polynomial space
polynomial space A way of characterizing the complexity of an algorithm. If the space complexity (see complexity measure) is polynomially bounded, the algorithm is said to be executable in polynomial space. Many problems for which no polynomial time algorithms have been found, nevertheless can easily be solved in an amount of space bounded by a polynomial in the length of the input.
Formally PSPACE is defined as the class of formal languages that are recognizable in polynomial space. Defining P and NP as the classes of languages recognizable in polynomial time and recognizable in polynomial time on a nondeterministic Turing machine, respectively (see P=NP question), it can be shown that P is a subset of PSPACE and that NP is also a subset of PSPACE. It is not known, however, whether NP = PSPACE
although it is conjectured that they are different, i.e. that there exist languages in PSPACE that are not in NP.
Many problems associated with recognizing whether a player of a certain game (like GO) has a forced win from a given position are PSPACEcomplete, which is defined in a similar manner to NPcompleteness (see P=NP question). This implies that such languages can be recognized in polynomial time only if PSPACE = P
Such problems can thus be considered to be even harder than NPcomplete problems.
Cite this article
Pick a style below, and copy the text for your bibliography.

MLA

Chicago

APA
"polynomial space." A Dictionary of Computing. . Encyclopedia.com. 17 Oct. 2018 <http://www.encyclopedia.com>.
"polynomial space." A Dictionary of Computing. . Encyclopedia.com. (October 17, 2018). http://www.encyclopedia.com/computing/dictionariesthesaurusespicturesandpressreleases/polynomialspace
"polynomial space." A Dictionary of Computing. . Retrieved October 17, 2018 from Encyclopedia.com: http://www.encyclopedia.com/computing/dictionariesthesaurusespicturesandpressreleases/polynomialspace
Citation styles
Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).
Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.
Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the mostrecent information available at these sites:
Modern Language Association
The Chicago Manual of Style
http://www.chicagomanualofstyle.org/tools_citationguide.html
American Psychological Association
Notes:
 Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
 In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.