab in caret notation.


^S

(computing) The ASCII control character device control 3 in caret notation.


^Z

(computing) The ASCII control character substitute in caret notation.


^R

(computing) The ASCII control character device control 2 in caret notation.


^U

(computing) The ASCII control character negative acknowledgement in caret notation.


^V

(computing) The ASCII control character synchronous idle in caret notation.


^T

(computing) The ASCII control character device control 4 in caret notation.


^Y

(computing) The ASCII control character end of medium in caret notation.


`lsqb`

[a,b)=x∈ R ,|,a<x<b

[a,b[=x∈ R ,|,a<x<b

(mathematics) Denotes a closed left endpoint of an interval.

[a,b[=x∈ R ,|,a<x<b

]a,b[=x∈ R ,|,a<x<b

(mathematics) Denotes an open right endpoint of an interval.


`lowbar`

head

`lowbar` (English symbol name underscore or underline)

`lowbar` (canonical)
underscore (English name symbol)
underline (English name symbol)

Force is denoted with F. Centripetal force is denoted with F_c which may be written as F_c.

(mathematics, in plain text) Separates a symbol with a subscript character, representing a variant of the base symbol.

MS-DOS prompt: C:\>_

] [
Unsupported titles/Space#Translingual

visual display unit
visual display unit#English

(computing) Used to represent what would normally be a space ] [ in computing.

Used as a cursor to indicate a place where text can be typed. On visual display units, the underscore may be made to blink.

(programming) Especially as a prefix: used to denote a special identifier such as a global or private variable or a reserved symbol.

My email address is jon_smith@example.com.


`num`

`num` (English symbol name number sign or hash or pound sign or octothorpe)

`num` (canonical)
number sign (English name symbol)
hash (English name symbol)
pound sign (English name symbol)
octothorpe (English name symbol)

(mathematics, computer science) Concatenation.

(mathematics) Apartness, a binary relation such that if a#b, then any other element c is apart from at least one of a,b. See apartness relation.


`gt`

Go to File > Save As > CSV file > OK

(computing) Synonym of → (“indicates a series of steps to achieve a task in software”)

c:\users\home\> (Command Prompt in Microsoft Windows)

(computing) Indicates that the user is being prompted for input.


`vert`

`vert` (English symbol name vertical bar or vertical line or pipe)

`vert` (canonical)
vertical bar (English name symbol)
vertical line (English name symbol)
pipe (English name symbol)

(logic) The Sheffer stroke: joins two statements of which not both are true (nand).

X'=AX+F_1 in R_1=X∈R⁸|x_1<α_f

2006, K. Chung et al., Bifurcation analysis of a two-degree-of-freedom aeroelastic system with freeplay structural nonlinearity by a perturbation-incremental method, Journal of Sound and Vibration. According to the three linear branches of the bilinear function for a freeplay model, the phase space X∈R⁸ can be divided into three regions, R_i(i=1,2,3), where each corresponds to a linear system

(mathematics) Such that; having the property that.

f#x7C;#x5F;A#x3A;A#x5C;rightarrowB for any A#x5C;subseteq#x5C;operatorname#x7B;dom#x7D;(f).

(mathematics, of a function) Restricted to.

(mathematics, of an expression) Evaluated at.

the conditional probability of X given Y

Conditional probability
conditional probability

(programming) Used in some programming languages as the "bitwise or" operator.


A simplification of the punctus elevatus, ⟨⹎⟩.

Alternative form: ∶ (U+2236 RATIO)

6 : 2 = 3


John 3:14–16 (or John III:14–16)

(information science) Separate elements of a bibliographic reference, such as chapter and verses of the bible, or volumes and pages of a work.


C: is the default system drive on Windows.

(computing) Indicates a storage or media drive letter (with or without path).

(networking) Separates the parts of an IPv6 address.


`period`

The periodos of Aristophanes of Byzantium, ca. 200 BCE. Originally there were three dots: ⟨·⟩ at mid height (the comma), ⟨.⟩ at the baseline (the colon), and ⟨˙⟩ at capital height (the periodos). When minuscule writing became common, it proved difficult to make a three-way height distinction, and only the periodos was retained, though it shifted to the baseline.

point.x

the ‘x’ property of the ‘point’ variable

In various programming languages, the structure access operator.

echo 'I am currently ' . myAge(1981) . ' old.';

In various programming languages, the string concatenation operator.

ls .

list the contents of the current directory

In various operating systems, the current directory.

div.quotedtext {font-style: italic}

The class selector in CSS, which intends to format a class of an element. (A class can appear freely one or more times in a page, as opposed to the ID selector: #).

document.txt

the file with the base name ‘document’ and the extension ‘txt’

Separates a file name from its extension.

en.wiktionary.org

the Internet domain name with components ‘en’, ‘wiktionary’, and ‘org’

top-level domain
top-level domain#English

Separates the parts of the domain name of a website (including the subdomain and the top-level domain).

version 1.2.16

Separates the parts of a version number.

Separates the parts of an IP address (IPv4).

(regular expressions) Matches any single character.


(programming) A namespace or scope resolution operator in some programming languages.

2001:db8::ff00:42:8329 = 2001:0db8:0000:0000:0000:ff00:0042:8329

1 = 0000:0000:0000:0000:0000:0000:0000:0001

(networking) Contracted notation of an IPv6 address which contains consecutive zeros in between colons.


(computing, programming) Assignment. Indicates the that the value or computed expression on the right is to be stored in the variable or address location on the left.


`lt``gt`

(mathematics, programming) Not equal to.


sgn

sgn x

sgn(σ)

(mathematics, group theory) The sign or signature of a permutation.


th

(mathematics) Alternative form of tanh (“hyperbolic tangent”)


(logic) In linear logic, used to denote an intensional disjunction.


(logic) Denotes a definite descriptor in formal logic.


ℬ

(topology) A variable name for a Banach space.

(topology) A variable name for a basis of a topological space.


ℯ

(chiefly mathematics) e, the base of natural logarithms


ℰ

(mathematics, computer science) A level of the Grzegorczyk hierarchy


ℼ

(chiefly mathematics) A double-struck lowercase Greek letter pi


ℽ

(chiefly mathematics) A double-struck lowercase Greek letter gamma


ℾ

(chiefly mathematics) A double-struck uppercase Greek letter gamma


ℿ

(chiefly mathematics) A double-struck uppercase Greek letter pi


ⅆ

(chiefly mathematics) A double-struck lowercase letter d in an italic typeface


(mathematics, game theory) An arbitrary game.


ⅇ

(chiefly mathematics) A double-struck lowercase letter e in an italic typeface


ⅈ

(chiefly mathematics) A double-struck lowercase letter i in an italic typeface


ⅅ

(chiefly mathematics) A double-struck uppercase letter D in an italic typeface


SU(n)

Special unitary group
special unitary group


diam

diam(X):= sup d(x,y):x,y∈X


vec

vec(A)=[a_1,1,...,a_m,1,a_1,2,...,a_m,2,...,a_1,n,...,a_m,n]ᵀ

(mathematics) vectorization (of a matrix)


Fσ

From French fermé (“closed”) for the 'F' and French somme (“sum”) for the 'σ'. The 'σ' can be interpreted to mean "countable union."

mathematical analysis
mathematical analysis

(mathematical analysis, topology) A countable union of closed sets.


Gδ

From German Gebiet (“neighborhood”) for 'G' and German Durchschnitt (“intersection”) for the 'δ'.

(mathematical analysis, topology) A countable intersection of open sets.


ϖ

Bernoulli's lemniscate
lemniscate of Bernoulli

(mathematics) The lemniscate constant, a transcendental constant representing the ratio of the perimeter of Bernoulli's lemniscate to its diameter; approximately 2.62205755.

ϖ^κ

(mathematics) diameter of a model κ-plane:

ϖ

(mathematics) uniformizer of a localisation of a number ring at a regular prime ideal:


A Copy Items box is displayed. Expand the My Computer folder, if necessary, and then click on 💾 3½ Floppy (A:).

2004, Cia Training Ltd Staff, E-Quals Unit 021 It Principles Level 2 (in English), CIA Training Ltd., →ISBN, page 62:

(graphical user interface) A floppy disk.

7. Click 💾
Your change to the memo is saved.

2013, Jennifer Duffy, Carol Cram, Microsoft Word 2013: Illustrated Complete (in English), Cengage Learning, →ISBN, page 8:

(graphical user interface) An icon that represents saving digital data to any storage medium.


programming language
programming language

(programming) Increment by 1 (in certain programming languages such as C and Java).


JNG

(computing) JPEG Network Graphics (a raster image file format, using JPEG compression, with the file structure of PNG)


APNG

(computing) Animated Portable Network Graphics; a file format for animated multi-image raster graphics with lossless compression designed to replace Netscape GIF 89b format, based on the PNG file format


(mathematics) Approximately but not actually equal to.


(computing) The down-arrow key on a computer keyboard, used for navigation and various keyboard commands.


𝔠

(mathematics) cardinality of the continuum


◌̅ (English name overbar or overline or overscore or vinculum)

overbar (English name)
overline (English name)
overscore (English name)
vinculum (English name)

12 ÷ 7 = 1.7̅1̅4̅2̅8̅5̅ = 1.714285714285714285...

(mathematics) Drawn over repeating digits.

segment A̅B̅ has the same length as segment C̅D̅

(geometry) Drawn over letters which represent a line segment.

z̅ = x̅+̅i̅y̅ = x−iy

complex conjugate
complex conjugate#English

(mathematics) Indicates the complex conjugate of a complex number.

(statistics) Used to mark the mean of a sample.


praeclarum theorema

So named by G.W. Leibniz in his unpublished papers of 1690 (later published as Leibniz: Logical Papers in 1966), meaning "splendid theorem" in Latin.

The praeclarum theorema can be seen to correspond with the rule R⊗ of linear logic; given two sequents A⊢B and C⊢D one may infer (through the said rule) that A,C⊢B⊗D. Then one may further infer, through the rule L⊗, that A⊗C⊢B⊗D.

propositional calculus
propositional calculus

(logic) The following theorem of propositional calculus: (A → B) ∧ (C → D) → (A ∧ C → B ∧ D).


Originated in the notation for hexadecimal numbers in the C programming language (first major revision described in The C Programming Language, published 1978) and its descendants.

Available RAM using ARMulator or Evaluator-7T extends from 0x8000 to 0xffff while that using the LPC2102 with the Keil tools is from 0x40000000 to 0x40000fff.

2007, J. R. Gibson, ARM Assembly Language - an Introduction (in English), page 106:

(computing) Indicates that the number that follows is in hexadecimal.


irrational number
irrational number#English

(mathematics) Representing continuation of a predictable pattern, omitted medial members of a series, indefinite continuation of an irrational number, etc. The symbol is not formally defined and approximates to the use of the ellipsis in ordinary language.


5 - ⁻4 = 9

(mathematics, rare) negation, unary minus, to be distinguished from the binary subtraction operator

(mathematics) limit approached from the negative side


The use of this notation in modal logic was developed by C.I. Lewis.

∀𝑥□𝐹𝑥 → □∀𝑥𝐹𝑥 ⇔ ◊∃𝑥𝐹𝑥 → ∃𝑥◊𝐹𝑥

(logic, unfilled) possibility, possible, possibly

diamond principle
diamond principle#English


The bottom arrow pointing right is the rightward tab; the top arrow pointing left is the leftward tab, or "shift+tab" which may serve to reverse the role of tab in some programs.

⇆Tab to Move Down to Notes Button

(computing) The tab (tabulation) symbol found in keyboards.


graphical user interface
graphical user interface

(graphical user interface) A briefcase in Microsoft Windows, which is a folder able to synchronize files with another folder.


(databases) A primary key. (a column able to identify every row in the table)


(graphical user interface) an icon which converts speech into text


uniformly converges
uniform convergence#English

(mathematics, mathematical analysis) uniformly converges to


ẍ

(mathematics) The second-order differential of x, using Newtonian calculus notation; the x-component of the acceleration.


(mathematics, physics) the symbol indicating a vector product a.k.a. cross product


a ⟂ b ∧ b ⟂ c → a ∥ c


(computer science) blank symbol, used in Turing machine diagrams


⁻¹

multiplicative inverse
multiplicative inverse

(arithmetic, algebra) reciprocal; multiplicative inverse, inverse


(a) (rare) egressive airstream mechanism when used with a letter for an ingressive sound, e.g. [ʘ↑]

(b) exhalation when used alone, [↑].

(number theory, computer science) exponentiation

(computing) The up-arrow key on a computer keyboard, used for navigation and various keyboard commands.


(linguistics) cognate with ('A ⪤ B' means 'A and B are cognate')


□ABCD

A quadrilateral with vertices named A, B, C, and D in order.

(geometry) A quadrilateral, usually referred to a square or rectangle.

Coordinate term: ◇

[…] obtained by adding the standard modal operators □ (necessity) and ◇ (possibility) to paralogics.


(algebra, logic) Boolean value corresponding to truth


[f = (x ↦ x)] ↔ [∀x: f(x) = x]


(mathematics, category theory) epimorphism or surjection


PSL

special linear group
special linear group

(algebraic geometry) projective special linear group


The homomorphism from S → R that maps onto the identity map of R gives a retraction of the injective map R ↪ S.

(mathematics) embedding, injective map, monomorphism (written between the domain (source) and codomain (target) of the morphism)


ℵ₀

countably infinite
countably infinite#English

(mathematics, set theory) aleph-null, the cardinality of a countably infinite set


ω₁

(set theory) the first uncountable ordinal


(mathematics) Delimits a norm or a norm-like function, distinguished from a norm denoted by ‖·‖.


𝟙

indicator function
indicator function#English


Sⁿ

(topology) An n-dimensional sphere; the surface of an (n+1)-dimensional ball.


S²

(topology) sphere (the surface of a three-dimensional ball)


𝔼

ℰ was used in this meaning as early as 1901 in William Allen Whitworth's Choice and Chance with One Thousand Exercises. The symbol came either from English expectation (or expected value), German Erwartungswert or from French espérance (“hope”); "mathematical hope" was an early name for this concept, still used in French and recognised in some other languages.


(mathematics) Generic symbol for an addition-like operation, to distinguish it from addition denoted with +.

(computing) Unofficial symbol for the Windows Key because of its resemblance to the Windows logo, and is nearly identical to the Windows 11 logo.


(mathematics) Generic symbol for a subtraction-like operation, usually related to an additive operation ⊞, to distinguish it from subtraction denoted by −.

(computing, dated) ISO 2047 symbol for Data Link Escape


(computing, dated) ISO 2047 symbol for Enquiry


ℕ₊

(mathematics) The set of positive integers, i.e. natural numbers excluding zero.


ℕ₀

(mathematics) The set of natural numbers, including zero.


Exp

(mathematics, statistics) Exponential distribution


Pois

(mathematics, statistics) Poisson distribution


ess sup

(mathematical analysis) essential supremum


ess inf

(mathematical analysis) essential infimum


DTIME

(computer science) A class of problems solvable by a deterministic Turing machine in given asymptotic time.


(computer science) modified subtraction, cutoff subtraction: a binary operator which evaluates to the difference between its operands if it is non-negative, and to 0 otherwise


DSPACE

(computer science) A class of problems solvable by a deterministic Turing machine in a given asymptotic amount of space.


MSO

(logic, computer science) Monadic second-order logic.


material equivalence
material equivalence

(logic) material equivalence; if and only if

(computing) adjustable in horizontal direction


From SAT and 3, the number of literals per clause.

conjunctive normal form
conjunctive normal form

(computing theory) The decision problem of deciding whether a given Boolean formula in conjunctive normal form with three literals per clause is satisfiable. A famous NP-complete problem.


From SAT and 2, the number of literals per clause.

(computing theory) The decision problem of deciding whether a given Boolean formula in conjunctive normal form with two literals per clause is satisfiable.


TQBF

From English True (or totally) quantified Boolean formula.

∃x_1∀x_2∃x_3...Q_nx_nf(x_1,x_2,x_3,...,x_n)

Where Q_n is ∀ if n is even and ∃ if n is odd.

(computing theory) The decision problem of, given a Boolean function f on n variables, deciding whether the following formula is satisfiable:


Aut

(algebra, category theory) The set of automorphisms of a specific object.


Hom

Hom(U⊗V,W)≅Hom(U,Hom(V,W)).

(mathematics, chiefly category theory) The set of morphisms between two specific objects.


''1'' is text; 1 without quotation marks is a number.

(programming) Encloses a string literal in some programming languages.

Straight single quotation mark and apostrophe


Curved single quotation marks and apostrophes

"1" is text, 1 without quotation marks is a number.

(programming) Encloses a string literal in some programming and markup languages.

Search for "heads or tails" for the exact phrase. If you forget the quotation marks, you'll surely see results with "heads" and "tails" separately.

(computing) In some search engines, searches for the exact word of phrase.


`lcub` `rcub`

{ } (English symbol name curly brackets or braces)

curly bracket s (English name symbol)
braces (English name symbol)

10/2+3 = 5+3 = 8

10/{2+3} = 10/5 = 2

(mathematics) Encloses a mathematical phrase which has increased operator precedence.

{3.14} = 0.14

(mathematics) Indicates the fractional part.

Set of positive divisors of 6 = {1, 2, 3}.

The set of even numbers can be written as { n ∊ ℤ : ∃ k ∊ ℤ: n = 2k } .

Set of natural numbers between 2 and 3 = { }.

Alternative form: {}

doSomethingTwice () { return doSomething () + doSomething () }

programming language
programming language#English

(programming) Used in some programming languages, especially C-type languages.

if (x>4) { result = "congratulations!" }


⌊3.14⌋ = 3

⌊−4.28⌋ = −5

(mathematics) Indicates the use of floor function, rounds down a number to the nearest integer.


⌈1.414⌉ = 2

⌈−1.618⌉ = −1

(mathematics) Indicates the use of ceiling function, rounds up a number to the nearest integer.


20 / 2 + 8 = 10 + 8 = 18

20 / (2 + 8) = 20 / 10 = 2

(mathematics) Encloses a mathematical phrase that has increased precedence in terms of operators.

greatest common divisor
greatest common divisor#English

(mathematics) Denotes the greatest common divisor of two integers.

(x,y)

getSum (a, b)

result = a + b

return result

(programming) Used when defining a new function, enclosing the list of parameters.

result = getFirstNumber() + getSecondNumber() + getThirdNumber()

(programming) Used when calling an existing function, enclosing the list of arguments.

if (x > 7) then printf "success!" end

(programming) Used with some expressions and conditionals, like "if", "switch", "for", "while", etc., in certain programming languages.


`lsqb` `rsqb`

DROP TABLE tbl_name [, tbl_name] ...

(computing, programming) Encloses optional parameters in syntax help.


`lsqb` `rsqb`

4/(2x+ textbf [7+9])

(mathematics) Encloses a polynomial ring.

[·,·]:V⊗V→V

(mathematics) An alternating bilinear function satisfying the Jacobi identity; typically in the context of and as the operation of a Lie algebra, thus referred to as Lie bracket.

1 9-13\20 5-6

(mathematics) Encloses a matrix or vector.

1962, Jack Frohlichstein, Mathematical Fun, Games and Puzzles (in English), Courier Corporation, page 47

(mathematics) Singles out a digit or portion of an equation, for commentary.

(mathematics) Denotes the least common multiple of two integers.

least common multiple
least common multiple#English

t[1] = "one"

t[2] = "two"

(programming) In a number of programming languages, used as the array index operator, the subscript operator.


1 class Arrow a => ArrowChoice a, where
2 …
3 (⧻) :: a b c -> a b' c' -> a (Either b b') (Either c c')
4 …
5 infixr 2 ⧻

In the Haskell programming language, which allows arbitrary user-defined operators, the triple plus operator is a member of class ArrowChoice


var x = 5
x⧺; // x = 6

The double plus indicates the increment by one of the number. For instance


(computing, dated) ISO 2047 symbol for Start of Heading


(computing, dated) ISO 2047 symbol for End of Text


int x = random() // Defines x as a random number.

(programming) Begins a comment that is only applicable in the current line in some programming languages.

(networking) Indicates root path in a computer network (usually followed by a node name or an IP address).


For the purpose of error estimation and convergence studies, the deflection and energy norm, ||w|| and ||e||, are calculated …

2002, S. Long et al., A Meshless Local Petrov-Galerkin Method for Solving the Bending Problem of a Thin Plate, Tech Science Press

(mathematics) Used on either side of an object to denote the norm of that object.


Introduced by the B programming language, which used the symbol "=" for variable assignment. The reasoning given by the creators of the language is that assignment is more frequent than equality testing, and thus deserves the shorter operator. The syntax was inherited by its successor C, and later adopted more widely. See wikipedia:Relational operator#Confusion with assignment operators.

if x==1 then print "success!" end (prints "success!" if x equals 1)

(programming) In some programming languages, an operator that compares if two values are equal.


`vert` `vert`

The absolute value of minus three is three.

For x equals one, one and y equals four, five, the absolute value of the quantity x minus y is the square root of (open parentheses) the quantity one minus four squared plus the quantity one minus five squared (close parentheses) or five.

|A|

The set three, five, seven, and nine has a cardinality of four.

(mathematics) Marks the operation of finding the cardinality of a set.

connected component
connected component#English

(mathematics) Notes the number of connected components.


(computing) adjustable in vertical direction


`lt` `gt` `lt`/ `gt`

<p>This is a new paragraph.'''

[written by Mark Zuckerberg at the start of the movie, after he was dumped by his girlfriend Erica]

<p><i>9:48pm'. The truth is that she has a nice face. I need to do something to take my mind off her. Easy enough, except I need an idea.'

(computing) Used in HTML and XML to open and close an element.


(programming) Encloses a multi-line comment in some programming, markup and query languages.


`lt`!-- --`gt`

<!-- Note: I don't understand how this code works. -->

(computing) Encloses a multi-line comment in some markup languages, including HTML, XML, and SGML.


= non-breaking space

(computing) Encloses a character entity reference, which is displayed as a certain character in HTML and XML.


programming language
programming language

(programming) In some programming languages, a comparison operator that returns true if two values are equal and have the same data type.


The output of true && false is false.

(programming) The conditional "and" operator in some programming languages.


`lt` `gt`

{{#tag:syntaxhighlight|#include |inline="True"|lang="c"|style="white-space:pre-wrap;"}} – C example

{{#tag:syntaxhighlight|ArrayList|inline="True"|lang="Java"|style="white-space:pre-wrap;"}} – Java example

(programming) Encloses certain types of information in some programming languages.

{{#tag:syntaxhighlight||inline="True"|lang="html"|style="white-space:pre-wrap;"}} = displays an image

{{#tag:syntaxhighlight|
|inline="True"|lang="html"|style="white-space:pre-wrap;"}} = a line break

Unsupported titles/Less than trailing slash greater than#Translingual

(computing) Encloses certain tags in markup languages.

(computing) Encloses a standalone HTML tag. Compare < /> in XML.

Unsupported titles/HTML start tag end tag#Translingual

(computing) In HTML and XML, encloses a start tag that must be closed by an end tag. See < > for more information.


`lt` /`gt`

<br/>

Unsupported titles/Enclosing less than greater than

(computing) Encloses a standalone XML tag. Compare < >.


pi ~= 3.14

(programming) The inequality operator (compare ≠, !=, <>) in some programming languages, including Lua and MATLAB.


Start Graph by choosing Insert ⇨ Object to display the Object dialog box, choosing Microsoft Graph Chart from the Create New Tab, and then clicking OK.

2003, David Angell, Peter Kent, Word 2003 Bible (in English), John Wiley & Sons, →ISBN, page 553:

(computing) Alternative form of → (“indicates a series of steps to achieve a task in software”)


-`gt`

(programming) Arrow operator. Used to access class, structure or union members using a pointer.


The 🗖 button expands a window so that it fills the whole screen.

2006, Steve Rickaby, Pass ECDL in 30 Steps (in English), Cengage Learning EMEA, →ISBN, page 92:

(graphical user interface) Used as an icon to maximize a window.


The 🗕 button collapses a window into the taskbar.

(graphical user interface) Used as an icon to minimize a window.


The 🗗 button restores a window to its original size after 🗖 is used.

(graphical user interface) Used as an icon to cause a maximized window to be of a smaller, non-maximized size, possibly overlapping other windows if they exist.


(graphical user interface) Used as an icon to close an application window.


kBd

(computing) Symbol for kilobaud, a unit of data transfer rate equal to 10³ baud.


(graphical user interface) An icon to create a new (blank) file or document.


Designed after the physical buttons used on older radios to select preset stations – when one of the buttons was pressed, other buttons would pop out, leaving the pressed button the only button in the "pushed in" position.

(graphical user interface, usually found on the Internet) The radio button, which usually comes in groups (sets of multiple radio buttons), each one corresponding to an exclusive option, from which only one may be chosen. When a radio button is pressed, any previously selected radio button is automatically un-selected.


(group theory, uncommon) Denotes the graphical equality of two strings of symbols.


(mathematics) Neither approximately nor actually equal to.

Assume that ΔABC ≇ ΔDEF. Then a pair of corresponding angles, say A and D, is not congruent.

2021, Barbara E. Reynolds, William E. Fenton, College Geometry with GeoGebra (in English), John Wiley & Sons, →ISBN, page 77:

Similarly, if one can prove that there is no one-to-one correspondence between the groups, manifestly they are not isomorphic. For instance, each group of fourth order is either isomorphic to the Klein group V or to the group of square rotation R₄, while V ≇ R₄.

2015, Vladimir Lepetic, Principles of Mathematics: A Primer (in English), John Wiley & Sons, →ISBN, page 399:


(mathematics, computer science) no assignment


(computing, APL): The alpha symbol, used to format numbers as a string


◺ABC

A right triangle with vertices named A, B, and C in order.


◻ABCD

(geometry) A quadrilateral, usually referred to a square or rectangle.


◿ABC


▱ABCD

A parallelogram with vertices named A, B, C, and D in order.


(geometry) used in Arabic script to indicate the radius of a circle


⟨ ⟩ (English symbol name angle brackets)

(mathematics) Encloses the inner product of two vectors.

expectation value
expectation value#English

(mathematics) Denotes the expectation value of something.


(mathematics) Indicates the use of nearest integer function.


(computing, dated) ISO 2047 symbol for Null


(computing, dated) ISO 2047 symbol for Device Control 3


(computing, dated) ISO 2047 symbol for Device Control 4


(computing, dated) ISO 2047 symbol for Device Control 2


(computing, dated) ISO 2047 symbol for Device Control 1


(computing, dated) ISO 2047 symbol for Vertical Tabulation


(computing, dated) ISO 2047 symbol for End of Medium


(computing, dated) ISO 2047 symbol for Group Separator


(computing, dated) ISO 2047 symbol for File Separator


(computing, dated) ISO 2047 symbol for Record Separator


(computing, dated) ISO 2047 symbol for Unit Separator


(mathematics, physics) A vector pointing out of the page.

(mathematics) The Hadamard product between two matrices.

(computing, dated) ISO 2047 symbol for Shift In.


(computing, dated) ISO 2047 symbol for Bell


(computing, dated) ISO 2047 symbol for End of Transmission Block


(computing, dated) ISO 2047 symbol for Form Feed


(mathematics, physics) A double back prime. Used i.a. to mark the Riesz potential, e.g. ⟨s‶(x)⟩.


Since deformation manifests itself as a change in the metric characteristics of continuum, in the theory of finite deformations, it is then necessary to compare the referential ‵g_(ασ) and the convective g_(ασ) metrics. We systematically employ Latin indices in order to refer to spatial components of geometrical objects, whereas Greek indices to point on convective components (only a few instances can be found in the present study) or referential components (additionally, root symbol is sometimes supplied by backprime).

2023, Yuri N. Radayev, “Two-Point Rotations in Geometry of Finite Deformations”, in Holm Altenbach, Suren Manuk Mkhitaryan, Vahram Hakobyan, Avetik Varazdat Sahakyan, editors, Solid Mechanics, Theory of Elasticity and Creep (Advanced Structured Materials), Cham: Springer, →ISBN, page 276:


ex falso quod libet

(logic) The principle or axiom of logic stating that if a contradiction or a false proposition is proven to be true, then it proves that everything is true. In symbols: ⊥→P


Coordinate term: □

[…] obtained by adding the standard modal operators □ (necessity) and ◇ (possibility) to paralogics.


For example, given the equation (x − a)(x − c) = 0, if it's been shown that x − c ≠ 0, one might then write
(x − a)(x − c) = 0 ⇝ x − a = 0.

(mathematics) leads to (a conclusion); the next step (in an algorithm or in solving a problem).

For example, in a directed graph u ⇝ v means v is reachable from u, for vertices u and v.

For example, x₁ ⇝ x₀, where x₀ and x₁ are two points of a topological space, and x₀ ∈ {x₁} (every open neighborhood of x₀ contains x₁).


ternary operator
ternary operator#English


∇²

differential operator
differential operator

(mathematics) the Laplacian differential operator; the divergence of the gradient


∇ + × (formal cross product of "∇" with a function)

(mathematics) the curl differential operator


∇ + ⋅ (formal dot product of "∇" with a function)

differential operator
differential operator#English

(mathematics) The divergence differential operator.


.png

From English PNG, which is an initialization of the word Portable Network Graphics.


(mathematics) A symbol used to denote a relation between mathematical objects. There is no universally agreed upon meaning, so often the symbol is defined specifically by the author of the text. Due to its visual similarity to the subset symbol (⊂), it is most often used to denote a partial order. In LaTeX, it is typeset with \sqsubset.


(mathematics) ⊑ symbol represents a partial order relation.


(chemistry, obsolete) calcium ("lime", Daltonian symbol)

Technically, this should be red: ⊚. May also be typeset ⦾ or ◎, depending on which character matches the size of the other elements.


(mathematics)
(copyright law): No derivative work.


(chemistry, obsolete) magnesium ("magnesia", Daltonian symbol)


(mathematics) In model theory, a structure does not model a formula.

(mathematics) In proof theory, a set of formulas does not force a formula to be true.


(computing) Indicates that the number that follows is in binary.


(rare, computing) Alternative form of 0b


.gif

From English GIF, which is an initialization of Graphics Interchange Format.


(computing) Indicates that the number that follows is in octal.


(rare, computing) Alternative form of 0x


.jpeg

From English JPEG (“Joint Photographic Experts Group”).

der

(computing) An extension for JPEG files.


(rare, computing) Alternative form of 0o


.jpe

From English .jpeg, modified to fit the three-letter file extension format at the time.


(mathematics) An operator indicating special-defined operation that is similar to "element of".


(mathematics) Alternative form of ∉ (“not an element of”)


irrational number
irrational number#English

(mathematics) Representing continuation of a predictable pattern, omitted medial members of a series, indefinite continuation of an irrational number, etc. The symbol is not formally defined and approximates to the vertical equivalent of the use of the ellipsis in ordinary language.


(mathematics) Representing continuation of a predictable pattern, omitted medial members of a series, indefinite continuation of an irrational number, etc. The symbol is not formally defined and approximates to the use of the ellipsis in ordinary language.


(mathematics) An operator indicating special-defined operation that is similar to "contains".


(mathematics) A Z notation operator indicating special-defined operation.


(mathematics) Alternative form of ∌ (“does not contain”)


From the trademark "NE2000", from the Novell product. From k/K being the symbolic abbreviation of 1000.

(computing, telecommunications, countable) An ethernet network card compatible with the Novell NE2000

(computing, telecommunications, uncountable) A defacto industry standard for ethernet network cards, which implement compatibility with the Novell NE2000


From the trademark "NE1000", from the Novell product. From k/K being the symbolic abbreviation of 1000.

(computing, telecommunications, countable) An ethernet network card compatible with the Novell NE1000

(computing, telecommunications, uncountable) A defacto industry standard for ethernet network cards, which implement compatibility with the Novell NE1000


arccsc

(mathematics) The inverse cosecant, or arccosecant, function.


arccot

(mathematics) The inverse cotangent, or arccotangent, function.


.JNG

From English JNG, which is an initialization of the word JPEG Network Graphics.


.MNG

From English MNG, which is an initialization of the word Multiple-image Network Graphics.


FODG

From FODG, which is an initialization of the term Flat XML ODF Graphics.

(computing) An ODF extension for graphics files.


FODP

From FODP, which is an initialization of the term Flat XML ODF Presentations.

(computing) An ODF extension for presentation files.


FODS

From FODS, which is an initialization of the term Flat XML ODF Spreadsheets.

(computing) An ODF extension for spreadsheet files.


FODT

From FODT, which is an initialization of the term Flat XML ODF Text Documents.

(computing) An ODF extension for text or word processing files.


X̄

(mathematics) Arithmetic mean in statistics.


H₀

Si voglia, ora, verificare l’ipotesi nulla H'''₀ : μ = μ₀ contro l’alternativa H₁ : μ < μ₀.

2008, Giuseppe Cicchitelli, Statistica. Principi e metodi (in Italian), Pearson, →ISBN, →OCLC, page 445:

Let us now test the null hypothesis H'''₀ : μ = μ₀ against the alternative H₁ : μ < μ₀.

I型错误又称第I类错误，指拒绝了实际上成立的H'''₀，为“弃真”的错误，发生概率为α(即检验水准)。

2018 August 1, Shen Bicheng (沈必成), Zuo Qiang (左强), 预防医学 [Preventative Medicine] (in Chinese), Beijing Book Co. Inc., →ISBN, →OCLC:

Type I error, also known as Class I error, is an error that rejects H'''₀, which actually holds, and is "discarded while true" with a probability of α (i.e., the significance level).


head

` (English name backtick or backquote or backprime)

backtick (English name)
backquote (English name)
backprime (English name)

(dated, computing) Alternative form of ‘ (quotation mark)

The echo and sed commands appear within backprimes (`) that indicate command substitution: The result of executing the commands within the backprimes replaces the backprimes and everything between them.

1997, Mark G. Sobell, “The TC Shell”, in A Practical Guide to Linux, Reading, MA: Addison-Wesley, →ISBN, page 440:

(computing) Used as an enclosing construct in some programming languages


Coordinate term: ◌⃗

(linear algebra) Used to indicate a unit vector.

(statistics) Used to denote an estimator or an estimated value.


special unitary group
special unitary group#English

quantum chromodynamics
quantum chromodynamics#English

(mathematics) The eight-fold way; The special unitary group of order 3 (The symmetry of three-degrees of freedom (3df) of groups of three). The mathematical category in which the RGB and CMY color systems falls within, and quantum chromodynamics (“QCD”)'s symmetry group.


(mathematics)
(linguistics) Used in ⫽ ⫽.


(computing) Marks the beginning of a block of ruby text.


(computing) Separates characters that each bear ruby characters.


`gt``gt``gt`

Alternative form: ⋙

(programming) The right shift operator in some programming languages.

(mathematics) Alternative form of ⋙ (very much greater than).


`lt``lt`

Alternative form: ≪

(programming) The left shift operator in some programming languages.

(mathematics) Alternative form of ≪ (much less than).


`gt``gt`

Alternative form: ≫

(mathematics) Alternative form of ≫ (much greater than).


`lt``lt``lt`

Alternative form: ⋘

(mathematics) Alternative form of ⋘ (very much less than).


a⃗ + (-a⃗) = 0

Coordinate term: ◌̂

(linear algebra, physics) Denotes a vector quantity.


[🔎 appears to the left of the search box.]

graphical user interface
graphical user interface

(graphical user interface) An icon to search something.

(graphical user interface) An icon to zoom in or enlarge content.


[This system-wide desktop search feature for macOS and iOS uses a left-leaning magnifying glass as its search icon.]

You can also use the Search function (🔍) to look for interesting events or places with their associated teleport links, maps, and information.

2022 December 5, Julian Chen, Second Life as a Virtual Playground for Language Education: A Practical Guide for Teaching and Research (in English), Taylor & Francis, →ISBN, unnumbered page:


𝕏

Ultimately derived from x (“name for an unknown variable”), by analogy with other blackboard bold mathematical symbols; see blackboard bold § usage on WikipediaWikipedia.

pedia

(mathematics) Used to denote an arbitrary metric space.


(graphical user interface) Represents a user profile or contact.


(graphical user interface) Represents multiple user profiles or contacts.


(graphical user interface, Internet) A shopping cart or basket.


(computing) An icon that increases the brightness of a screen.


(graphical user interface) An icon that indicates the battery percentage of a computer or mobile device.


(computing) An icon that decreases the brightness of a screen.


(graphical user interface, Internet slang) To pin. (“To attach (an icon, application, message etc.) to another item so that it persists.”)


\n

From the escape sequence used in the C programming language and its numerous derivatives.

(programming) A representation of the newline character.


\t

(programming) A representation of the tab character.


\r

(programming) A representation of the carriage return character.


\b

(programming) A representation of the backspace character.


\f

(programming) A representation of the form feed character.


\v

(programming) A representation of the vertical tab character.


Alternative form: \000

(programming) A representation of the null character.


\a

From the escape sequence used in the C programming language and its numerous derivatives; from \ (escape character) + an initialism of alert.

(programming) A representation of the bell character.


In the Settings app, tap the switch next to Airplane Mode. You see an airplane ✈ icon in the top status bar when the mode is active. (When you turn the mode on or off, the airplane ✈ icon cutely flies in or out.)

2023 September 18, Glenn Fleishman, “Manage Airplane Mode”, in Take Control of iOS & iPadOS Privacy and Security, 4 edition (in English), alt concepts^([sic]), →ISBN:

(graphical user interface) Airplane mode.


On iOS's e-mail client, unread e-mails are marked with 🔵 at the top left fronting the subject title.

On Telegram, unread messages are denoted with 🔵 at their right.

(computing, social media) An unread notification, message or e-mail.


🟡 Single-click the yellow button to minimize the window, which sends a tiny icon down into the Dock, on the right side.

2010, Robin Williams, John Tollett, Mac OS X 10.6 Snow Leopard (in English), Peachpit Press, →ISBN, page 9:

(graphical user interface) On Apple Mac computers, a button that when pressed minimises a window.

(graphical user interface, social media) AFK; idle; inactive.


(graphical user interface, mobile telephony) On iPhones and iPadOS, indicates that the microphone is activated.


(graphical user interface, proscribed) A button that when pressed displays the previous page.

The red dot on your Apple Watch is a signal that shows you have unread notifications. These can be anything from calls and texts to push notifications from apps, like somebody liking your post on Facebook or requesting to follow you on Instagram.

2023 January 10, Sarah Vincent, “What Is That Red Dot on Your Apple Watch—and How Do You Get Rid of It?”, in Reader's Digest (in English):

(graphical user interface, social media) An unread notification.


(computing, Internet) Indicates an action has occurred; success, completed.

(graphical user interface) A button that when pressed opens a page or webpage; or, enables full screen mode.

(graphical user interface, social media) Online; active; available.

(graphical user interface, mobile telephony) On iPhones and iPadOS, indicates that the camera is enabled.


`lcub``rcub`

(set theory) Alternative form of { } (“the empty set”)


.kar

The KDE MIDI/Karaoke file player allows you to play .mid and .kar files if your sound card has hardware support for raw MIDI files.

2006, Michael Jang, Mastering Red Hat Linux 9, page 529:

(computing) An extension for MIDI "karaoke" files.


ℵ₁

continuum hypothesis
continuum hypothesis

(mathematics, set theory) the second of the transfinite cardinal numbers; according to the continuum hypothesis, it corresponds to the number of real numbers.


n**2 = n² = n × n


From the fact that the C programming language states that a character escape sequence may consist of a maximum of three octal digits; if the shorter sequence \0 is followed by an octal digit which is intended to represent the next character, then \000 is required to prevent that digit from being interpreted as part of the escape sequence instead. For example, \0 followed by 1 would be interpreted as the escape sequence \01, whereas \0001 is interpreted as \000 followed by the digit 1.

(programming) Alternative form of \0 (null character).


(mathematics) [is or are] approximately or exactly equal to


(graphical user interface) Used as an icon for a text file.


ℱ

(mathematics) The set of functions. Usually used in the form ℱ(X,ℂ) to denote the set of functions whose domain is a relatively arbitrary set X and whose codomain is the set of complex numbers.


🔍 Search – 👤 Profile – 📰 News – ⚙ Settings

(graphical user interface, metonymically) News.


(graphical user interface) An icon that when pressed takes the user to the home page.


(computing, graphical user interface) A button to refresh (reload) a document.

(graphical user interface) Indicates that a command or task is in progress; loading.


(computing) beginning of page/document, home


(computing) Option key on Apple Macintosh computer keyboards.


(computing) Turns a device on or off without disconnecting the power supply; sleep mode.

(Internet, graphical user interface) Login; logout.

(Internet, graphical user interface, uncommon) Closes or exits an application or webpage.


(computing) Turns a device on or off by fully disconnecting the power supply.


(linear algebra, physics) Denotes a tensor quantity.