Backus–Naur form

<p>In <a href="/facts/Computer_science/lN3pEyPz">computer science</a>, Backus–Naur form (BNF, pronounced /ˌbækəs ˈnaʊər/), also known as Backus normal form, is a notation system for defining the <a href="/facts/Syntax_(programming_languages)/zM5oInza">syntax</a> of <a href="/facts/Programming_language/cWTYbgWa">programming languages</a> and other <a href="/facts/Formal_language/crDTyP8q">formal languages</a>, developed by <a href="/facts/John_Backus/pqELHDh6">John Backus</a> and <a href="/facts/Peter_Naur/S1X7AHfj">Peter Naur</a>. It is a <a href="/facts/Metasyntax/Mmb3tj6n">metasyntax</a> for <a href="/facts/Context-free_grammar/yu1FFdK4">context-free grammars</a>, providing a precise way to outline the rules of a language's structure. 
</p><p>It has been widely used in official specifications, manuals, and textbooks on <a href="/facts/Programming_language_theory/MfecfTFI">programming language theory</a>, as well as to describe <a href="/facts/Document_format/ofD5voGr">document formats</a>, <a href="/facts/Instruction_set/8p8vwUeE">instruction sets</a>, and <a href="/facts/Communication_protocol/5uady7cB">communication protocols</a>. Over time, variations such as <a href="/facts/Extended_Backus%E2%80%93Naur_form/89KI2QTe">extended Backus–Naur form</a> (EBNF) and <a href="/facts/Augmented_Backus%E2%80%93Naur_form/coNbJGD2">augmented Backus–Naur form</a> (ABNF) have emerged, building on the original framework with added features.
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Backus–Naur form open-in-new

Backus–Naur form