Background. The halting problem is a decision problem about properties of computer programs on a fixed Turing-complete model of computation, i.e., all programs that can be written in some given programming language that is general enough to be equivalent to a Turing machine. The problem is to determine, given a program and an input to the program, whether the program …

In formal language theory, a context-free grammar (CFG) is a formal grammar whose production rules are of the form with a single nonterminal symbol, and a string of terminals and/or nonterminals (can be empty). A formal grammar is "context-free" if its production rules can be applied regardless of the context of a nonterminal. No matter which symbols surround it, the …

The incompleteness theorem is closely related to several results about undecidable sets in recursion theory.. Stephen Cole Kleene () presented a proof of Gödel's incompleteness theorem using basic results of computability theory.One such result shows that the halting problem is undecidable: there is no computer program that can correctly determine, given any program P …

The context-free nature of the language makes it simple to parse with a pushdown automaton. Determining an instance of the membership problem; i.e. given a string , determine whether () where is the language generated by a given grammar ; is also known as recognition.Context-free recognition for Chomsky normal form grammars was shown by Leslie G. Valiant to be …

A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical.They are a kind of computer language.. The description of a programming language is usually split into the two components of syntax (form) and semantics (meaning), which are usually defined …

The problem asks for an algorithm that considers, as input, a statement and answers "Yes" or "No" according to whether the statement is universally valid, ... Martin Davis, "The Undecidable, Basic Papers on Undecidable Propositions, Unsolvable Problems And Computable Functions", Raven Press, New York, 1965. Turing's paper is #3 in this volume.

A distributed system is a system whose components are located on different networked computers, which communicate and coordinate their actions by passing messages to one another from any system. Distributed computing is a field of computer science that studies distributed systems.. The components of a distributed system interact with one another in order to achieve …

External links. Tony Cassandra's POMDP pages with a tutorial, examples of problems modeled as POMDPs, and software for solving them.; pomdp: Solver for Partially Observable Markov Decision Processes (POMDP) an R package providing an interface to Tony Cassandra's POMDP solver. zmdp, a POMDP solver by Trey Smith; APPL, a fast point-based POMDP solver; …

List of undecidable problems; List of unsolved deaths; Lists of problems This page was last edited on 3 December 2022, at 21:59 (UTC). Text is available under the Creative Commons Attribution-ShareAlike License 3.0; additional terms may apply. By using this site, you agree ...

A formula is a semantic consequence within some formal system of a set of statements if and only if there is no model in which all members of are true and is false. This is denoted ,.Or, in other words, the set of the interpretations that make all members of true is a subset of the set of the interpretations that make true.. Modal accounts. Modal accounts of logical consequence are …