Probabilistic Parsing Strategies

TL;DR

This paper explores the relationship between symbolic and probabilistic context-free parsing strategies, identifying conditions for probability preservation and extending previous findings in the field.

Contribution

It introduces new theoretical conditions for probability preservation in parsing strategies and generalizes prior results, including negative findings on generalized LR parsing.

Findings

Probability preservation is possible under correct-prefix and strong predictiveness properties.

Generalizes existing results on parsing strategies.

Provides negative results on generalized LR parsing.

Abstract

We present new results on the relation between purely symbolic context-free parsing strategies and their probabilistic counter-parts. Such parsing strategies are seen as constructions of push-down devices from grammars. We show that preservation of probability distribution is possible under two conditions, viz. the correct-prefix property and the property of strong predictiveness. These results generalize existing results in the literature that were obtained by considering parsing strategies in isolation. From our general results we also derive negative results on so-called generalized LR parsing.