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

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.


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.

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


NP

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


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.


lb

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

der

lb(x)= log ₂(x). lb(2)=1

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


Π

arithmetical hierarchy
arithmetical hierarchy

polynomial hierarchy
polynomial hierarchy

universal quantifier
universal quantifier

(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.


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


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.

(computer science) class of problems solvable in polynomial time


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))


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


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.


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, computer science) Kleene plus


(mathematics, computer science) assignment


`num`

head

`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) Used to indicate string concatenation.


ℰ

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


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


(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


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.


(mathematics, computer science) no assignment