Complement may refer to:

The arts

* Complement (music), an interval that, when added to another, spans an octave ** Aggregate complementation, the separation of pitch-class collections into complementary sets * Complementary color, in the visual arts

Biology and medicine

* Complement system (immunology), a cascade of proteins in the blood that form part of innate immunity * Complementary DNA, DNA reverse transcribed from a mature mRNA template * Complementarity (molecular biology), a property whereby double stranded nucleic acids pair with each other * Complementation (genetics), a test to determine if independent recessive mutant phenotypes are caused by mutations in the same gene or in different genes

Grammar and linguistics

Complement (linguistics) In grammar, a complement is a word, phrase, or clause that is necessary to complete the meaning of a given expression. Complements are often also arguments (expressions that help complete the meaning of a predicate). Predicative, subject and ob ...

, a word or phrase having a particular syntactic role ** Subject complement, a word or phrase adding to a clause's subject after a linking verb ** Object complement, a word or phrase adding to the direct object of a verb phrase. * Phonetic complement * Complementary, a type of opposite in lexical semantics (sometimes called an antonym)

Mathematics

Algebra

* Complement (group theory) * Complementary subspaces * Orthogonal complement * Schur complement

Algorithms

* Complement (complexity), relating to decision problems and complexity classes *

Complement operator (regular expressions) A regular expression (shortened as regex or regexp), sometimes referred to as rational expression, is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" ...

* Method of complements, in computer science ** Radix complement ** Diminished radix complement **

Ones' complement The ones' complement of a binary number is the value obtained by inverting (flipping) all the bits in the Binary number, binary representation of the number. The name "ones' complement" refers to the fact that such an inverted value, if added t ...

** Two's complement

Discrete mathematics

Complement graph In the mathematical field of graph theory, the complement or inverse of a graph is a graph on the same vertices such that two distinct vertices of are adjacent if and only if they are not adjacent in . That is, to generate the complement of ...

Self-complementary graph In the mathematical field of graph theory, a self-complementary graph is a graph which is isomorphic to its complement. The simplest non-trivial self-complementary graphs are the path graph and the cycle graph. There is no known characteri ...

, a graph which is isomorphic to its complement *

Complemented lattice In the mathematics, mathematical discipline of order theory, a complemented lattice is a bounded lattice (order), lattice (with least element 0 and greatest element 1), in which every element ''a'' has a complement, i.e. an element ''b'' satisfyin ...

Geometry

* Complement of an angle, the difference between a right angle (90 degrees) and a given angle *

Knot complement In mathematics, the knot complement of a tame knot ''K'' is the space where the knot is not. If a knot is embedded in the 3-sphere, then the complement is the 3-sphere minus the space near the knot. To make this precise, suppose that ''K'' is a ...

* Complement of a point, the dilation of a point in the

centroid In mathematics and physics, the centroid, also known as geometric center or center of figure, of a plane figure or solid figure is the arithmetic mean position of all the points in the figure. The same definition extends to any object in n-d ...

of a given triangle, with ratio −1/2

Logic

Complement (set theory) In set theory, the complement of a Set (mathematics), set , often denoted by A^c (or ), is the set of Element (mathematics), elements not in . When all elements in the Universe (set theory), universe, i.e. all elements under consideration, are c ...

Complementary event In probability theory, the complement of any event ''A'' is the event ot ''A'' i.e. the event that ''A'' does not occur.Robert R. Johnson, Patricia J. Kuby: ''Elementary Statistics''. Cengage Learning 2007, , p. 229 () The event ''A'' and ...

in probability *

Logical complement In logic, negation, also called the logical not or logical complement, is an operation that takes a proposition P to another proposition "not P", written \neg P, \mathord P, P^\prime or \overline. It is interpreted intuitively as being true ...

Bitwise complement In computer programming, a bitwise operation operates on a bit string, a bit array or a binary numeral (considered as a bit string) at the level of its individual bits. It is a fast and simple action, basic to the higher-level arithmetic operatio ...

* Complements in

boolean algebra In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variable (mathematics), variables are the truth values ''true'' and ''false'', usually denot ...

Other uses

* Complementary experiments, in physics * Complement good (economics), a good often consumed together with another good * Ship's complement, the number of persons in a ship's company