Recursively Enumerable

Some articles on recursively enumerable, recursively:

Recognizable Language - Closure Properties
... Recursively enumerable languages are closed under the following operations ... That is, if L and P are two recursively enumerable languages, then the following languages are recursively enumerable as well the Kleene star of L the concatenation of L and P the union ... Note that recursively enumerable languages are not closed under set difference or complementation ...
Alpha Recursion Theory - Results in Recursion
... Shore's splitting theorem Let A be recursively enumerable and regular ... There exist recursively enumerable such that Shore's density theorem Let A, C be α-regular recursively enumerable sets such that then there exists a regular α-recursively enumerable set B such that ...
Computability - Power of Automata - Power of Turing Machines - Beyond Recursively Enumerable Languages
... The halting language is therefore recursively enumerable ... possible to construct languages which are not even recursively enumerable, however ... To see that this language is not recursively enumerable, imagine that we construct a Turing machine M which is able to give a definite answer for all ...
Recognizable Language
... logic and computer science, a formal language is called recursively enumerable (also recognizable, partially decidable or Turing-acceptable) if it is a recursively ... Recursively enumerable languages are known as type-0 languages in the Chomsky hierarchy of formal languages ... All regular, context-free, context-sensitive and recursive languages are recursively enumerable ...
Kleene's O - Basic Properties Of
... of this system of ordinal notations under successor and effective limits.) is not recursively enumerable, but there is a recursively enumerable relation which agrees with precisely on members of ... any notation, the set of notations below is recursively enumerable ...