In computer science, an ambiguous grammar is a context-free grammar for which there exists a string that can have more than one leftmost derivation or parse tree.[1] Every non-empty context-free language admits an ambiguous grammar by introducing e.g. a duplicate rule. A language that only admits ambiguous grammars is called an inherently ambiguous language. Deterministic context-free grammars are always unambiguous, and are an important subclass of unambiguous grammars; there are non-deterministic unambiguous grammars, however.
For computer programming languages, the reference grammar is often ambiguous, due to issues such as the dangling else problem. If present, these ambiguities are generally resolved by adding precedence rules or other context-sensitive parsing rules, so the overall phrase grammar is unambiguous.[citation needed] Some parsing algorithms (such as (Earley[2] or GLR parsers) can generate sets of parse trees (or "parse forests") from strings that are syntactically ambiguous.[3]
^Willem J. M. Levelt (2008). An Introduction to the Theory of Formal Languages and Automata. John Benjamins Publishing. ISBN 978-90-272-3250-2.
^Scott, Elizabeth (April 1, 2008). "SPPF-Style Parsing From Earley Recognizers". Electronic Notes in Theoretical Computer Science. 203 (2): 53–67. doi:10.1016/j.entcs.2008.03.044.
In computer science, an ambiguousgrammar is a context-free grammar for which there exists a string that can have more than one leftmost derivation or...
results in nested conditionals being ambiguous. Formally, the reference context-free grammar of the language is ambiguous, meaning there is more than one correct...
Syntactic ambiguity, also known as structural ambiguity, amphiboly, or amphibology, is characterized by the potential for a sentence to yield multiple...
see Ambiguousgrammar. Usually, semantic and syntactic ambiguity go hand in hand. The sentence "We saw her duck" is also syntactically ambiguous. Conversely...
Grammar designated 4 March as National Grammar Day in 2008. Ambiguousgrammar Constraint-based grammar Grammeme Harmonic Grammar Higher order grammar...
context-free grammars (CFGs), but they have a different interpretation: the choice operator selects the first match in PEG, while it is ambiguous in CFG. This...
of ambiguous programming languages, which are not reported at compile-time, and which are introduced not by human error, but by ambiguousgrammar. The...
parses for ambiguousgrammars such as for human languages. While LR(k) grammars have equal generative power for all k≥1, the case of LR(0) grammars is slightly...
The LL(k) grammars therefore exclude all ambiguousgrammars, as well as all grammars that contain left recursion. Any context-free grammar can be transformed...
semantically ambiguous when it can have multiple meanings. The higher the number of synonyms a word has, the higher the degree of ambiguity. Like other...
conveniently be read as an ambiguousgrammar generating only the sentence parsed, but with the same ambiguity as the original grammar, and the same parse trees...
science, a chart parser is a type of parser suitable for ambiguousgrammars (including grammars of natural languages). It uses the dynamic programming approach—partial...
require exponential time and space complexity while parsing ambiguous context-free grammars, more sophisticated algorithms for top-down parsing have been...
property of being in possession of a car). Amphiboly Aberrant decoding Ambiguousgrammar Dog-whistle politics Essentially contested concept Heterosemy Homograph...
language should do. Further, LLMs often fail to decipher complex or ambiguousgrammar cases that rely on understanding the meaning of language. As an example...
extension of an LR parser algorithm to handle non-deterministic and ambiguousgrammars. The theoretical foundation was provided in a 1974 paper by Bernard...
an argument. It is a type of ambiguity that stems from a phrase having two or more distinct meanings, not from the grammar or structure of the sentence...
And the mome raths outgrabe. Other nonsense verse uses muddled or ambiguousgrammar as well as invented words, as in John Lennon's "The Faulty Bagnose":...
general context-free grammars by use of curtailment. In 2006, Frost and Hafiz described an algorithm which accommodates ambiguousgrammars with direct left-recursive...
is a backtracking LL(∞) parser that is capable of parsing rather ambiguousgrammars. Spirit can be used for both lexing and parsing, together or separately...
outlines the grammar of the Dutch language, which shares strong similarities with German grammar and also, to a lesser degree, with English grammar. Vowel length...
(also called functors) are words that have little lexical meaning or have ambiguous meaning and express grammatical relationships among other words within...
spurious, a result of the approximate calculation using Follow(A). A grammar which is ambiguous will have unavoidable shift/reduce conflicts or reduce/reduce...
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