Formal languages

2017-07-30T05:21:03+03:00[Europe/Moscow] en true Backus–Naur Form, Formal grammar, Regular expression, String (computer science), Turing machine, Context-sensitive grammar, Two-level grammar, Abstract syntax tree, Metacharacter, Production (computer science), Abstract rewriting system, Descriptive interpretation, Tell-tale, Erasing rule, Simple precedence grammar, Antimatroid flashcards Formal languages
Click to flip
  • Backus–Naur Form
    In computer science, Backus–Naur Form or Backus Normal Form (BNF) is one of the two main notation techniques for context-free grammars, often used to describe the syntax of languages used in computing, such as computer programming languages, document formats, instruction sets and communication protocols; the other main technique for writing context-free grammars is the van Wijngaarden form.
  • Formal grammar
    In formal language theory, a grammar (when the context is not given, often called a formal grammar for clarity) is a set of production rules for strings in a formal language.
  • Regular expression
    In theoretical computer science and formal language theory, a regular expression (sometimes called a rational expression) is a sequence of characters that define a search pattern, mainly for use in pattern matching with strings, or string matching, i.
  • String (computer science)
    In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable.
  • Turing machine
    A Turing machine is an abstract machine that manipulates symbols on a strip of tape according to a table of rules; to be more exact, it is a mathematical model of computation that defines such a device.
  • Context-sensitive grammar
    A context-sensitive grammar (CSG) is a formal grammar in which the left-hand sides and right-hand sides of any production rules may be surrounded by a context of terminal and nonterminal symbols.
  • Two-level grammar
    A two-level grammar is a formal grammar that is used to generate another formal grammar , such as one with an infinite rule set .
  • Abstract syntax tree
    In computer science, an abstract syntax tree (AST), or just syntax tree, is a tree representation of the abstract syntactic structure of source code written in a programming language.
  • Metacharacter
    A metacharacter is a character that has a special meaning (instead of a literal meaning) to a computer program, such as a shell interpreter or a regular expression engine.
  • Production (computer science)
    A production or production rule in computer science is a rewrite rule specifying a symbol substitution that can be recursively performed to generate new symbol sequences.
  • Abstract rewriting system
    In mathematical logic and theoretical computer science, an abstract rewriting system (also (abstract) reduction system or abstract rewrite system; abbreviation ARS) is a formalism that captures the quintessential notion and properties of rewriting systems.
  • Descriptive interpretation
    According to Rudolf Carnap, in logic, an interpretation is a descriptive interpretation (also called a factual interpretation) if at least one of the undefined symbols of its formal system becomes, in the interpretation, a descriptive sign (i.e., the name of single objects, or observable properties).
  • Tell-tale
    A tell-tale or telltale is an indicator, signal, or sign that conveys the status of a situation, mechanism, or system.
  • Erasing rule
    In a formal grammar, an erasing rule is a rule which maps a string of symbols to the empty string (ε).
  • Simple precedence grammar
    A simple precedence grammar is a context-free formal grammar that can be parsed with a simple precedence parser.
  • Antimatroid
    In mathematics, an antimatroid is a formal system that describes processes in which a set is built up by including elements one at a time, and in which an element, once available for inclusion, remains available until it is included.