Talk:L (complexity)

This article is rated Start-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects:

Mathematics Mid‑priority This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MathematicsWikipedia:WikiProject MathematicsTemplate:WikiProject Mathematicsmathematics Mid This article has been rated as Mid-priority on the project's priority scale. Computer science Mid‑importance This article is within the scope of WikiProject Computer science, a collaborative effort to improve the coverage of Computer science related articles on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Computer scienceWikipedia:WikiProject Computer scienceTemplate:WikiProject Computer scienceComputer science Mid This article has been rated as Mid-importance on the project's importance scale. Things you can help WikiProject Computer science with: Here are some tasks awaiting attention: Article requests : Requested articles/Applied arts and sciences/Computer science, computing, and Internet Cleanup : Computer science articles needing attention Computer science articles needing expert attention Copyedit : Computing Expand : Computer science Infobox : Computer science articles without infoboxes Maintain : Timeline of computing 2020–present Photo : Find pictures for the biographies of computer scientists (see List of computer scientists) Computing articles needing images Stubs : Computer science stubs Unreferenced : WikiProject Computer science/Unreferenced BLPs Project-related : Tag all relevant articles in Category:Computer science and sub-categories with {{WikiProject Computer science}}

I appear to be too stupid to figure out how to use the citation system, but the citation is in the references, namely Reingold's paper. If the flag is asking for the fact that the result appeared in October 2004 (which apparently was significant since someone else proved a worse bound a few weeks after Reingold), see http://blog.computationalcomplexity.org/2004/11/undirected-connectivity-in-log-space.html

I just added a section to explain why logspace theory can be usefull outside of the computational world, but I have no practical example, if someone has got any link it could be usefull. (The problem beeing mostly that since examples would be of impossibility, it wouldn't have "real life" use, the logspace algorithm one can see in complexity are of no real world use because of their uge time complexity) —Preceding unsigned comment added by Arthur MILCHIOR (talk • contribs) 23:35, 17 May 2010 (UTC)Reply

This page really should have a section on L-complete problems. I will try and add some later when I have more time. However, if anybody wants to beat me to it, here are some:

• Deterministic reachability is perhaps the canonical one.
• Undirected reachability follows from L=SL (and is already in the article).
• SAT(2) (CNF-SAT where each variable occurs at most twice) -- Jan Johannsen. Satisfiability Problems Complete for Deterministic Logarithmic Space. In Proceedings of STACS'2004.
• Planar graph isomorphism -- Samir Datta, Nutan Limaye, Prajakta Nimbhorkar, Thomas Thierauf, and Fabian Wagner. Planar Graph Isomorphism is in Log-Space. In Proceedings of the 2009 24th Annual IEEE Conference on Computational Complexity (CCC '09). — Preceding unsigned comment added by 71.192.228.96 (talk) 14:18, 9 June 2011 (UTC)Reply

I think the page should also contain opinions on that, and what the equality or inequality would entail. We have that kind of info in the article for the much better known P versus NP problem. Tijfo098 (talk) 23:12, 9 November 2012 (UTC)Reply