上下文無關(guān)文法（Context-Free Grammar, CFG）是一個(gè)4元組G=(V, T, S, P)，其中，V和T是不相交的有限集，S∈V，P是一組有限的產(chǎn)生式規(guī)則集，形如A→α，其中A∈V，且α∈(V∪T)*。V的元素稱為非終結(jié)符，T的元素稱為終結(jié)符，S是一個(gè)特殊的非終結(jié)符，稱為文法開始符。 設(shè)G=(V, T, S, P)是一個(gè)CFG，則G產(chǎn)生的語言是所有可由G產(chǎn)生的字符串組成的集合，即L(G)={x∈T* | Sx}。一個(gè)語言L是上下文無關(guān)語言（Context-Free Language, CFL），當(dāng)且僅當(dāng)存在一個(gè)CFG G，使得L=L(G)。 *⇒ 例如，設(shè)文法G：S→AB A→aA|a B→bB|b 則L(G)={a^nb^m | n,m>=1} 其中非終結(jié)符都是大寫字母，開始符都是S，終結(jié)符都是小寫字母。
標(biāo)簽： Context-Free Grammar CFG
上傳時(shí)間： 2013-12-10
上傳用戶：gaojiao1999
SVMcfg: Learns a weighted context free grammar from examples. Training examples (e.g. for natural language parsing) specify the sentence along with the correct parse tree. The goal is to predict the parse tree of new sentences.
標(biāo)簽： examples e.g. weighted Training
上傳時(shí)間： 2014-07-26
上傳用戶：zsjzc
Draak is a multi-language, macro compiler, meaning all syntax and code generation is defined in a single file. Draak is a single binary that is able to compile any context free language (like C, Pascal, Java) for any platform with only 1 file. Draak Compiler是一個(gè)多語言，宏編譯器，可以在一個(gè)單獨(dú)的文件中定義所有的語法和代碼生成。Draak 是一個(gè)單獨(dú)的二進(jìn)制文件，可以在任意平臺(tái)上只使用一個(gè)文件來編譯任何上下文無關(guān)的語言（類似 C, Pascal, Java）。
標(biāo)簽： multi-language generation compiler defined
上傳時(shí)間： 2013-12-30
上傳用戶：a673761058
Computer science as an academic discipline began in the 1960’s. Emphasis was on programming languages, compilers, operating systems, and the mathematical theory that supported these areas. Courses in theoretical computer science covered finite automata, regular expressions, Context-Free languages, and computability. In the 1970’s, the study of algorithms was added as an important component of theory. The emphasis was on making computers useful. Today, a fundamental change is taking place and the focus is more on a wealth of applications. There are many reasons for this change. The merging of computing and communications has played an important role. The enhanced ability to observe, collect, and store data in the natural sciences, in commerce, and in other fields calls for a change in our understanding of data and how to handle it in the modern setting. The emergence of the web and social networks as central aspects of daily life presents both opportunities and challenges for theory.
標(biāo)簽： Foundations Science Data of
上傳時(shí)間： 2020-06-10
上傳用戶：shancjb
free BSD
上傳時(shí)間： 2013-12-11
上傳用戶：731140412
中文譯名《最優(yōu)C/C++編程秘訣》。書中對(duì)new/delete、malloc/free，構(gòu)造/析構(gòu)函數(shù)等等C/C++難點(diǎn)問題有詳細(xì)深入的講解。
標(biāo)簽： delete malloc free new
上傳時(shí)間： 2013-12-31
上傳用戶：dongbaobao
一個(gè)FREE編譯器原碼，用于學(xué)習(xí)LEX和YA
上傳時(shí)間： 2014-01-17
上傳用戶：netwolf
FREE embed os FOR ARM ,51等多種MCU
上傳時(shí)間： 2015-01-28
上傳用戶：chenbhdt
Java Clock is a FREE Java applet used to display a clock on your Web pages. You can display either analog or digital clock. The full source code of this applet is also available (visit my home page to download it). You may use this applet on your Web pages WITHOUT paying me fee or royalty as long as credit is given (a link to my home page is enough).
標(biāo)簽： display Java applet either
上傳時(shí)間： 2014-01-12
上傳用戶：woshiayin
free software based on toyFDTD
標(biāo)簽： software toyFDTD based free
上傳時(shí)間： 2015-02-16
上傳用戶：talenthn
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