158 relations: AC (complexity), Adjacency list, Adjacency matrix, Age of the universe, Alan Turing, Algorithm, ALL (complexity), Alphabet (formal languages), Alternating Turing machine, Analysis of algorithms, Arthur–Merlin protocol, Best, worst and average case, Big O notation, Binary number, Biology, Bit array, Blum axioms, Blum's speedup theorem, Boolean circuit, Boolean satisfiability problem, Boris Trakhtenbrot, BPP (complexity), BQP, Cambridge University Press, Cellular automaton, Cengage Learning, Church–Turing thesis, Circuit complexity, Clay Mathematics Institute, Co-NP, Cobham's thesis, Combinatorics, Communication complexity, Complement (complexity), Complete (complexity), Complexity, Complexity class, Computability theory, Computational problem, Computer, Connectivity (graph theory), Context of computational complexity, Conway's Game of Life, Counting problem (complexity), Decision problem, Decision tree model, Descriptive complexity theory, Deterministic algorithm, Discrete logarithm, DSPACE, ..., DTIME, Euclidean algorithm, Eugene M. Luks, EXPSPACE, EXPTIME, Formal language, FP (complexity), Function problem, Gabriel Lamé, Game complexity, General number field sieve, Graph (mathematics), Graph isomorphism, Graph isomorphism problem, Graph theory, Hamiltonian path problem, Hisao Yamada, Integer, Integer factorization, Integer programming, Interactive proof system, Intractability, Introduction to Automata Theory, Languages, and Computation, Introduction to the Theory of Computation, IP (complexity), Jack Edmonds, John Myhill, John Wiley & Sons, Knapsack problem, L (complexity), Lance Fortnow, László Babai, Leonid Levin, Linear bounded automaton, List of complexity classes, List of computability and complexity topics, List of important publications in theoretical computer science, List of unsolved problems in computer science, Log-space reduction, Logic gate, Logistics, Manuel Blum, Mathematics, Milan, Millennium Prize Problems, Minimax, MIT Press, Model of computation, Multiplication, NC (complexity), NEXPTIME, NL (complexity), Non-deterministic Turing machine, Nondeterministic algorithm, NP (complexity), NP-completeness, NP-hardness, NP-intermediate, NSPACE, NTIME, Operations research, Optimization problem, P (complexity), Parallel computing, Parameterized complexity, Partial function, Polynomial hierarchy, Polynomial-time reduction, PP (complexity), Presburger arithmetic, Primality test, Probabilistic Turing machine, Probability distribution, Promise problem, Proof complexity, Protein structure prediction, PSPACE, Pure mathematics, QMA, Quantum algorithm, Quantum complexity theory, Quantum Turing machine, Quicksort, Random-access machine, Randomized algorithm, Raymond Smullyan, Richard M. Karp, RP (complexity), RSA (cryptosystem), Savitch's theorem, Sharp-P, Shor's algorithm, Space hierarchy theorem, Springer Science+Business Media, Stephen Cook, String (computer science), Structural complexity theory, Symmetric Turing machine, Symposium on Theoretical Aspects of Computer Science, Theoretical computer science, Theory of computation, Time complexity, Time hierarchy theorem, Transcomputational problem, Travelling salesman problem, Turing machine, Vertex cover, ZPP (complexity). Expand index (108 more) » « Shrink index
In circuit complexity, AC is a complexity class hierarchy.
In graph theory and computer science, an adjacency list representation of a graph is a collection of unordered lists, one for each vertex in the graph.
In mathematics, computer science and application areas such as sociology, an adjacency matrix is a means of representing which vertices (or nodes) of a graph are adjacent to which other vertices.
In physical cosmology, the age of the universe is the time elapsed since the Big Bang.
Alan Mathison Turing, OBE, FRS (23 June 1912 – 7 June 1954) was a British pioneering computer scientist, mathematician, logician, cryptanalyst, theoretical biologist, and marathon and ultra distance runner.
In mathematics and computer science, an algorithm is a self-contained step-by-step set of operations to be performed.
In computability and complexity theory, ALL is the class of all decision problems.
In formal language theory, a non-empty set is called alphabet when its intended use in string operations shall be indicated.
In computational complexity theory, an alternating Turing machine (ATM) is a non-deterministic Turing machine (NTM) with a rule for accepting computations that generalizes the rules used in the definition of the complexity classes NP and co-NP.
In computer science, the analysis of algorithms is the determination of the amount of resources (such as time and storage) necessary to execute them.
In computational complexity theory, an Arthur–Merlin protocol is an interactive proof system in which the verifier's coin tosses are constrained to be public (i.e. known to the prover too).
In computer science, best, worst, and average cases of a given algorithm express what the resource usage is at least, at most and on average, respectively.
In mathematics, big O notation describes the limiting behavior of a function when the argument tends towards a particular value or infinity, usually in terms of simpler functions.
In mathematics and digital electronics, a binary number is a number expressed in the binary numeral system, or base-2 numeral system, which represents numeric values using two different symbols: typically 0 (zero) and 1 (one).
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy.
A bit array (also known as bitmap, bitset, bit string, or bit vector) is an array data structure that compactly stores bits.
In computational complexity theory the Blum axioms or Blum complexity axioms are axioms that specify desirable properties of complexity measures on the set of computable functions.
In computational complexity theory Blum's speedup theorem, first stated by Manuel Blum in 1967, is a fundamental theorem about the complexity of computable functions.
In computational complexity theory and circuit complexity, a Boolean circuit is a mathematical model for digital logic circuits.
In computer science, the Boolean Satisfiability Problem (sometimes called Propositional Satisfiability Problem and abbreviated as SATISFIABILITY or SAT) is the problem of determining if there exists an interpretation that satisfies a given Boolean formula.
Boris (Boaz) Avraamovich Trakhtenbrot (Борис Авраамович Трахтенброт; born 19 February 1921 in Brichevo, northern Bessarabia) or Boaz (Boris) Trakhtenbrot (בועז טרכטנברוט) is an Israeli and Russian mathematician in mathematical logic, algorithms, theory of computation and cybernetics.
In computational complexity theory, BPP, which stands for bounded-error probabilistic polynomial time is the class of decision problems solvable by a probabilistic Turing machine in polynomial time with an error probability bounded away from 1/3 for all instances.
In computational complexity theory, BQP (bounded error quantum polynomial time) is the class of decision problems solvable by a quantum computer in polynomial time, with an error probability of at most 1/3 for all instances.
Cambridge University Press (CUP) is the publishing business of the University of Cambridge.
A cellular automaton (pl. cellular automata, abbrev. CA) is a discrete model studied in computability theory, mathematics, physics, complexity science, theoretical biology and microstructure modeling.
Cengage Learning, Inc. is an educational content, technology, and services company for the higher education and K-12, professional and library markets worldwide.
In computability theory, the Church–Turing thesis (also known as the Turing–Church thesis, the Church–Turing conjecture, Church's thesis, Church's conjecture, and Turing's thesis) is a hypothesis ("thesis") about the nature of computable functions.
In theoretical computer science, circuit complexity is a branch of computational complexity theory in which Boolean functions are classified according to the size or depth of Boolean circuits that compute them.
The Clay Mathematics Institute (CMI) is a private, non-profit foundation, based in Providence, Rhode Island.
In computational complexity theory, co-NP is a complexity class.
Cobham's thesis, also known as Cobham–Edmonds thesis (named after Alan Cobham and Jack Edmonds), asserts that computational problems can be feasibly computed on some computational device only if they can be computed in polynomial time; that is, if they lie in the complexity class P. Formally, to say that a problem can be solved in polynomial time is to say that there exists an algorithm that, given an n-bit instance of the problem as input, can produce a solution in time O(nc), where c is a constant that depends on the problem but not the particular instance of the problem.
Combinatorics is a branch of mathematics concerning the study of finite or countable discrete structures.
The notion of communication complexity was introduced by Yao in 1979, who investigated the following problem involving two separated parties (Alice and Bob).
In computational complexity theory, the complement of a decision problem is the decision problem resulting from reversing the yes and no answers.
In computational complexity theory, a computational problem is complete for a complexity class if it is, in a technical sense, among the "hardest" (or "most expressive") problems in the complexity class.
There is no absolute definition of what complexity means; the only consensus among researchers is that there is no agreement about the specific definition of complexity.
In computational complexity theory, a complexity class is a set of problems of related resource-based complexity.
Computability theory, also called recursion theory, is a branch of mathematical logic, of computer science, and of the theory of computation that originated in the 1930s with the study of computable functions and Turing degrees.
In theoretical computer science, a computational problem is a mathematical object representing a collection of questions that computers might be able to solve.
A computer is a general-purpose device that can be programmed to carry out a set of arithmetic or logical operations automatically.
In mathematics and computer science, connectivity is one of the basic concepts of graph theory: it asks for the minimum number of elements (nodes or edges) that need to be removed to disconnect the remaining nodes from each other.
In computational complexity theory and analysis of algorithms, a number of metrics are defined describing the resources, such as time or space, that a machine needs to solve a particular problem.
The Game of Life, also known simply as Life, is a cellular automaton devised by the British mathematician John Horton Conway in 1970.
In computational complexity theory and computability theory, a counting problem is a type of computational problem.
In computability theory and computational complexity theory, a decision problem is a question in some formal system with a yes-or-no answer, depending on the values of some input parameters.
In computational complexity and communication complexity theories the decision tree model is the model of computation or communication in which an algorithm or communication process is considered to be basically a decision tree, i.e., a sequence of branching operations based on comparisons of some quantities, the comparisons being assigned the unit computational cost.
Descriptive complexity is a branch of computational complexity theory and of finite model theory that characterizes complexity classes by the type of logic needed to express the languages in them.
In computer science, a deterministic algorithm is an algorithm which, given a particular input, will always produce the same output, with the underlying machine always passing through the same sequence of states.
In mathematics, a discrete logarithm is an integer k solving the equation, where b and g are elements of a finite group.
In computational complexity theory, DSPACE or SPACE is the computational resource describing the resource of memory space for a deterministic Turing machine.
In computational complexity theory, DTIME (or TIME) is the computational resource of computation time for a deterministic Turing machine.
. EXAMPLES CAN BE FOUND BELOW, E.G., IN THE "Matrix method" SECTION.
Eugene Michael Luks (born circa 1940) is an American mathematician and computer scientist, a professor emeritus of computer and information science at the University of Oregon.
In complexity theory, EXPSPACE is the set of all decision problems solvable by a deterministic Turing machine in O(2p(n)) space, where p(n) is a polynomial function of n. (Some authors restrict p(n) to be a linear function, but most authors instead call the resulting class ESPACE.) If we use a nondeterministic machine instead, we get the class NEXPSPACE, which is equal to EXPSPACE by Savitch's theorem.
In computational complexity theory, the complexity class EXPTIME (sometimes called EXP or DEXPTIME) is the set of all decision problems solvable by a deterministic Turing machine in O(2p(n)) time, where p(n) is a polynomial function of n. In terms of DTIME, We know and also, by the time hierarchy theorem and the space hierarchy theorem, that so at least one of the first three inclusions and at least one of the last three inclusions must be proper, but it is not known which ones are.
In mathematics, computer science, and linguistics, a formal language is a set of strings of symbols that may be constrained by rules that are specific to it.
In computational complexity theory, the complexity class FP is the set of function problems which can be solved by a deterministic Turing machine in polynomial time; it is the function problem version of the decision problem class P. Roughly speaking, it is the class of functions that can be efficiently computed on classical computers without randomization.
In computational complexity theory, a function problem is a computational problem where a single output (of a total function) is expected for every input, but the output is more complex than that of a decision problem, that is, it isn't just YES or NO.
Gabriel Léon Jean Baptiste Lamé (22 July 1795 – 1 May 1870) was a French mathematician who contributed to the theory of partial differential equations by the use of curvilinear coordinates, and the mathematical theory of elasticity.
Combinatorial game theory has several ways of measuring game complexity.
In number theory, the general number field sieve (GNFS) is the most efficient classical algorithm known for factoring integers larger than 100 digits.
In mathematics, and more specifically in graph theory, a graph is a representation of a set of objects where some pairs of objects are connected by links.
In graph theory, an isomorphism of graphs G and H is a bijection between the vertex sets of G and H such that any two vertices u and v of G are adjacent in G if and only if ƒ(u) and ƒ(v) are adjacent in H. This kind of bijection is generally called "edge-preserving bijection", in accordance with the general notion of isomorphism being a structure-preserving bijection.
The graph isomorphism problem is the computational problem of determining whether two finite graphs are isomorphic.
In mathematics and computer science, graph theory is the study of graphs, which are mathematical structures used to model pairwise relations between objects.
In the mathematical field of graph theory the Hamiltonian path problem and the Hamiltonian cycle problem are problems of determining whether a Hamiltonian path (a path in an undirected or directed graph that visits each vertex exactly once) or a Hamiltonian cycle exists in a given graph (whether directed or undirected).
was a Japanese computer scientist, known for his influential contributions to theoretical computer science, as well as for the development of Japanese keyboard layouts, a challenging practical problem.
An integer (from the Latin ''integer'' meaning "whole")Integer 's first, literal meaning in Latin is "untouched", from in ("not") plus tangere ("to touch").
In number theory, integer factorization is the decomposition of a composite number into a product of smaller integers.
An integer programming problem is a mathematical optimization or feasibility program in which some or all of the variables are restricted to be integers.
In computational complexity theory, an interactive proof system is an abstract machine that models computation as the exchange of messages between two parties.
Intractable is an adjective describing high complexity, which makes it difficult to change, manipulate, or resolve an issue.
Introduction to Automata Theory, Languages, and Computation is an influential computer science textbook by John Hopcroft and Jeffrey Ullman on formal languages and the theory of computation.
Introduction to the Theory of Computation (ISBN 0-534-95097-3) is a standard textbook in theoretical computer science, written by Michael Sipser and first published by PWS Publishing in 1997.
In computational complexity theory, the class IP (which stands for Interactive Polynomial time) is the class of problems solvable by an interactive proof system.
Jack R. Edmonds (born April 5, 1934) is an American computer scientist, regarded as one of the most important contributors to the field of combinatorial optimization.
John R. Myhill, Sr. (11 August 1923 – 15 February 1987) was a British mathematician.
John Wiley & Sons, Inc., also referred to as Wiley, is a global publishing company that specializes in academic publishing and markets its products to professionals and consumers, students and instructors in higher education, and researchers and practitioners in scientific, technical, medical, and scholarly fields.
The knapsack problem or rucksack problem is a problem in combinatorial optimization: Given a set of items, each with a mass and a value, determine the number of each item to include in a collection so that the total weight is less than or equal to a given limit and the total value is as large as possible.
In computational complexity theory, L (also known as LSPACE or DLOGSPACE) is the complexity class containing decision problems that can be solved by a deterministic Turing machine using a logarithmic amount of memory space.
Lance Jeremy Fortnow (born August 15, 1963) is a computer scientist known for major results in computational complexity and interactive proof systems.
László (Laci) Babai (born July 20, 1950 in Budapest) from Babai's web site, retrieved 2010-07-30.
Leonid Anatolievich Levin (Леони́д Анато́льевич Ле́вин; Леоні́д Анато́лійович Ле́він; born November 2, 1948) is a Soviet-American computer scientist.
In computer science, a linear bounded automaton (plural linear bounded automata, abbreviated LBA) is a restricted form of Turing machine.
This is a list of complexity classes in computational complexity theory.
This is a list of computability and complexity topics, by Wikipedia page.
This article is a list of unsolved problems in computer science.
In computational complexity theory, a log-space reduction is a reduction computable by a deterministic Turing machine using logarithmic space.
In electronics, a logic gate is an idealized or physical device implementing a Boolean function; that is, it performs a logical operation on one or more logical inputs, and produces a single logical output.
Logistics is the management of the flow of things between the point of origin and the point of consumption in order to meet requirements of customers or corporations.
Manuel Blum (Caracas, 26 April 1938) is a Venezuelan computer scientist who received the Turing Award in 1995 "In recognition of his contributions to the foundations of computational complexity theory and its application to cryptography and program checking".
Mathematics (from Greek μάθημα máthēma, “knowledge, study, learning”) is the study of topics such as quantity (numbers), structure, space, and change.
Milan (or; Milano; Milanese: Milan), the second-most populous city in Italy, serves as the capital of Lombardy.
The Millennium Prize Problems are seven problems in mathematics that were stated by the Clay Mathematics Institute in 2000.
Minimax (sometimes MinMax or MM) is a decision rule used in decision theory, game theory, statistics and philosophy for minimizing the possible loss for a worst case (maximum loss) scenario.
The MIT Press is a university press affiliated with the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts (United States).
In computability theory and computational complexity theory, a model of computation is the definition of the set of allowable operations used in computation and their respective costs.
Multiplication (often denoted by the cross symbol "×", by a point "·" or by the absence of symbol) is one of the four elementary, mathematical operations of arithmetic; with the others being addition, subtraction and division.
In complexity theory, the class NC (for "Nick's Class") is the set of decision problems decidable in polylogarithmic time on a parallel computer with a polynomial number of processors.
In computational complexity theory, the complexity class NEXPTIME (sometimes called NEXP) is the set of decision problems that can be solved by a non-deterministic Turing machine using time 2n O(1) and unlimited space.
In computational complexity theory, NL (Nondeterministic Logarithmic-space) is the complexity class containing decision problems which can be solved by a nondeterministic Turing machine using a logarithmic amount of memory space.
In theoretical computer science, a Turing machine is a theoretical machine that is used in thought experiments to examine the abilities and limitations of computers.
In computer science, a nondeterministic algorithm is an algorithm that, even for the same input, can exhibit different behaviors on different runs, as opposed to a deterministic algorithm.
In computational complexity theory, NP is one of the most fundamental complexity classes.
In computational complexity theory, a decision problem is NP-complete when it is both in NP and NP-hard.
NP-hardness (''n''on-deterministic ''p''olynomial-time hard), in computational complexity theory, is a class of problems that are, informally, "at least as hard as the hardest problems in NP".
In computational complexity, problems that are in the complexity class NP but are neither in the class P nor NP-complete are called NP-intermediate, and the class of such problems is called NPI.
In computational complexity theory, non-deterministic space or NSPACE is the computational resource describing the memory space for a non-deterministic Turing machine.
In computational complexity theory, the complexity class NTIME(f(n)) is the set of decision problems that can be solved by a non-deterministic Turing machine which runs in time O(f(n)).
Operations research, or operational research in British usage, is a discipline that deals with the application of advanced analytical methods to help make better decisions.
In mathematics and computer science, an optimization problem is the problem of finding the best solution from all feasible solutions.
In computational complexity theory, P, also known as PTIME or DTIME(nO(1)), is one of the most fundamental complexity classes.
Parallel computing is a form/type of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved at the same time.
In computer science, parameterized complexity is a branch of computational complexity theory that focuses on classifying computational problems according to their inherent difficulty with respect to multiple parameters of the input.
In mathematics, a partial function from X to Y (written as) is a function, for some subset X′ of X.
In computational complexity theory, the polynomial hierarchy (sometimes called the polynomial-time hierarchy) is a hierarchy of complexity classes that generalize the classes P, NP and co-NP to oracle machines.
In computational complexity theory, a polynomial-time reduction is a method of solving one problem by means of a hypothetical subroutine for solving a different problem (that is, a reduction), that uses polynomial time excluding the time within the subroutine.
In complexity theory, PP is the class of decision problems solvable by a probabilistic Turing machine in polynomial time, with an error probability of less than 1/2 for all instances.
Presburger arithmetic is the first-order theory of the natural numbers with addition, named in honor of Mojżesz Presburger, who introduced it in 1929.
A primality test is an algorithm for determining whether an input number is prime.
In computability theory, a probabilistic Turing machine is a non-deterministic Turing machine which randomly chooses between the available transitions at each point according to some probability distribution.
In probability and statistics, a probability distribution assigns a probability to each measurable subset of the possible outcomes of a random experiment, survey, or procedure of statistical inference.
In computational complexity theory, a promise problem is a generalization of a decision problem where the input is promised to belong to a subset of all possible inputs.
In computer science, proof complexity is a measure of efficiency of automated theorem proving methods that is based on the size of the proofs they produce.
Protein structure prediction is the prediction of the three-dimensional structure of a protein from its amino acid sequence — that is, the prediction of its folding and its secondary, tertiary, and quaternary structure from its primary structure.
In computational complexity theory, PSPACE is the set of all decision problems that can be solved by a Turing machine using a polynomial amount of space.
Broadly speaking, pure mathematics is mathematics that studies entirely abstract concepts.
In computational complexity theory, QMA, which stands for Quantum Merlin Arthur, is the quantum analog of the deterministic complexity class NP or the probabilistic complexity class MA.
In quantum computing, a quantum algorithm is an algorithm which runs on a realistic model of quantum computation, the most commonly used model being the quantum circuit model of computation.
Quantum complexity theory is a part of computational complexity theory in theoretical computer science.
A quantum Turing machine (QTM), also a universal quantum computer, is an abstract machine used to model the effect of a quantum computer.
Quicksort (sometimes called partition-exchange sort) is an efficient sorting algorithm, serving as a systematic method for placing the elements of an array in order.
In computer science, random-access machine (RAM) is an abstract machine in the general class of register machines.
A randomized algorithm is an algorithm that employs a degree of randomness as part of its logic.
Raymond Merrill Smullyan (born May 25, 1919) is an American mathematician, concert pianist, logician, Taoist philosopher, and magician.
Richard Manning Karp (born January 3, 1935) is an American computer scientist and computational theorist at the University of California, Berkeley.
In computational complexity theory, randomized polynomial time (RP) is the complexity class of problems for which a probabilistic Turing machine exists with these properties.
RSA is one of the first practical public-key cryptosystems and is widely used for secure data transmission.
In computational complexity theory, Savitch's theorem, proved by Walter Savitch in 1970, gives a relationship between deterministic and non-deterministic space complexity.
In computational complexity theory, the complexity class #P (pronounced "number P" or, sometimes "sharp P" or "hash P") is the set of the counting problems associated with the decision problems in the set NP.
Shor's algorithm, named after mathematician Peter Shor, is a quantum algorithm (an algorithm that runs on a quantum computer) for integer factorization formulated in 1994.
In computational complexity theory, the space hierarchy theorems are separation results that show that both deterministic and nondeterministic machines can solve more problems in (asymptotically) more space, subject to certain conditions.
Springer Science+Business Media or Springer is a global publishing company that publishes books, e-books and peer-reviewed journals in science, technical and medical (STM) publishing.
Stephen Arthur Cook, (born December 14, 1939) is a renowned American-Canadian computer scientist and mathematician who has made major contributions to the fields of complexity theory and proof complexity.
In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable.
In computational complexity theory of computer science, the structural complexity theory or simply structural complexity is the study of complexity classes, rather than computational complexity of individual problems and algorithms.
A symmetric Turing machine is a Turing machine which has a configuration graph that is undirected (that is, configuration i yields configuration j if and only if j yields i).
Symposium on Theoretical Aspects of Computer Science (STACS) is an academic conference in the field of computer science.
Theoretical computer science is a division or subset of general computer science and mathematics that focuses on more abstract or mathematical aspects of computing and includes the theory of computation.
In theoretical computer science and mathematics, the theory of computation is the branch that deals with how efficiently problems can be solved on a model of computation, using an algorithm.
In computer science, the time complexity of an algorithm quantifies the amount of time taken by an algorithm to run as a function of the length of the string representing the input.
In computational complexity theory, the time hierarchy theorems are important statements about time-bounded computation on Turing machines.
In computational complexity theory, a transcomputational problem is a problem that requires processing of more than 1093 bits of information.
The travelling salesman problem (TSP) asks the following question: Given a list of cities and the distances between each pair of cities, what is the shortest possible route that visits each city exactly once and returns to the origin city? It is an NP-hard problem in combinatorial optimization, important in operations research and theoretical computer science.
A Turing machine is an abstract "machine" that manipulates symbols on a strip of tape according to a table of rules; to be more exact, it is a mathematical model that defines such a device.
In the mathematical discipline of graph theory, a vertex cover (sometimes node cover) of a graph is a set of vertices such that each edge of the graph is incident to at least one vertex of the set.
In complexity theory, ZPP (zero-error probabilistic polynomial time) is the complexity class of problems for which a probabilistic Turing machine exists with these properties.
Asymptotic complexity, Calculation complexity, Complexity of algorithms, Complexity theory (computation), Complexity theory in computation, Computational complexity analysis, Computational intractability, Computational intractablity, Computationally efficient, Computationally infeasible, Computationally intractable, Continuous complexity theory, Efficient procedure, Efficiently-computable, Feasible computability, Feasible computation, Hierarchy theorem, Input size, Intractability (complexity), Intractable problem, Intractableness, Intractably, Levin reduction, Order of complexity, Order of computation, Space complexity theory.