Finite thickness

From Wikipedia, the free encyclopedia

In formal language theory, a class of languages \mathcal L has finite thickness if for every string s, there are only finite consistent languages in \mathcal L. This condition was introduced by Dana Angluin in connection with learning, as a sufficient condition for language identification in the limit. The related notion of M-finite thickness

We say that \mathcal L satisfies the MEF-condition if for each string s and each consistent language L in the class, there is a minimal consistent language in \mathcal L, which is a sublanguage of L. Symmetrically, we say that \mathcal L satisfies the MFF-condition if for every string s there are only finite minimal consistent languages in \mathcal L. Finally, \mathcal L is said to have M-finite thickness if it satisfies both the MEF and MFF conditions.

M-finite thickness should be compared with finite thickness. While finite thickness implies the existence of a mind change bound, M-finite thickness does not. For example, let {Ln} be a class of languages such that L_0 \subseteq L_1 \subseteq \ldots then there is no mind change bound for this class.


Advanced Search
Included Web Search Engines


Safe Search

close

Top Matching Results

Occasionally Search.com will highlight specialized results that are based on the context of your query. Examples of specialized results include specific links to news, images, or video.

Top Matching Results may highlight information from other Search.com pages, content from the CNET Network of sites, or third party content. The listings are based purely on relevance. Search.com does not receive payment for listings in this section but our partners that provide this data may get paid for listing these products.

Sponsored Links

This section contains paid listings which have been purchased by companies that want to have their sites appear for specific search terms and related content. These listings are administered, sorted and maintained by a third party and are not endorsed by Search.com.

Search Results

Search.com sends your search query to several search engines at one time and integrates the results into one list which has been sorted by relevance using Search.com's proprietary algorithm. You can customize the list of search engines included in your metasearch from the preferences.

The search engines that are used in your metasearch may allow companies to pay to have their Web sites included within the results. To view the Paid Inclusion policy for a specific search engine, please visit their Web site. Search.com does not accept payment or share revenue with any search engine partner for listings in this section.