ThreeF

摘要： In the theory offormal languagesincomputability theory, apumping lemmaorpumping argumentstates that, for a particular language to be a member of a language class, any sufficiently long string in the language contains a section, or sections, that can be removed, or repeated any number of times, with 阅读全文

摘要： Informal language theory, acontext-free grammar(CFG) is aformal grammarin which everyproduction ruleis of the formV→wwhereVis asinglenonterminalsymbol, andwis a string ofterminalsand/or nonterminals (wcan be empty). A formal grammar is considered "context free" when its production rules ca 阅读全文

摘要： This article is about a technical term inmathematicsandcomputer science. For related studies about natural languages, seeGrammar framework. For formal modes of speech in natural languages, seeRegister (sociolinguistics).Inmathematics,computer science, andlinguistics, aformal languageis asetofstrings 阅读全文

摘要： Incomputer science, acanonical LR parserorLR(1) parseris anLR(k)parser fork=1, i.e. with a singlelookaheadterminal. The special attribute of this parser is that all LR(k) parsers withk>1can be transformed into a LR(1) parser.[1]It can handle alldeterministic context-free languages[1]. In the past 阅读全文

摘要： Deterministic context-free languageFrom Wikipedia, the free encyclopediaInformal language theory,deterministic context-free languages(DCFL) are aproper subsetofcontext-free languages. They are the context-free languages that can be accepted by adeterministic pushdown automaton.Contents[hide]1Descrip 阅读全文