翻訳と辞書 Words near each other ・ Product teardown ・ Product term ・ Product testing ・ Product topology ・ Product transfer security ・ Product type ・ Product-based planning ・ Product-determining step ・ Product-form solution ・ Product-service system ・ Product/market fit ・ Product/process distinction ・ Productalius ・ ProductCenter ・ Production ・ Production (computer science) ・ Production (economics) ・ Production (Mirwais LP) ・ Production and Decay of Strange Particles ・ Production and Operations Management ・ Production artist ・ Production assistant ・ Production Automotive Services ・ Production babies ・ Production Baobab ・ Production Bike Racing ・ Production blocking ・ Production board ・ Production brigade ・ Production budget Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Production (computer science) ： ウィキペディア英語版 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. A finite set of productions $P$ is the main component in the specification of a formal grammar (specifically a generative grammar). The other components are a finite set $N$ of nonterminal symbols, a finite set (known as an alphabet) $\backslash Sigma$ of terminal symbols that is disjoint from $N$ and a distinguished symbol $S\; \backslash in\; N$ that is the start symbol. In an unrestricted grammar, a production is of the form $u\; \backslash to\; v$ where $u$ and $v$ are arbitrary strings of terminals and nonterminals however $u$ may not be the empty string. If $v$ is the empty string, this is denoted by the symbol $\backslash epsilon$, or $\backslash lambda$ (rather than leave the right-hand side blank). So productions are of the form: :$(N\; \backslash cup\; \backslash Sigma)^$ *N(N \cup \Sigma)^ * \to (N \cup \Sigma)^ * where $\{\}^\{$ *} is the Kleene star operator, and $\backslash cup$ denotes set union. The other types of formal grammar in the Chomsky hierarchy impose additional restrictions on what constitutes a production. Notably in a context-free grammar, the left-hand side of a production must be a single nonterminal symbol. So productions are of the form: :$N\; \backslash to\; (N\; \backslash cup\; \backslash Sigma)^$ * ==Grammar generation== To generate a string in the language, one begins with a string consisting of only a single ''start symbol'', and then successively applies the rules (any number of times, in any order) to rewrite this string. This stops when we obtain a string containing only terminals. The language consists of all the strings that can be generated in this manner. Any particular sequence of legal choices taken during this rewriting process yields one particular string in the language. If there are multiple different ways of generating this single string, then the grammar is said to be ambiguous. For example, assume the alphabet consists of $a$ and $b$, with the start symbol $S$, and we have the following rules: : 1. $S\; \backslash rightarrow\; aSb$ : 2. $S\; \backslash rightarrow\; ba$ then we start with $S$, and can choose a rule to apply to it. If we choose rule 1, we replace $S$ with $aSb$ and obtain the string $aSb$. If we choose rule 1 again, we replace $S$ with $aSb$ and obtain the string $aaSbb$. This process is repeated until we only have symbols from the alphabet (i.e., $a$ and $b$). If we now choose rule 2, we replace $S$ with $ba$ and obtain the string $aababb$, and are done. We can write this series of choices more briefly, using symbols: $S\; \backslash Rightarrow\; aSb\; \backslash Rightarrow\; aaSbb\; \backslash Rightarrow\; aababb$. The language of the grammar is the set of all the strings that can be generated using this process: $\backslash$.R>R> 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Production (computer science)」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.