Global Information Lookup Global Information

Space hierarchy theorem information


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. For example, a deterministic Turing machine can solve more decision problems in space n log n than in space n. The somewhat weaker analogous theorems for time are the time hierarchy theorems.

The foundation for the hierarchy theorems lies in the intuition that with either more time or more space comes the ability to compute more functions (or decide more languages). The hierarchy theorems are used to demonstrate that the time and space complexity classes form a hierarchy where classes with tighter bounds contain fewer languages than those with more relaxed bounds. Here we define and prove the space hierarchy theorem.

The space hierarchy theorems rely on the concept of space-constructible functions. The deterministic and nondeterministic space hierarchy theorems state that for all space-constructible functions f(n),

,

where SPACE stands for either DSPACE or NSPACE, and o refers to the little o notation.

and 24 Related for: Space hierarchy theorem information

Request time (Page generated in 0.8458 seconds.)

Space hierarchy theorem

Last Update:

In computational complexity theory, the space hierarchy theorems are separation results that show that both deterministic and nondeterministic machines...

Word Count : 2699

Time hierarchy theorem

Last Update:

theory, the time hierarchy theorems are important statements about time-bounded computation on Turing machines. Informally, these theorems say that given...

Word Count : 2467

DSPACE

Last Update:

assumed. □ The above theorem implies the necessity of the space-constructible function assumption in the space hierarchy theorem. L = DSPACE(O(log n))...

Word Count : 1047

EXPTIME

Last Update:

time and space complexity classes in the following way: P ⊆ NP ⊆ PSPACE ⊆ EXPTIME ⊆ NEXPTIME ⊆ EXPSPACE. Furthermore, by the time hierarchy theorem and the...

Word Count : 991

Computational complexity theory

Last Update:

space requirements, the answer to such questions is given by the time and space hierarchy theorems respectively. They are called hierarchy theorems because...

Word Count : 6302

Constructible function

Last Update:

\log(n)} is a space-constructible function. Time-constructible functions are used in results from complexity theory such as the time hierarchy theorem. They are...

Word Count : 605

PSPACE

Last Update:

space hierarchy theorem, NL ⊊ NPSPACE) and the fact that PSPACE = NPSPACE via Savitch's theorem. The second follows simply from the space hierarchy theorem...

Word Count : 981

Complexity class

Last Update:

time and space hierarchy theorems form the basis for most separation results of complexity classes. For instance, the time hierarchy theorem establishes...

Word Count : 10356

Space complexity

Last Update:

_{c\in \mathbb {Z} ^{+}}{\mathsf {NSPACE}}(n^{c})} The space hierarchy theorem states that, for all space-constructible functions f ( n ) , {\displaystyle f(n)...

Word Count : 994

Arithmetical hierarchy

Last Update:

In mathematical logic, the arithmetical hierarchy, arithmetic hierarchy or Kleene–Mostowski hierarchy (after mathematicians Stephen Cole Kleene and Andrzej...

Word Count : 4582

Structural complexity theory

Last Update:

theorem states that there exists no largest complexity class, with computable boundary, which contains all computable functions. The space hierarchy theorems...

Word Count : 672

Gap theorem

Last Update:

Gap Theorem does not imply anything interesting for complexity classes such as P or NP, and it does not contradict the time hierarchy theorem or space hierarchy...

Word Count : 549

List of mathematical logic topics

Last Update:

Cook's theorem List of complexity classes Polynomial hierarchy Exponential hierarchy NP-complete Time hierarchy theorem Space hierarchy theorem Natural...

Word Count : 1012

List of theorems

Last Update:

metric spaces) Baker's theorem (number theory) Balian–Low theorem (Fourier analysis) Balinski's theorem (combinatorics) Banach–Alaoglu theorem (functional...

Word Count : 5996

List of computability and complexity topics

Last Update:

Turing reduction Savitch's theorem Space hierarchy theorem Speed Prior Speedup theorem Subquadratic time Time hierarchy theorem See the list of complexity...

Word Count : 466

PolyL

Last Update:

problem under logarithmic space many-one reductions but polyL does not due to the space hierarchy theorem. The space hierarchy theorem guarantees that DSPACE(logd...

Word Count : 319

Union theorem

Last Update:

Together with the speedup theorem, the gap theorem and the time and space hierarchy theorems it is a basis for hirarchies in complexity theory. McCreight, E...

Word Count : 290

Polynomial hierarchy

Last Update:

computational complexity theory, the polynomial hierarchy (sometimes called the polynomial-time hierarchy) is a hierarchy of complexity classes that generalize...

Word Count : 2690

Regular language

Last Update:

finite automata is known as Kleene's theorem (after American mathematician Stephen Cole Kleene). In the Chomsky hierarchy, regular languages are the languages...

Word Count : 3414

Borel hierarchy

Last Update:

mathematical logic, the Borel hierarchy is a stratification of the Borel algebra generated by the open subsets of a Polish space; elements of this algebra...

Word Count : 1732

Juris Hartmanis

Last Update:

space usage and proved the first space hierarchy theorem. In the same year they also proved that every context-free language has deterministic space complexity...

Word Count : 2502

Oracle machine

Last Update:

standard. In some contexts, such as the proof of the time and space hierarchy theorems, it is more useful to assume that the abstract machine defining...

Word Count : 2014

Borel set

Last Update:

separable metric space. Then X as a Borel space is isomorphic to one of R, Z, a finite space. (This result is reminiscent of Maharam's theorem.) Considered...

Word Count : 1793

Borel determinacy theorem

Last Update:

to show that Borel sets in Polish spaces have regularity properties such as the perfect set property. The theorem is also known for its metamathematical...

Word Count : 2018

PDF Search Engine © AllGlobal.net