Topic
Left recursion
About: Left recursion is a research topic. Over the lifetime, 243 publications have been published within this topic receiving 4034 citations.
Papers published on a yearly basis
Papers
1 Mar 2000
TL;DR: This paper describes a simple and powerful query language based on pattern matching and shows that it can be expressed using structural recursion, which is introduced as a top-down, recursive function, similar to the way XSL is defined on XML trees.
Abstract: This paper presents structural recursion as the basis of the syntax and semantics of query languages for semistructured data and XML. We describe a simple and powerful query language based on pattern matching and show that it can be expressed using structural recursion, which is introduced as a top-down, recursive function, similar to the way XSL is defined on XML trees. On cyclic data, structural recursion can be defined in two equivalent ways: as a recursive function which evaluates the data top-down and remembers all its calls to avoid infinite loops, or as a bulk evaluation which processes the entire data in parallel using only traditional relational algebra operators. The latter makes it possible for optimization techniques in relational queries to be applied to structural recursion. We show that the composition of two structural recursion queries can be expressed as a single such query, and this is used as the basis of an optimization method for mediator systems. Several other formal properties are established: structural recursion can be expressed in first-order logic extended with transitive closure; its data complexity is PTIME; and over relational data it is a conservative extension of the relational calculus. The underlying data model is based on value equality, formally defined with bisimulation. Structural recursion is shown to be invariant with respect to value equality.
309 citations
11 Aug 2009
TL;DR: This work gives an alternative, type-based verification method for modal mu-calculus model checking of trees generated by order-n recursion scheme, and its correctness proof is comparatively easy to understand.
Abstract: The model checking of higher-order recursion schemes has important applications in the verification of higher-order programs. Ong has previously shown that the modal mu-calculus model checking of trees generated by order-n recursion scheme is n-EXPTIME complete, but his algorithm and its correctness proof were rather complex. We give an alternative, type-based verification method: Given a modal mu-calculus formula, we can construct a type system in which a recursion scheme is typable if, and only if, the (possibly infinite, ranked) tree generated by the scheme satisfies the formula. The model checking problem is thus reduced to a type checking problem. Our type-based approach yields a simple verification algorithm, and its correctness proof (constructed without recourse to game semantics) is comparatively easy to understand. Furthermore, the algorithm is polynomial-time in the size of the recursion scheme, assuming that the formula and the largest order and arity of non-terminals of the recursion scheme are fixed.
194 citations
23 Aug 2004
TL;DR: An efficient bit-vector-based CKY-style parser for context-free parsing is presented, which computes a compact parse forest representation of the complete set of possible analyses for large treebank grammars and long input sentences.
Abstract: An efficient bit-vector-based CKY-style parser for context-free parsing is presented. The parser computes a compact parse forest representation of the complete set of possible analyses for large treebank grammars and long input sentences. The parser uses bit-vector operations to parallelise the basic parsing operations. The parser is particularly useful when all analyses are needed rather than just the most probable one.
154 citations
TL;DR: This paper describes an implementation of recursion which is both correct and optimal in a general class of sequential languages, and therefore constitutes an attractive alternative to both “ call-by-name” and “call- by-value”.
144 citations
TL;DR: A connectionist model embodying this alternative theory is outlined, along with simulation results showing that the model is capable of constituent-like generalizations and that it can fit human data regarding the differential processing difficulty associated with center-embeddings in German and cross-dependencies in Dutch.
Abstract: Most current approaches to linguistic structure suggest that language is recursive, that recursion is a fundamental property of grammar, and that independent performance constraints limit recursive abilities that would otherwise be infinite. This article presents a usage-based perspective on recursive sentence processing, in which recursion is construed as an acquired skill and in which limitations on the processing of recursive constructions stem from interactions between linguistic experience and intrinsic constraints on learning and processing. A connectionist model embodying this alternative theory is outlined, along with simulation results showing that the model is capable of constituent-like generalizations and that it can fit human data regarding the differential processing difficulty associated with center-embeddings in German and cross-dependencies in Dutch. Novel predictions are furthermore derived from the model and corroborated by the results of four behavioral experiments, suggesting that acquired recursive abilities are intrinsically bounded not only when processing complex recursive constructions, such as center-embedding and cross-dependency, but also during processing of the simpler, right- and left-recursive structures.
144 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 2 |
| 2020 | 3 |
| 2019 | 1 |
| 2018 | 3 |
| 2017 | 5 |
| 2016 | 7 |